A place for play? The influence of the home physical environment on children’s physical activity and sedentary behaviour

  • Clover Maitland1Email author,

    Affiliated with

    • Gareth Stratton1, 2,

      Affiliated with

      • Sarah Foster3,

        Affiliated with

        • Rebecca Braham1 and

          Affiliated with

          • Michael Rosenberg1

            Affiliated with

            International Journal of Behavioral Nutrition and Physical Activity201310:99

            DOI: 10.1186/1479-5868-10-99

            Received: 3 October 2012

            Accepted: 14 August 2013

            Published: 17 August 2013

            Abstract

            The home environment is an important influence on the sedentary behaviour and physical activity of children, who have limited independent mobility and spend much of their time at home. This article reviews the current evidence regarding the influence of the home physical environment on the sedentary behaviour and physical activity of children aged 8–14 years. A literature search of peer reviewed articles published between 2005 and 2011 resulted in 38 observational studies (21 with activity outcomes, 23 with sedentary outcomes) and 11 experimental studies included in the review. The most commonly investigated behavioural outcomes were television watching and moderate to vigorous physical activity. Media equipment in the home and to a lesser extent the bedroom were positively associated with children’s sedentary behaviour. Physical activity equipment and the house and yard were not associated with physical activity, although environmental measures were exclusively self-reported. On the other hand, physical activity equipment was inversely associated with sedentary behaviours in half of studies. Observational studies that investigated the influence of the physical and social environment within the home space, found that the social environment, particularly the role of parents, was important. Experimental studies that changed the home physical environment by introducing a television limiting device successfully decreased television viewing, whereas the influence of introducing an active video game on activity outcomes was inconsistent. Results highlight that the home environment is an important influence on children’s sedentary behaviour and physical activity, about which much is still unknown. While changing or controlling the home physical environment shows promise for reducing screen based sedentary behaviour, further interventions are needed to understand the broader impact of these changes. Future studies should prioritise investigating the influence of the home physical environment, and its interaction with the social environment, on objectively measured sedentary time and home context specific behaviours, ideally including technologies that allow objective measures of the home space.

            Keywords

            Home environment Physical activity Sedentary behaviour Children Adolescents Review

            Introduction

            Changes to the environment in recent years have contributed to an increase in sedentary behaviour and a decline in activity [1]. The home environment is an important sphere of influence on the physical activity (PA) and sedentary behaviour of children. It is especially relevant for those who have limited independent mobility and spend much of their time at home and indoors [2, 3], thereby potentially affecting PA participation and resultant health outcomes [46]. More recently, time spent sedentary, in particular watching television, has been associated with detrimental health effects including overweight and obesity, reduced fitness and poorer social and cognitive skills [7, 8]. Still, many children do not meet health recommendations for PA and sedentary behaviour [9, 10]. Thus, understanding the potential impact of the home environment on the sedentary and activity behaviours of children is vital for developing effective interventions.

            Sedentary behaviour and PA are part of a movement continuum [11]. PA can be of light, moderate or vigorous intensity and at home may include unstructured play, exercise and chores [12]. Sedentary behaviours use low levels of energy (≤ 1.5 METs) while sitting or reclining, such as watching television, using a computer and reading, and are distinct from insufficient PA, also termed as inactivity [1]. Notably, reviews have concluded the independence of moderate to vigorous physical activity (MVPA) and sedentary behaviour in children [1316]. Therefore while sedentary behaviour and PA coexist in the home space, they are distinct behaviours influenced by different factors [11].

            Ecological models emphasise individual, social and physical environmental influences on PA and sedentary behaviour [13, 1719]. Consequently, a large body of literature exists on social environmental influences [20] and the built environment at the neighbourhood level [21, 22], while the home physical environment has received less attention. Qualitative studies have identified lack of yard space and sedentary entertainment options, such as televisions and computers, as barriers to children’s PA, especially active play [2326]. These factors, along with home design, have also been noted as influences on electronic media use [27]. However, previous reviews of correlates have not located any studies that have investigated the home physical environment with the exception of PA and media equipment [13, 14, 16, 28, 29], or considered interactions between physical and social environmental influences within the home space.

            Across the world, home environments are rapidly changing. House sizes in countries such as Australia and the USA have increased, while block and yard sizes have decreased [30]. In contrast lack of indoor and outdoor space is a concern in the UK [31, 32]. Additionally, new electronic media technologies such as wireless broadband, multifunctional devices and interactive video games are now an integral part of homes in developed countries. Time use studies have found that leisure time at home indoors is more likely to be sedentary, while time at home in the garden is more likely to be active [33, 34]. Accordingly, there is a potentially important link between location within the home space and children’s PA and sedentary behaviours.

            Thus, it is timely to review the influence of the home physical environment on children’s PA and sedentary behaviour. The aims of this review were to: (1) examine the impact of interventions that change the home physical environment on children’s PA and sedentary behaviours; (2) summarise the association between home physical environmental factors and children’s PA and sedentary behaviours; (3) explore the relationship of physical and social environmental factors operating within the home space; and (4) highlight current evidence limitations, measurement issues and future research directions. The time of transition from childhood to adolescence, known as preadolescence, represents a specific stage [35] and has been chosen as PA levels decrease [36, 37] and sedentary screen based behaviour is high [13, 38]. The review commences in 2005 to reflect recent changes in homes and build upon evidence from previous reviews of PA and sedentary behaviour by van der Horst et al. [14] and others [28, 29].

            Methods

            Search procedure

            Medline, Web of Science, PsychInfo and Sportdiscus databases were searched for quantitative studies examining the relationship between the physical home environment and preadolescent children’s sedentary behaviours and PA. Combinations of key words were entered in three levels: children; activity; and home environment (Figure 1). The search was limited to English language peer reviewed journal articles published between 2005 and 2011.
            http://static-content.springer.com/image/art%3A10.1186%2F1479-5868-10-99/MediaObjects/12966_2012_Article_792_Fig1_HTML.jpg
            Figure 1

            Literature search flow chart.

            Inclusion/Exclusion criteria

            Inclusion criteria were: (1) sample of healthy children with mean age of between eight and 14 years (at baseline); and (2) outcome variable of sedentary behaviour or PA, including overall time spent sedentary or in PA, or time spent in specific behaviours that potentially occur within the home, such as television watching, video game play, active play and leisure time PA. While preadolescence has most commonly been defined as nine to 13 years [35], some studies have also included those aged eight and 14 years within this group [39]. Therefore, this age range was chosen to ensure all appropriate studies were included. Where studies included multiple age groups only the results from groups with a mean age of eight to 14 years were included in the review. Studies with outcomes of vigorous PA only, school based PA, active transport and structured sport were excluded. Observational studies were required to: (1) include at least one home physical environmental factor as an independent variable, for example home equipment or yard size; and (2) examine an association between the independent and outcome variable. Studies that included only neighbourhood level built environmental variables or home social environmental variables were excluded. Studies with combined independent measures, such as home and neighbourhood facilities, were also excluded. Experimental studies were included if they: (1) contained at least one strategy that changed the home physical environment, such as adding or removing equipment; and (2) reported changes from baseline in the outcome variable.

            Selection process

            Articles were screened in three phases. One reviewer read the title, then abstract and finally the full text, eliminating articles that did not meet the inclusion criteria at each screening phase. Twenty per cent of articles remaining at abstract level were independently screened by a second reviewer to confirm eligibility. Where ambiguity remained, a conclusion was reached by discussion between reviewers. Reference lists from selected articles and relevant review papers were searched for additional articles meeting inclusion criteria.

            Quality assessment

            To identify the best available evidence and provide a guide to quality, each paper was assessed according to National Institute for Health and Clinical Excellence (NICE) quality appraisal checklists [40]. Each article received an overall score for internal and external validity, with ‘-’ representing the lowest validity (few criteria fulfilled); ‘+’ representing moderate validity (some criteria fulfilled); and ‘++’ representing the highest validity (all or most criteria fulfilled).

            Data analysis

            Evidence tables summarising the study population, independent and outcome variables, analysis, results, quality assessment and intervention (where applicable), were constructed separately for observational and intervention studies according to NICE methods [40]. To summarise observational studies, all home physical environmental variables were categorised into: house and yard, PA equipment, media equipment, and bedroom media equipment. Home social environmental variables were categorised into: family rules, family social support (encouragement and co-participation/viewing) and family behaviour (sedentary behaviour and PA). As papers included a wide variety of sedentary behaviour and PA outcome variables, studies were designated as having either a sedentary or PA outcome and results were analysed in these two groups. Studies investigating both outcomes were included in both groups. Positive (+), negative (−) and null (0) associations significant at p<0.05 from the highest level of multivariate analysis were extracted and are presented in Tables 1, 2 and 3, unless noted. Where studies analysed data by gender these results are reported separately in the Tables. For studies including analysis of multiple groups based on other criteria (e.g. age or country groups), time specific outcomes (e.g. weekend vs weekday screen time) or reporting methods (e.g. parent and self-report), at least half of the analyses must have shown an association in the reported direction. Results of studies were synthesised by totalling the number of studies reporting an association in a given direction. These totals are reported in the written results to provide overall trends for each of the key home environmental variables.
            Table 1

            Summary of observational studies with sedentary behaviour outcomes only

            Author (Year); Country

            Sample characteristics (Number, Age, % Male)

            Outcome variables

            Home physical and social environment independent variables

            Adjustments

            Internal validity

            External validity

            House & yard

            PA equipment

            Media equipment

            BR media equipment

            Family rules

            Family support

            Family behaviour

            Sedentary Outcome Only - Cross-Sectional Studies

              

            Cui (2011); China [41]

            n=986; 6–18 yrs; 53%

            Screen time (SR,PR)

              

            +

            +

            0

            +

             

            Age, income, sex, residence, clustering

            +

            +

            Devis-Devis (2009); SpainE[42]

            n=323; 12–16 yrs; 46%

            TV time;

              

            0

                

            Not noted

            +

            +

            e-game time;

              

            +

            Mobile ph time (SR) (V,R)

              

            +

            Granich (2011); Aust. [43]

            n=298; 11–12 yrs; 49%

            Screen time (SR) (R)

              

            0

            +

            +/-

            +

            0

            Not included (NS) except for SES (school day), gender (weekend day); analysed by school/weekend day

            +

            +

            Hardy (2006); Aust. [44]

            n=343; 12–13 yrs; 50%

            TV time (SR) (R)

              

            +

            0

            0

            +

            +

            Not included (NS)

            +

            ++

            Hesketh (2007); Aust.A B D[45]

            n=895; grade 5 & 6; 46%

            TV Time (PR) (R)

              

            +

            +

            -

            +

             

            School clustering

            +

            +

            Hoyos Cillero (2011); Spain [46]

            n=503; 10–13 yrs; ~50%

            TV time;

              

            +F,0M

            0F,0M

            0F,-M

             

            0F,+M

            Child & parent BMI, parent ed.; school clustering; stratified by age, gender; analysed by week/weekend day

            +

            +

            Screen time (SR) (R)

             

            0F,0M

            0F,0M

            0F,0M

             

            0F,+M

            Hume (2010); The Netherlands [47]

            n=338; 12–15 yrs; 55%

            TV time (SR)

             

            0

             

            0

            0

             

            +

            School clustering

            +

            +

            Jago (2008); Europe [48]

            n=2670; grade 3 & 9; 49%

            TV time;

              

            0

            0

               

            Grade, gender, father & mother income, obesity; school clustering, country (overall); stratified by country

            +

            ++

            e-game time (SR)

             

            0

            0

            Norman (2005); USA [49]

            n=878; 11–15 yrs; 46%

            Sedentary time (SR) (R)

             

            0F,0M

              

            -F, 0M

            +F,0M

             

            Age, ethnicity, BMI, education; stratified by gender

            +

            +

            Patriarca (2009); Italy [50]

            n=987; 11–16 yrs; 50%

            TV Time;

              

            0

            0

            0

              

            Age, gender, no. of siblings, both parents in household, parent working activity, sport activity

            +

            ++

            Computer time;

             

            +

            +

            0

            e-game time (SR)

             

            0

            0

            -

            Ramirez (2011); USA [51]

            n=160; mean 14.6 yrs; 48%

            TV time;

               

            +

            -

              

            Not noted; analysed by SR/PR

            +

            +

            e-game time;

              

            +

            -

            Computer time (SR,PR) (R)

              

            0

            -

            Springer (2010); USA [52]

            n=734; grade 4; 50%

            TV time (SR)

               

            0

            -

             

            +

            Gender, ethnicity, age, language, data collection period, school clustering; analysed by week/weekend day

            +

            +

            van Sluijs (2010); Europe [53]

            n=2107; 9–10 & 14–15 yrs; 46 & 56%

            Sedentary time (Acc) (V)

              

            0

            0

              

            0

            Grade, sex; stratified by country

            ++

            ++

            van Zutphen (2007); Aust. [54]

            n=1926; 4–12 yrs; 49%

            TV time (PR)

              

            +

            +

            -

              

            Parent ed., income, SES, no. of adults & children

            +

            +

            Zabinski (2007); USAC[55]

            n=878; 11–15 yrs; 48%

            Sedentary time (SR)

             

            -

              

            -

            0

             

            Not noted

            +

            +

            Sedentary Outcome Only - Longitudinal Studies

            Te Velde (2011); The NetherlandsB[56]

            n=12654; 11–17 yrs; 54%

            TV time (SR) (R)

               

            +

            -

             

            +

            Age, sex, school level (SES), ethnicity

            ++

            ++

            Willoughby (2008); Canada [57]

            n=1591; grade 9 & 10; 51%

            e-game use;

              

            0

                

            Parent ed., baseline value of outcome, gender

            +

            +

            Internet use (SR)

            0

            Longitudinal studies include age at baseline; E-games include electronic & computer games; Computer includes computer and internet use; All analysis at highest multivariate level unless otherwise noted; Significance at p<0.05 unless otherwise noted; M (male) & F (female) entered separately where stratified as such; For studies with multiple groups or time specific outcomes at least half of analysis must show an association in the given direction (‘+’ or ‘-‘) with an independent variable; Adjustments listed as stated in paper; SR self report, PR parent report, Acc accelerometer, V validity reported, R reliability reported, NS potential confounders not included in final analysis as found to be non-significant, SES socioeconomic status, BMI body mass index, A bivariate analysis, B mediation analysis, C cluster analysis, D significance p<0.1, E SEM analysis.

            Table 2

            Summary of observational studies with physical activity outcomes only

            Author (Year); Country

            Sample characteristics (Number, Age, % Male)

            Outcome variables

            Home physical and social environment independent variables

            Adjustments

            Internal validity

            External validity

            House & yard

            PA equipment

            Media equipment

            BR media equipment

            Family rules

            Family support

            Family behaviour

            Physical Activity Outcome Only - Cross-Sectional Studies

            Aarts (2010); The Netherlands [58]

            n=4297; 7–9 yrs, 10–12 yrs; M/F

            Outdoor Play (PR)

            +F,+M

             

            0F,0M

            +F,+M

            0F,0M

              

            Parent ed., school clustering; stratified by age, gender

            +

            +

            Erwin (2007); USA A B D[59]

            n=47; 6–13 yrs; 70%

            PA level (SR)

             

            0

            0

                

            None

            -

            -

            Haerens (2009); Belguim [60]

            n=62; grade 7 & 8; 19%

            MVPA time (Acc) (V,R)

             

            0

            0

              

            0

             

            Age, SES, gender

            +

            +

            Kerr (2008); USA [61]

            n=839; 11–15 yrs; 42%

            MVPA level (SR) (V)

             

            +F,0M

                

            0F,0M

            Age, ethnicity, parent ed., parent PA; stratified by gender

            +

            -

            Li (2006); China [62]

            n=1787; 11–17 yrs; 50%

            Inactivity (SR)

            0F,0M

             

            0F,0M

             

            0F,0M

            0F,-M

             

            Clustering; stratified by gender

            +

            ++

            Maddison (2009); NZC[63]

            n=110; 12–17 yrs; 57%

            MVPA time (Acc);

             

            0

                 

            Not noted

            +

            -

            MVPA time (SR) (V)

            +

            McMinn (2011); England [64]

            n=2071; 9–10 yrs; 48%

            PA counts (Acc)

            0

             

            0

              

            +

             

            Sex, age quartiles, mth of measurement, ethnicity, school clustering

            ++

            ++

            Page (2010); UK [65]

            n=1300; 10–11 yrs; 50%

            Outdoor play (SR)

            0F,0M

                  

            Daylight, neighbourhood deprivation, pubertal stage, BMI; stratified by gender

            +

            +

            Ridgers (2010); UK [66]

            n=110; 9–10 yrs; 41%

            MVPA time (Acc) (V,R)

             

            0

            -

                

            School clustering; analysed by week/weekend day time

            +

            +

            Spinks (2006); Aust. [67]

            n=518; 5–12 yrs; 54%

            Inactivity (PR)

             

            0

                 

            School clustering, gender, age, maternal ed., school transport, organised activity, family size, TV/computer use

            +

            +

            Trang (2009); Vietnam [68]

            n=2660; 11–16 yrs; 50%

            Inactivity (SR) (V)

            0F,-M

             

            0F,0M

             

            0F,0M

            0F,0M

             

            Clustering; sample weighted; stratified by gender

            ++

            ++

            Veitch (2010); Aust. [69]

            n=187; 8–9 yrs; 53%

            Outdoor play (PR) (R)

            0

                

            0

             

            Not noted; analysed by week/weekend day

            +

            +

            Wong (2010); Hong Kong [70]

            n=29,139; mean 14.5/6 yrs; 44%

            MVPA time (SR) (V,R)

              

            +/-F,-M

                

            School clustering, age, family affluence, parent ed.; stratified by sex

            ++

            ++

            Physical Activity Outcome Only – Longitudinal Studies

            Crawford (2010); Aust. [71]

            n=301; 10–12 yrs; 46%

            MVPA time (Acc) (V)

             

            0F,0M

            0F,0M

            0F,0M

            +F,0M

            +F,0M

            0F,+M

            School clustering, baseline age, average zBMI; analysed by sex

            ++

            ++

            Wilson (2011); USA [72]

            n=198; grade 6; 47.5%

            MVPA time (Acc)

             

            0

              

            0

            +

             

            Baseline MVPA & BMI, free lunch, ethnicity, parent ed., gender, intervention, school clustering

            ++

            ++

            Longitudinal studies include age at baseline; MVPA moderate to vigorous physical activity; Inactivity defined as insufficient MVPA; All analysis at highest multivariate level unless otherwise noted; Significance at p<0.05 unless otherwise noted; M (male) & F (female) entered separately where stratified as such; For studies with multiple groups or time specific outcomes at least half of analysis must show an association in the given direction (‘+’ or ‘-‘) with an independent variable; Adjustments listed as stated in paper; SR self report, PR parent report, Acc accelerometer, V validity reported, R reliability reported, SES socioeconomic status, BMI body mass index, A bivariate analysis, B significance p<0.01; C SEM analysis; D independent measure home environment summary including both physical activity and media equipment.

            Table 3

            Summary of observational studies with sedentary behaviour and physical activity outcomes

            Author (Year), Country

            Sample characteristics (Number, Age, % Male)

            Outcome variables

            Home physical and social environment independent variables

            Adjustments

            Internal validity

            External validity

               

            House & yard

            PA equipment

            Media equipment

            BR media equipment

            Family rules

            Family support

            Family behaviour

               

            Sedentary and Physical Activity Outcome - Cross-Sectional Studies

            Hume (2005); Aust.A B[73]

            n=127; 10 yrs, 52%

            Sedentary time;

             

            0F,0M

            0F,0M

            0F,0M

               

            Not included (NS); stratified by sex

            +

            +

              

            LPA;

             

            0F,0M

            0F,0M

            0F,0M

                  
              

            MPA (Acc) (V, R)

             

            0F,0M

            0F,0M

            0F,+M

                  

            Roemmich (2007); USA [74]

            n=88; 8–12 yrs; 50%

            TV time (SR & PR);

              

            +

                

            Age, SES, % overweight, Acc wear time (PA), gender

            +

            +

              

            PA counts;

              

            0

                   
              

            MVPA time (Acc) (V)

              

            0

                   

            Rosenberg (2010); USA [75]

            n=189; 12–18 yrs; 49% n=116; 5–11 yrs; 48%

            TV time;

             

            -

            +

            +

               

            Age, gender, race/ethnicity, household income, no. of children; stratified by age; analysed by PR/SR

            +

            +

              

            Sedentary time (SR & PR);

             

            0

            +

            +

                  
              

            MVPA time (SR & PR) (V)

             

            +

            0

            0

                  

            Salmon (2005); Aust. [76]

            n=878; 10–12 yrs; M/F

            TV Time (PR) (V,R);

              

            0F,0M

            0F,0M

            -F,-M

            0F,+M

            +F,+M

            Maternal ed., school clustering, weight (girls TV model); stratified by gender

            ++

            ++

              

            PA counts (low) (Acc) (V)

              

            0F,+/-M

            0F,0M

            -F,+M

            +F,0M

            +F,+M

               

            Sirard (2010); USAC[77]

            n=575; 10–17 yrs; 49%

            Sedentary time (Acc) (V,R);

             

            -

            +

            0

               

            Gender, age, ethnicity, parent ed., pubertal status, people in home, parent BMI, mth of data collection, free lunch, study cohort, school clustering; stratified by gender (screen time)

            +

            +

              

            Screen time (SR);

             

            -F,0M

            +F,0M

            0F,0M

                  
              

            MVPA time (Acc) (V)

             

            +

            0

            0

                  

            Sedentary and Physical Activity Outcome - Longitudinal Studies

            Delmas (2007); France [78]

            n=379, 12 yrs; 51%

            TV time;

               

            0F,+M

               

            School clustering, sexual maturity, SES; stratified by gender

            ++

            +

              

            Reading (SR) (V,R);

               

            -F,-M

                  
              

            Free & Club PA (SR) (V)

               

            0F,0M

                  

            Longitudinal studies include age at baseline; PA physical activity, LPA light physical activity, MPA moderate physical activity, MVPA moderate to vigorous physical activity; All analysis at highest multivariate level unless otherwise noted; Significance at p<0.05 unless otherwise noted; M (male) & F (female) entered separately where stratified as such; For studies with multiple groups or time specific outcomes at least half of analysis must show an association in the given direction (‘+’ or ‘-‘) with an independent variable; Adjustments listed as stated in paper; SR self report, PR parent report, Acc accelerometer, V validity reported, R reliability reported, NS potential confounders not included in final analysis as found to be non-significant, SES socioeconomic status, BMI body mass index, A bivariate analysis; B independent measures taken from map drawn by sample; C PA equipment measure also includes physical activity to media equipment ratio.

            Results

            Thirty-eight observational studies and 11 experimental studies were included in the final review (Figure 1). Most studies were conducted in high income countries including the USA [49, 51, 52, 55, 59, 61, 72, 74],[75, 77, 7983], Australia [4345, 54, 67, 69, 71, 73, 76], UK [6466, 84], New Zealand [63, 8587] and The Netherlands [47, 56, 58, 88]. Other countries contributing studies included China [41, 62], Spain [42, 46], Canada [57, 89], Italy [50], Belgium [60], Vietnam [68], Hong Kong [70] and France [78]. Two studies included multiple European countries [48, 53].

            Observational studies

            Thirty-eight observational studies were identified including 33 cross-sectional and 5 longitudinal studies. Due to the low number of longitudinal studies, observational studies were analysed as one group. However, where applicable, the results of longitudinal studies are also reported separately to differentiate this stronger class of evidence. Nine studies scored the highest internal validity [53, 56, 64, 68, 7072, 76, 78] and twelve scored the highest external validity [44, 48, 50, 53, 56, 62, 64, 68],[7072, 76].

            Studies investigated a variety of outcomes with 17 measuring sedentary outcomes (Table 1), 15 measuring PA outcomes (Table 2), and six measuring both (Table 3). In studies with sedentary outcomes, the most common was TV time (15 studies), followed by sedentary time (6 studies), electronic game use (5 studies), screen time (4 studies), computer/internet use (3 studies), mobile phone use (1 study) and reading (1 study). Two studies used accelerometers only [53, 73] and one study used accelerometers with self-report to capture sedentary outcomes [77]. The remainder of studies used either self-report (13 studies [4244, 4650, 52, 5557, 78]), parent report (3 studies [45, 54, 76]) or both (4 studies [41, 51, 74, 75]).

            PA outcomes included MVPA (11 studies), outdoor/free play (4 studies), average activity level (3 studies), inactivity (3 studies), moderate PA (1 study) and light PA (1 study). Ten studies used accelerometers [60, 63, 64, 66, 7174, 76, 77], nine used self-report [59, 6163, 65, 68, 70, 75, 78] and four used parental report [58, 67, 69, 75]. Two incorporated more than one data collection method [63, 75].

            The home physical environment

            Measures of the home physical environment included media equipment in the home (25 studies), media equipment in the child’s bedroom (20 studies), PA equipment (14 studies) and the parameters of the house and yard (6 studies). Two studies employed a home environment summary including both PA and media equipment [59, 77]. Home physical environmental measures were collected via self-report in 19 studies [4244, 47, 48, 50, 52, 53, 56, 57],[59, 60, 6366, 70, 73, 78], parental report in 14 studies [45, 49, 54, 55, 58, 61, 62, 6769],[71, 72, 76, 77] and five studies included both [41, 46, 51, 74, 75]. One study used an inventory implemented by parents [77] and no studies used objective measures of the home physical environment. Five studies reported the validity and reliability of the home physical environmental measure, ten reported reliability only and two reported validity only.

            Media equipment within the home was positively associated with children’s sedentary behaviours in 10 of 16 studies [41, 42, 4446, 50, 54, 74, 75, 77]. The one longitudinal study that investigated this relationship found no association between computers in the home and e-game or internet use [57]. For bedroom media equipment, nine of 18 studies found a positive association with sedentary behaviours [41, 43, 45, 50, 51, 54, 56, 75],[78], including both longitudinal studies that investigated TV time [56, 78]. One of these longitudinal studies also found an inverse relationship between a bedroom TV and reading [78]. There were limited and inconsistent associations between media equipment in the home and PA outcomes. Three of 14 studies found negative associations and two of these also found positive associations for different equipment measures [66, 70, 76]. Two of seven studies of bedroom media equipment found a positive association with PA [58, 73]. The two longitudinal studies in this group showed no association between media equipment and PA [71, 78].

            PA equipment was positively associated with PA outcomes in four of eleven studies [61, 63, 75, 77], with no association found in the two longitudinal studies [71, 72]. On the other hand, PA equipment was inversely associated with sedentary behaviours in three of six studies [55, 75, 77], although no longitudinal studies investigated this relationship. The least investigated category of the home physical environment was the house and yard. Two of six cross-sectional studies found that yard space was positively associated with a PA measure [58, 68] and one of these studies also found living in an apartment was negatively associated [58]. No studies investigating sedentary behaviours included a measure of size, space or design of the house and yard.

            Relationships between home physical and social environmental factors

            The majority of observational studies investigating the home physical environment also investigated home social environmental variables. Measures included family rules (19 studies), family social support (14 studies) and family behaviours (10 studies). Significant relationships between the home social environment and sedentary behaviours, and to a lesser extent PA, were evident after adjusting for home physical environmental factors. Some form of family social support was positively associated with sedentary behaviours in six of seven cross-sectional studies [41, 4345, 49, 76]. For PA outcomes five of eight studies showed an association in the expected direction. Social support for PA was positively associated with PA in four studies, including two longitudinal studies [62, 64, 71, 72], and playing e-games with parents was positively associated with low activity in one study [76]. Four of these studies scored the highest internal and external validity [64, 71, 72, 76]. Six of eight studies on electronic media use, with a family behaviour measure, found parental electronic media use positively associated with children’s use [44, 46, 47, 52, 56, 76]. This included all studies investigating TV time. Of the three studies measuring parental behaviour and PA outcomes, one cross-sectional study found parent e-game use positively associated with low activity [76], and one longitudinal study found parent PA participation positively associated with MVPA [71]. Both studies scored the highest internal and external validity. Of the six studies investigating rules and PA, these same two studies found an association. The longitudinal study found a positive relationship between rules restricting PA and MVPA in girls [71], and the cross-sectional study found mixed results with supervision of TV positively associated with low activity in boys and negatively associated in girls [76]. Electronic media rules were negatively associated with sedentary behaviours in 11 of 14 studies, including the one relevant longitudinal study [43, 45, 46, 4952, 5456, 76].

            In the 15 studies with sedentary outcomes that measured both physical and social environmental variables, 10 found associations with physical and social environmental measures [41, 4346, 50, 51, 5456]. Of these, only one study investigated an interaction between the home physical and social environmental factors reviewed, and results showed an inverse association between parental rules and TV viewing only when there was a TV in the bedroom [52]. In the 10 studies with PA outcomes that investigated the home physical and social environment, one study found associations with both [76]. No other moderating or mediating relationships between the reviewed physical and social environmental factors were explored.

            Experimental studies

            Experimental studies used one of two strategies to change the home physical environment: either introducing a television limiting device or an active video game (AVG).

            Television limiting device studies

            Five randomised control trials (RCT), ranging in duration from six weeks to 12 months, introduced a television limiting device (Table 4). Four studies scored the highest internal validity [7981, 89], while no studies scored the highest external validity. All studies measured screen based sedentary outcomes [7981, 85, 89], and four also measured PA and body composition outcomes [7981, 89]. Three studies of the highest internal validity found a significant decrease in TV viewing in the intervention group (47, 73 and 116 minutes per day) [80, 81, 89]. Two of these also showed improvement in body mass index (BMI) [81, 89]. The one study that rewarded children for PA with TV viewing tokens also increased PA by 65% [89]. Of the two studies that did not significantly change children’s sedentary behaviours, one found a significant decrease in overall household TV watching [79].
            Table 4

            Summary of experimental studies including TV limiting devices

            Author (Year); Country

            Sample characteristics (Number; Age; Sex; Other)

            Intervention description (Design; Duration; Characteristics)

            Measures

            Summary of key findings

            Adjustments

            Internal validity

            External validity

            French (2011); USA [79]

            n=75 adolescents randomised, n=87 HHs; 12–17 yrs; Sex not reported; HH TV ≥ 10 hrs per person per wk.

            Cluster RCT; 12 mths; Intervention - TV limiting devices, guidelines about food availability, 6 x group sessions, behavioural strategies, phone calls, 12 x home-based activities; Control - no intervention.

            SB - TV (SR); PA - MVPA (SR); Other - zBMI, dietary intake, eating behaviours, PA encouragement, PA with others in HH, TV is on.

            Significant decrease in reporting TV is on, and significant increase in consumption of fruit and veg in intervention compared to control. At HH level there was a significant decrease in TV watching, and a significant increase in PA encouragement, PA with others in HH compared to control.

            Gender, smoking, age, HH income, configuration, race, education; baseline values of outcomes; HH clustering.

            ++

            +

            Goldfield (2006); Canada [89]

            n=30; 8–12 yrs; 43% M; overweight or obese, TV/video games ≥15 hrs per wk, <30 mins MVPA per day.

            RCT; 8 wks; Intervention - wore PA monitor (open-loop feedback) and rewarded for PA (reinforcement) with TV access via token controlled TV limiting device; Control - wore a PA monitor (open-loop feedback only).

            SB - TV based, other (SR); PA - activity counts, MVPA, VPA (Acc); Other - height, weight, BMI, dietary intake.

            Significantly greater changes in total activity counts and MVPA, and reduction in TV based SB, fat intake, calories from snacks and snack intake in front of TV, and improvement in weight and BMI, compared to control. Reductions in weight, fat intake, calories from snacks, calories consumed in front of TV significantly correlated with reduction in TV based SB.

            Not noted.

            ++

            -

            Ni Mhurchu (2009); New Zealand [85]

            n=29; 9–12 yrs; 62% M; TV > 20 hrs per wk.

            RCT (Pilot); 6 wks; Intervention - electronic TV monitors, encouraged to restrict TV to 60 mins per day, ideas to reduce TV; Control - ideas to reduce TV.

            SB - TV, total screen time (SR); PA - steps (pedometer); Other - BMI, energy intake from snacks; Interviews.

            No significant differences. Decrease in weekly TV of 254 mins in intervention and 3 mins in control (NS). Total screen time decreased and steps increased slightly in both groups (NS). Mixed views on family acceptability of TV time monitors.

            Baseline values of outcomes.

            +

            +

            Robinson (2006); USA [80]

            n=181; mean 8.9 yrs; 54% M.

            Cluster RCT; 6 mths; Intervention - SMARTschool curriculum (18 lessons with TV Turn Off Challenge and goal to reduce to 7 hrs per wk), TV allowance device, parent newsletters; Control - no intervention.

            SB - TV, video, video game play (SR); Other - family member TV viewing; Interviews.

            Significant reduction in weekday TV, and weekday and weekend video game play compared to control. Significant reduction in mother, father and sibling TV viewing compared to control. Age, supervision, and prior TV and video game use moderated intervention effects.

            Baseline values of outcomes.

            ++

            +

            Todd (2008); USA [81]

            n=21; 8–11 yrs; M only; TV > 3.5 hrs or EM > 5.8 hrs per day.

            RCT; 20 wks; Intervention - seminar including goal setting, newsletters, TV allowance device, software to limit computer use, phone calls, recommendation to reduce EM to 90 mins per day; Control - no intervention.

            SB – EM use (SR); PA - steps (pedometer); Other - height, weight, BMI, % body fat, snacks and meals consumed with EM, dietary intake, bone mineral density.

            Significant treatment by time interaction for EM use and % body fat. Intervention decreased EM use from 153mins per day to 81 (10 wks) and 82 (20 wks) and control from 157 to 119 and 95 (adjusted difference of 73 mins at 20 weeks); Intervention decreased % body fat from 26.1 to 24.6 (20 wks) and control increased from 27.7 to 28.0. Significant reduction in snacks and meals consumed with EM, compared to control.

            Organised activity, electronic media access.

            ++

            -

            M male, HH household, SB sedentary behaviour, PA physical activity, RCT randomised control trial, MVPA moderate to vigorous physical activity, NS non-significant; n= is number in analysis unless noted; BMI body mass index, EM electronic media, Acc accelerometer, SR self reported; Measures column includes outcomes and variables used in further analysis (excluding adjustment variables); Significance at p<0.05 (outcomes not reported or listed in table as non-significant if p > 0.05); Adjustments listed as stated in paper.

            Active video gaming studies

            Of the six experimental studies that introduced an AVG into the home, four were RCTs (Table 5). Two RCTs scored the highest internal validity [84, 86], while no studies scored the highest external validity. Study durations ranged between 12 weeks and six months. Five of six studies collected outcome measures mid-intervention. Of the three RCTs that compared an intervention group to a play as usual control group: one found an increase in AVG play of 57 minutes per day at mid-intervention [84]; one found an increase in AVG play of 10 minutes per day and improvement in BMI post-intervention [86]; and one found an average difference in sedentary video gaming of 52 minutes per day, an increase in PA at mid-intervention and improvement in waist circumference post-intervention [87]; Two studies found a significant decrease in AVG play between the first and second half of the intervention [83, 84], with another two showing non-significant decreases [82, 88].
            Table 5

            Summary of experimental studies including active video games

            Author (Year); Country

            Sample characteristics (Number; Age; Sex; Other)

            Intervention description (Design; Duration; Characteristics)

            Measures

            Summary of key findings

            Adjustments

            Internal validity

            External validity

            Chin A Paw (2008); The Netherlands [88]

            n=16; 9–12 yrs; 14% M; low fitness.

            RCT (Pilot); 12 wks; Multiplayer intervention - Interactive Dance Simulation Video Game (IDSVG) for home use, 60 min weekly group class; Home intervention - IDSVG for home use only.

            PA - ISDVG play (SR); Other - focus groups.

            Multiplayer group averaged 901 mins ISDVG play and home group 376 mins (NS); Median play decreased from 228 mins in first 6 weeks to 0 min in second 6 weeks for home group, and increased from 475 min to 601 min in multiplayer group (NS). Significantly lower drop out in multiplayer group (15%) compared to home group (64%); Technical difficulties, need for computer and space, dull music and becoming bored were barriers.

            Not noted.

            +

            -

            Graves (2010); England [84]

            n=42; 8–10 yrs; %M not reported.

            RCT; 12 wks; Intervention - video games linked to jOG device that required stepping; Control - video game play as usual.

            PA - Step powered video gaming, AVG play, total video gaming (SR), steps, CPM, total PA (Acc); SB - sedentary video gaming, TV, productive behaviours, leisure behaviours (SR), sedentary (Acc); Other - stature, body mass, BMI, maturity offset, subtotal body fat, trunk body fat.

            Significant increase in AVG play compared to control at 6 weeks; Step powered video gaming was significantly higher at week 6 than 12 in intervention group.

            Gender; baseline values of outcomes; change in maturity offset (some).

            ++

            +

            Maddison (2011); New Zealand [86]

            n=322; 10–14 yrs; 73% M; overweight/ obese, video games ≥ 2 hrs per wk.

            RCT; 24 wks; Intervention - AVG supplied, encouraged to do 60 mins PA per day; Control - video game play as usual.

            PA - AVG play (SR), MVPA (Acc); SB - sedentary video gaming (SR); Other - weight, BMI, zBMI, total body fat, % body fat, waist circumference, energy intake from snacks, fitness.

            Significant treatment effect on zBMI, BMI, % body fat, total body fat, and increase in active video game time compared to control.

            Age, sex, ethnicity; baseline values of outcomes.

            ++

            +

            Madsen (2007); USA [82]

            n=30A; 9–18 yrs; 40% M; obese.

            Pre/post design; 6 mths; Intervention - DDR game, instructed to use 30 min x 5 days a wk, biweekly phone calls; No control group.

            PA – Dance Dance Revolution (DDR) use (SR), energy expenditure (memory card); Other - BMI; Interviews.

            No significant effects. 12 children used DDR at least twice a week in first 3 months, and only 2 in second 3 months. Family stressors and boredom were barriers.

            Baseline zBMI.

            -

            -

            Ni Mhurchu (2008); New Zealand [87]

            n=20; 10–14 yrs; 40% M.

            RCT (Pilot Study); 12 wks; Intervention - AVG supplied, instructed to substitute for regular video games; Control - video game play as usual.

            PA - AVG time, total video gaming (SR), CPM (Acc), MVPA (SR); SB - inactive video gaming (SR); Other - BMI, waist circumference.

            Average time in inactive video gaming was significantly lower compared to control. Objective PA (CPM) (6 wks) significantly higher and waist circumference (12 wks) significantly improved compared to control. Average total video game time was lower (54 vs 98 mins per day) compared to control (NS).

            Sex; baseline values of outcomes.

            +

            +

            Owens (2011); USA [83]

            n=12 children, n=8 families; 8–13 yrs; 50% M.

            Pre/post design; 3 mths; Intervention - Wii Fit, no instruction; No control group.

            PA - PA (Acc), Wii Fit use (console memory); Other - height, weight, %body fat, BMI, balance, muscular fitness, aerobic fitness, flexibility.

            12 min average Wii Fit use per HH per day, which decreased significantly from first to second 6 wks (21.5 to 3.9 mins per day). No significant pre-post changes in children except height and V02.

            Not noted.

            +

            -

            M male, HH household, SB sedentary behaviours, PA physical activity, RCT randomised control trial, MVPA moderate to vigorous physical activity, NS non-significant; n= is number in analysis unless noted; BMI body mass index, Acc accelerometer, SR self reported, CPM counts per minute; Measures column includes outcomes and variables used in further analysis (excluding adjustment variables); Significance at p<0.05 (outcomes not reported or listed in table as non-significant if p > 0.05); Adjustments listed as stated in paper; A n =26 at 3 mths, 21 at 6 mths, 12 with DDR use diary, 7 had memory card.

            Discussion

            The purpose of this paper was to review the influence of the home physical environment on children’s PA and sedentary behaviour. Results showed that media equipment was positively associated with screen based sedentary behaviours and PA equipment was unrelated to PA, reinforcing results of earlier reviews. Several previously unreviewed relationships were summarised, highlighting an inverse relationship between PA equipment and sedentary behaviour in half of studies. Interventions that changed the home environment by introducing TV limiting devices reduced TV time. The social environment, in particular parents, played an important role in influencing children’s sedentary behaviour and PA even in the presence of home physical environmental factors. The field is limited by the lack of objective assessment and no investigation of the indoor home space beyond equipment. Additionally, there was a paucity of studies investigating objectively measured sedentary time and home context specific behaviours. This review extends previous knowledge by critically assessing and synthesising evidence from both experimental and observational studies. The paper identifies current evidence gaps and measurement issues, and generates future directions for research on children’s sedentary behaviour and PA within the home space.

            Research evidence and gaps

            The home - house and yard

            In the current review, investigation of the size, space and design of the house and yard was limited. Although, previous reviews of correlates of children’s physical activity have not addressed this relationship at all [14, 15, 28, 29]. Only six studies could be found that collected any measure of the house or yard and the presence of a garden was the only measure collected more than once. While one of three studies investigating outdoor play found that girls without a garden played outside less [58], our overall results are in contrast to the findings of several qualitative studies that have identified lack of yard space as a barrier to physical activity and active play [23, 24, 26]. This lack of association could have been influenced by the limited and categorical nature of environmental variables investigated, and outcome measures that were not specific to the home. With the majority of children’s MVPA occurring outside of the home [90, 91], and the majority of leisure time at home spent indoors and sedentary [33, 34], it would seem pertinent to investigate the influence of the house and yard on children’s sedentary behaviour independent of PA. Further investigation of the indoor home space may also be relevant for PA with a recent ecological momentary assessment study of 9–13 year olds in California finding that 30% of all leisure time PA occurred indoors at home and only 8% occurred in the yard at home [90]. To date there has been no exploration of the relationship between the house and yard and children’s sedentary behaviours or home context specific PA.

            The home – media equipment

            Observational studies showed a positive relationship between media equipment and children’s screen based sedentary behaviours. This extends the findings of earlier reviews that have located few or no studies investigating this relationship [13, 14] and concurs with a more recent review of sedentary behaviour correlates [16]. The review also considered media equipment and PA, a relationship not summarised by previous reviews [14, 15, 28, 29], and found the majority of studies showed no relationship.

            This review located three studies investigating media equipment and objectively measured sedentary time and, to our knowledge, is the first review to summarise this relationship. Findings on the influence of media equipment in the home were mixed and there was no association between bedroom media equipment and accelerometer measured sedentary time [53, 73, 77]. Even with limited evidence, these findings are curious given the associations between media equipment and screen based sedentary behaviour. This suggests that children with less media equipment at home may simply substitute one sedentary behaviour for another resulting in no discernible difference to overall sedentary time. This is consistent with qualitative findings that indicated children would consider both active and sedentary alternatives if screen viewing was limited [25]. Notably, the studies reviewed measured sedentary time across the entire day. This included sedentary time in school and other places outside the home, which may be less likely to be influenced by home media equipment.

            The home – physical activity equipment

            Overall, our results support previous conclusions of limited evidence for a relationship between PA equipment at home and children’s PA [14, 28, 29]. However, we also found that children with more PA equipment spent less time in sedentary behaviours in half of studies [55, 75, 77], a relationship not considered by previous reviews [13, 14, 16]. While this evidence is inconclusive, it does raise the possibility that PA equipment at home may decrease sedentary behaviours by prompting alternative light intensity activities rather than MVPA.

            Changing the home environment

            Changing the home physical environment has the potential to influence children’s sedentary behaviour and PA. This review found interventions that implemented a TV limiting device were successful in decreasing children’s screen based sedentary behaviour. Also, introducing an AVG to the home resulted in positive changes in AVG play, sedentary electronic game play, PA and/or body composition in some studies [84, 86, 87], although early changes did not always last. Interventions that showed the most promise in changing behaviour and/or body composition directed participants to substitute activities, such as active gaming for sedentary gaming, or to earn TV time by participating in PA [84, 87, 89]. However, the acceptability of these changes in the home was debatable, with the need for space, boredom and disruption of other family members cited [82, 85, 88]. Additionally, the long term effects of introducing an AVG or limiting TV viewing on other behaviours, including screen based sedentary behaviours, productive sedentary behaviours and PA, are unclear.

            Home physical and social environmental interactions

            The review reaffirms the important role that parents play in supporting, restricting and normalising children’s sedentary behaviours [13, 16]. In accordance with ecological frameworks, we found that the influence of social environmental factors in the presence of physical environmental factors was evident. Although, it should be noted that results relating to the home social environment are limited to studies that investigated both social and physical environmental factors. Children with parents who watched more TV and those in families with no electronic media rules, spent more time watching TV. Additionally, children who participated in sedentary behaviour with their parents spent more time in sedentary behaviour. Despite many studies based upon ecological models, few investigated relationships between physical and social environmental factors within the home space. Of those that did, one study found parental rules were only effective when there was a bedroom TV [52]. Parents largely dictate the arrangement of the home space and determine the equipment available to children at home. Family rules are of particular interest as they present an avenue for controlling the influence of the physical environment through not allowing screens in bedrooms and living areas or choosing not to purchase media equipment. They may also restrict or encourage the use of home space for active behaviours. Thus far few studies have explored these relationships.

            Measurement issues

            Other authors have called for behaviour specific measures of the environment and context specific measures of PA and sedentary behaviours in the investigation of environmental influences [19, 92, 93]. Our review affirms the need for increased specificity of research on the home environment. There was only one study with a home context specific PA outcome [69]. Also, while specific sedentary behaviours such as TV watching mostly occur at home, objectively measured sedentary time was accumulated across the entire day. Reinforcing the value of this approach, we found elements of the home physical environment were more consistently associated with sedentary behaviours, which are more likely to occur at home, than with PA outcomes.

            Studies of the neighbourhood built environment have used objective measures (audits and Geographic Information Systems (GIS)) as well as perceived measures (self-report) [22, 94] to assess the environment, and Global Positioning Systems (GPS) to track individuals’ movement [95]. This review found all but one study used surveys to measure the home environment, with the exception using an inventory that measured equipment density, availability and accessibility [77]. Supporting the case for more robust measurement, this study was the only one to find PA equipment, in this case equipment density, related to accelerometer measured MVPA. It also found the ratio of PA to media equipment was related to accelerometer measured sedentary time. While it is acknowledged that current GIS and GPS technologies provide limited utility indoors, other technologies combining indoor location and movement sensors may have potential, but are yet to be applied in this context [96].

            Technology available within homes is changing rapidly and this also has implications for measurement of home media. For example electronic gaming may now be active or sedentary and portable media devices can be used in different places within the home [97]. However, in this review, only two observational studies included these more recent leisure technologies [75, 77].

            Future research directions

            Future studies on the influence of the home physical environment on children’s sedentary behaviour and PA need to investigate home context specific outcomes. The investigation of objectively measured sedentary time at home is most important [98]. Sedentary time at home should also be categorised by the type of sedentary behaviour including screen based and other productive/non-productive behaviours, such as reading and homework. This will assist to clarify whether children who spend less time in screen based behaviours are overall less sedentary at home, or whether they do more of other non-screen sedentary behaviours [33]. For PA, time spent in objectively measured PA levels at home and activity behaviours that occur specifically at home such as active play, AVG play and household chores are most relevant for future research.

            Investigation of the home physical environment lacks objective assessment and is limited, except for equipment. Future research on the indoor and outdoor home environment should, where applicable, adopt approaches used to measure the outdoor built environment. For example, GIS can provide objective measures of house and yard size [99] and audits provide scope to collect more objective and detailed data inside the home [77]. Additionally, just as GPS has been applied to locate individuals in outdoor environments [95], newer measurement technologies, such as indoor location and movement sensors, provide an avenue to track the location of individuals in indoor space [96]. Future research should draw on established approaches from other fields and closely monitor the development of new technologies that have measurement potential within the home.

            Both social and physical environmental factors influence children’s sedentary behaviour and PA, yet how they interact within the home space remains unclear. Parents control many elements of the home physical environment. Future research should explore the relationships between parental behaviour, family rules, equipment and arrangement of the home space, to better understand how sedentary behaviour is influenced by the home environment and to inform the development of interventions.

            Further intervention studies are highly recommended. We found only two types of interventions that changed the home physical environment. TV limiting devices reduced TV viewing, however, it is unknown which behaviours replace TV viewing and whether this strategy is successful in the longer term. Similarly, introducing an AVG showed promise, but any effects seemed to decay quickly. Interventions are required to determine the longer term effects of introducing TV limiting devices and AVGs on activity levels, and any unintended consequences on other physical activities and sedentary gaming. Other strategies such as changing the location of media equipment within the home, reconfiguring indoor spaces and substituting sedentary behaviours with active alternatives are lacking and should be explored. The key challenge for future research is to find acceptable active alternatives to traditionally sedentary behaviours within the home space.

            Strengths and limitations of the review

            This review included the best available evidence from both observational and intervention studies, identifying a larger number of studies with relevant home physical environmental variables than previous reviews. However, there are some limitations to the process and scope of this review. Firstly, some studies may have been missed due to the nature of the search terms and there may be some publication bias to studies with significant results. Secondly, independent and outcome measures were pooled into categories which were useful for summarising evidence, but did not differentiate between very specific environmental measures. For example, the home media equipment category included presence of a TV, presence of a computer, density of media equipment and number of TVs in the home. Thirdly, the summary of the home social environment in isolation should be interpreted with caution as it was limited to papers that also included home physical environmental factors and only the most common social home environmental factors were investigated. Also, individual factors were not included in the review. Finally, the pre-adolescent age group was identified as particularly relevant for investigation, although we acknowledge that this age group encompasses both children and adolescents as defined in previous reviews, and may limit comparability.

            Conclusion

            This review found that both physical and social environmental factors operating within the home space are important influences on children’s sedentary behaviour and PA. Media equipment is associated with children’s screen based sedentary behaviours. Changing the physical environment shows promise for reducing the sedentary nature of homes, although further interventions are needed to understand the broader impact of changes. Considering the substantial amount of time children spend at home, there has been little investigation of how the physical parameters of the home space may constrain or support children’s sedentary behaviour and PA. Future studies should ideally include objective measures of the home and prioritise investigating environmental influences within the home space on objectively measured sedentary time at home and home context specific behaviours.

            Declarations

            Acknowledgements

            CM is supported by a Healthway Health Promotion Research Scholarship (#21357).

            SF is supported by a Healthway Health Promotion Research Fellowship (#21363).

            The authors would like to acknowledge the University of Western Australia for providing resources to enable the completion of the study.

            Authors’ Affiliations

            (1)
            School of Sport Science, Exercise and Health, University of Western Australia
            (2)
            Applied Sports Technology Exercise Medicine Research Centre, School of Engineering, Swansea University
            (3)
            Centre for Built Environment and Health, School of Population Health, University of Western Australia

            References

            1. Owen N, Healy GN, Matthews CE, Dunstan DW: Too much sitting: the population health science of sedentary behavior. Exerc Sport Sci Rev. 2010, 38: 105-113. 10.1097/JES.0b013e3181e373a2.View Article
            2. Carver A, Timperio A, Crawford D: Playing it safe: the influence of neighbourhood safety on children's physical activity - a review. Health Place. 2008, 14: 217-227. 10.1016/j.healthplace.2007.06.004.View Article
            3. Karsten L: It all used to be better? Different generations on continuity and change in urban children's daily use of space. Child Geogr. 2005, 3: 275-290. 10.1080/14733280500352912.View Article
            4. Hallal PC, Victora CG, Azevedo MR, Wells JCK: Adolescent physical activity and health. Sports Med. 2006, 36: 1019-1030. 10.2165/00007256-200636120-00003.View Article
            5. Jiménez-Pavón D, Kelly J, Reilly JJ: Associations between objectively measured habitual physical activity and adiposity in children and adolescents: systematic review. Int J Pediatr Obes. 2010, 5: 3-18. 10.3109/17477160903067601.View Article
            6. Andersen LB, Harro M, Sardinha LB, Froberg K, Ekelund U, Brage S, Anderssen SA: Physical activity and clustered cardiovascular risk in children: a cross-sectional study (The European Youth Heart Study). Lancet. 2006, 368: 299-304. 10.1016/S0140-6736(06)69075-2.View Article
            7. Marshall SJ, Biddle SJH, Gorely T, Cameron N, Murdey I: Relationships between media use, body fatness and physical activity in children and youth: a meta-analysis. Int J Obes. 2004, 28: 1238-1246. 10.1038/sj.ijo.0802706.View Article
            8. Tremblay MS, LeBlanc AG, Kho ME, Saunders TJ, Larouche RC, Colley R, Goldfield G, Gorber SC: Systematic review of sedentary behaviour and health indicators in school-aged children and youth. Int J Behav Nutr Phys Act. 2011, 8: 98-10.1186/1479-5868-8-98.View Article
            9. Matthews CE, Chen KY, Freedson PS, Buchowski MS, Beech BM, Pate RR, Troiano RP: Amount of time spent in sedentary behaviors in the United States, 2003–2004. Am J Epidemiol. 2008, 167: 875-881. 10.1093/aje/kwm390.View Article
            10. Troiano RP, Berrigan D, Dodd KW, Masse LC, Tilert T, McDowell M: Physical activity in the United States measured by accelerometer. Med Sci Sports Exerc. 2008, 40: 181-188.View Article
            11. Tremblay MS, Colley RC, Saunders TJ, Healy GN, Owen N: Physiological and health implications of a sedentary lifestyle. Appl Physiol Nutr Metab. 2010, 35: 725-740. 10.1139/H10-079.View Article
            12. Ridley K, Ainsworth BE, Olds TS: Development of a compendium of energy expenditures for youth. Int J Behav Nutr Phys Act. 2008, 5: 45-10.1186/1479-5868-5-45.View Article
            13. Gorely T, Marshall SJ, Biddle SJH: Couch kids: correlates of television viewing among youth. Int J Behav Med. 2004, 11: 152-163. 10.1207/s15327558ijbm1103_4.View Article
            14. van der Horst K, Chin A Paw MJM, Twisk JWR, van Mechelen W: A brief review on correlates of physical activity and sedentariness in youth. Med Sci Sports Exerc. 2007, 39: 1241-1250. 10.1249/mss.0b013e318059bf35.View Article
            15. Sallis JF, Prochaska JJ, Taylor WC: A review of correlates of physical activity of children and adolescents. Med Sci Sports Exerc. 2000, 32: 963-975.View Article
            16. Pate RR, Mitchell JA, Byun W, Dowda M: Sedentary behaviour in youth. Br J Sports Med. 2011, 45: 906-913. 10.1136/bjsports-2011-090192.View Article
            17. Stokols D: Establishing and maintaining healthy environments: toward a social ecology of health promotion. Am Psychol. 1992, 47: 6-22.View Article
            18. Sallis JF, Owen N, Fisher EB: Ecological Models of Health Behaviour. Health Behaviour and Health Education: Theory, Research and Practice. Edited by: Glanz K, Rimer BK, Viswanath K. 2008, San Francisco: Jossey-Bass, 465-485. 4
            19. Giles-Corti B, Timperio AF, Bull FC, Pikora T: Understanding physical activity environmental correlates: increased specificity for ecological models. Exerc Sport Sci Rev. 2005, 33: 175-181. 10.1097/00003677-200510000-00005.View Article
            20. Edwardson CL, Gorely T: Parental influences on different types and intensities of physical activity in youth: a systematic review. Psychol Sport Exerc. 2010, 11: 522-535. 10.1016/j.psychsport.2010.05.001.View Article
            21. Carver A, Timperio AF, Crawford DA: Neighborhood road environments and physical activity among youth: the CLAN study. J Urban Health. 2008, 85: 532-544. 10.1007/s11524-008-9284-9.View Article
            22. Ding D, Sallis JF, Kerr J, Lee S, Rosenberg DE: Neighborhood environment and physical activity among youth - a review. Am J Prev Med. 2011, 41: 442-455. 10.1016/j.amepre.2011.06.036.View Article
            23. Veitch J, Bagley S, Ball K, Salmon J: Where do children usually play? A qualitative study of parents' perceptions of influences on children's active free-play. Health Place. 2006, 12: 383-393. 10.1016/j.healthplace.2005.02.009.View Article
            24. Hesketh K, Waters E, Green J, Salmon L, Williams J: Healthy eating, activity and obesity prevention: a qualitative study of parent and child perceptions in Australia. Health Promotion Int. 2005, 20: 19-26. 10.1093/heapro/dah503.View Article
            25. Sebire SJ, Jago R, Gorely T, Hoyos Cillero I, Biddle SJH: “If there wasn't the technology then I would probably be out everyday”: a qualitative study of children's strategies to reduce their screen viewing. Prev Med. 2011, 53: 303-308. 10.1016/j.ypmed.2011.08.019.View Article
            26. Jago R, Thompson JL, Page AS, Brockman R, Cartwright K, Fox KR: Licence to be active: parental concerns and 10-11-year-old children's ability to be independently physically active. J Public Health. 2009, 31: 472-477. 10.1093/pubmed/fdp053.View Article
            27. Granich J, Rosenberg M, Knuiman M, Timperio AF: Understanding children's sedentary behaviour: a qualitative study of the family home environment. Health Educ Res. 2010, 25: 199-210. 10.1093/her/cyn025.View Article
            28. Davison KK, Lawson CT: Do attributes in the physical environment influence children's physical activity? A review of the literature. Int J Behav Nutr Phys Act. 2006, 3: 19-10.1186/1479-5868-3-19.View Article
            29. Ferreira I, van der Horst K, Wendel-Vos W, Kremers S, van Lenthe FJ, Brug J: Environmental correlates of physical activity in youth: a review and update. Obes Rev. 2007, 8: 129-154. 10.1111/j.1467-789X.2006.00264.x.View Article
            30. Australian Bureau of Statistics: Larger Dwellings, Smaller Households. 2007, Canberra: Commonwealth of Australia
            31. Roberts-Hughes R: The Case for Space: The Size of England’s New Homes. 2011, London: Royal Institute of British Architects
            32. Jones AP, Coombes EG, Griffin SJ, van Sluijs EMF: Environmental supportiveness for physical activity in English schoolchildren: a study using global positioning systems. Int J Behav Nutr Phys Act. 2009, 6: 42-10.1186/1479-5868-6-42.View Article
            33. Biddle SJH, Marshall SJ, Gorely T, Cameron N: Temporal and environmental patterns of sedentary and active behaviors during adolescents' leisure time. Int J Behav Med. 2009, 16: 278-286. 10.1007/s12529-008-9028-y.View Article
            34. Sener IN, Copperman RB, Pendyala RM, Bhat CR: An analysis of children's leisure activity engagement: examining the day of week, location, physical activity level, and fixity dimensions. Transportation. 2008, 35: 673-696. 10.1007/s11116-008-9173-9.View Article
            35. Thornburg HD: Is early adolescence really a stage of development?. Theory Into Pract. 1983, 22: 79-84. 10.1080/00405848309543043.View Article
            36. Nader PR, Bradley RH, Houts RM, McRitchie SL, O'Brien M: Moderate-to-vigorous physical activity from ages 9 to 15 years. JAMA. 2008, 300: 295-305. 10.1001/jama.300.3.295.View Article
            37. Brodersen NH, Steptoe A, Boniface DR, Wardle J: Trends in physical activity and sedentary behaviour in adolescence: ethnic and socioeconomic differences. Br J Sports Med. 2007, 41: 140-144. 10.1136/bjsm.2006.031138.View Article
            38. Rideout VJ, Foehr UG, Roberts DF: Generation M2: Media in the Lives of 8- to 18-Year-Olds. 2010, Menlo Park, California: Henry J. Kaiser Family Foundation
            39. Aeffect Inc: Review of Literature to Support Development of the Youth Media Campaign: Exploring How to Motivate Behavior Change Among Tweens in America. 2000, Lake Forest, Illinois: Department of Health and Human Services’ Centers for Disease Control and Prevention
            40. National Institute for Health and Clinical Excellence: Methods for the Development of NICE Public Health Guidance (second edition). 2009, London: National Health Service
            41. Cui Z, Hardy LL, Dibley MJ, Bauman A: Temporal trends and recent correlates in sedentary behaviours in Chinese children. Int J Behav Nutr Phys Act. 2011, 8: 93-10.1186/1479-5868-8-93.View Article
            42. Devis-Devis J, Peiro -Velert C, Beltran-Carrillo VJ, Tomas JM: Screen media time usage of 12–16 year-old Spanish school adolescents: effects of personal and socioeconomic factors, season and type of day. J Adolesc. 2009, 32: 213-231. 10.1016/j.adolescence.2008.04.004.View Article
            43. Granich J, Rosenberg M, Knuiman MW, Timperio A: Individual, social, and physical environment factors associated with electronic media use among children: sedentary behavior at home. J Phys Act Health. 2011, 8: 613-625.
            44. Hardy LL, Baur LA, Garnett SP, Crawford D, Campbell KJ, Shrewsbury VA, Cowell CT, Salmon J: Family and home correlates of television viewing in 12–13 year old adolescents: The Nepean Study. Int J Behav Nutr Phys Act. 2006, 3: 24-10.1186/1479-5868-3-24.View Article
            45. Hesketh K, Ball K, Crawford D, Campbell K, Salmon J: Mediators of the relationship between maternal education and children's TV viewing. Am J Prev Med. 2007, 33: 41-47. 10.1016/j.amepre.2007.02.039.View Article
            46. Hoyos Cillero I, Jago R: Sociodemographic and home environment predictors of screen viewing among Spanish school children. J Public Health. 2011, 33: 392-402. 10.1093/pubmed/fdq087.View Article
            47. Hume C, van der Horst K, Brug J, Salmon J, Oenema A: Understanding the correlates of adolescents' TV viewing: a social ecological approach. Int J Pediatr Obes. 2010, 5: 161-168. 10.3109/17477160903242550.View Article
            48. Jago R, Page A, Froberg K, Sardinha LB, Klasson-Heggebo L, Andersen LB: Screen-viewing and the home TV environment: The European Youth Heart Study. Prev Med. 2008, 47: 525-529. 10.1016/j.ypmed.2008.07.016.View Article
            49. Norman GJ, Schmid BA, Sallis JF, Calfas KJ, Patrick K: Psychosocial and environmental correlates of adolescent sedentary behaviors. Pediatrics. 2005, 116: 908-916. 10.1542/peds.2004-1814.View Article
            50. Patriarca A, Di Giuseppe G, Albano L, Marinelli P, Angelillo IF: Use of television, videogames, and computer among children and adolescents in Italy. BMC Public Health. 2009, 9: 139-10.1186/1471-2458-9-139.View Article
            51. Ramirez ER, Norman GJ, Rosenberg DE, Kerr J, Saelens BE, Durant N, Sallis JF: Adolescent screen time and rules to limit screen time in the home. J Adolesc Health. 2011, 48: 379-385. 10.1016/j.jadohealth.2010.07.013.View Article
            52. Springer AE, Kelder SH, Barroso CS, Drenner KL, Shegog R, Ranjit N, Hoelscher DM: Parental influences on television watching among children living on the Texas-Mexico border. Prev Med. 2010, 51: 112-117. 10.1016/j.ypmed.2010.05.013.View Article
            53. van Sluijs EMF, Page A, Ommundsen Y, Griffin SJ: Behavioural and social correlates of sedentary time in young people. Br J Sports Med. 2010, 44: 747-755. 10.1136/bjsm.2008.049783.View Article
            54. van Zutphen M, Bell AC, Kremer PJ, Swinburn BA: Association between the family environment and television viewing in Australian children. J Paediatr Child Health. 2007, 43: 458-463. 10.1111/j.1440-1754.2007.01111.x.View Article
            55. Zabinski MF, Norman GJ, Sallis JF, Calfas KJ, Patrick K: Patterns of sedentary behavior among adolescents. Health Psychol. 2007, 26: 113-120.View Article
            56. Te Velde SJ, van der Horst K, Oenema A, Timperio A, Crawford D, Brug J: Parental and home influences on adolescents' TV viewing: a mediation analysis. Int J Pediatr Obes. 2011, 6: 364-372. 10.3109/17477166.2010.490264.View Article
            57. Willoughby T: A short-term longitudinal study of internet and computer game use by adolescent boys and girls: prevalence, frequency of use, and psychosocial predictors. Dev Psychol. 2008, 44: 195-204.View Article
            58. Aarts MJ, Wendel-Vos W, van Oers HAM, van de Goor IAM, Schuit AJ: Environmental determinants of outdoor play in children - a large-scale cross-sectional study. Am J Prev Med. 2010, 39: 212-219. 10.1016/j.amepre.2010.05.008.View Article
            59. Erwin HE, Woods AM, Woods MK, Castelli DM: Children's environmental access in relation to motor competence, physical activity, and fitness. J Teach Phys Educ. 2007, 26: 404-415.
            60. Haerens L, Craeynest M, Deforche B, Maes L, Cardon G, De Bourdeaudhuij I: The contribution of home, neighbourhood and school environmental factors in explaining physical activity among adolescents. J Environ Public Health. 2009, 2009: 320372.View Article
            61. Kerr J, Norman GJ, Sallis JF, Patrick K: Exercise aids, neighborhood safety, and physical activity in adolescents and parents. Med Sci Sports Exerc. 2008, 40: 1244-1248. 10.1249/MSS.0b013e31816b8797.View Article
            62. Li M, Dibley MJ, Sibbritt D, Yan H: Factors associated with adolescents' physical inactivity in Xi'an City, China. Med Sci Sports Exerc. 2006, 38: 2075-2085. 10.1249/01.mss.0000233802.54529.87.View Article
            63. Maddison R, Hoorn SV, Jiang Y, Ni Mhurchu C, Exeter D, Dorey E, Bullen C, Utter J, Schaaf D, Turley M: The environment and physical activity: the influence of psychosocial, perceived and built environmental factors. Int J Behav Nutr Phys Act. 2009, 6: 19-10.1186/1479-5868-6-19.View Article
            64. McMinn AM, van Sluijs EMF, Nightingale CM, Griffin SJ, Cook DG, Owen CG, Rudnicka AR, Whincup PH: Family and home correlates of children's physical activity in a multi-ethnic population: the cross-sectional Child Heart and Health Study in England (CHASE). Int J Behav Nutr Phys Act. 2011, 8: 11-10.1186/1479-5868-8-11.View Article
            65. Page AS, Cooper AR, Griew P, Jago R: Independent mobility, perceptions of the built environment and children's participation in play, active travel and structured exercise and sport: The PEACH Project. Int J Behav Nutr Phys Act. 2010, 7: 17-10.1186/1479-5868-7-17.View Article
            66. Ridgers ND, Graves LEF, Foweather L, Stratton G: Examining influences on boy's and girls' physical activity patterns: The A-CLASS Project. Pediatr Exerc Sci. 2010, 22: 638-650.
            67. Spinks A, Macpherson A, Bain C, McClure R: Determinants of sufficient daily activity in Australian primary school children. J Paediatr Child Health. 2006, 42: 674-679. 10.1111/j.1440-1754.2006.00950.x.View Article
            68. Trang NHHD, Hong TK, Dibley MJ, Sibbritt DW: Factors associated with physical inactivity in adolescents in Ho Chi Minh City, Vietnam. Med Sci Sports Exerc. 2009, 41: 1374-1383. 10.1249/MSS.0b013e31819c0dd3.View Article
            69. Veitch J, Salmon J, Ball K: Individual, social and physical environmental correlates of children's active free-play: a cross-sectional study. Int J Behav Nutr Phys Act. 2010, 7: 11-10.1186/1479-5868-7-11.View Article
            70. Wong BYM, Cerin E, Ho SY, Mak KK, Lo WS, Lam TH: Adolescents' physical activity: competition between perceived neighborhood sport facilities and home media resources. Int J Pediatr Obes. 2010, 5: 169-176. 10.3109/17477160903159432.View Article
            71. Crawford D, Cleland V, Timperio A, Salmon J, Andrianopoulos N, Roberts R, Giles-Corti B, Baur L, Ball K: The longitudinal influence of home and neighbourhood environments on children's body mass index and physical activity over 5 years: The CLAN study. Int J Obes. 2010, 34: 1177-1187. 10.1038/ijo.2010.57.View Article
            72. Wilson DK, Lawman HG, Segal M, Chappell S: Neighborhood and parental supports for physical activity in minority adolescents. Am J Prev Med. 2011, 41: 399-406. 10.1016/j.amepre.2011.06.037.View Article
            73. Hume C, Salmon J, Ball K: Children's perceptions of their home and neighborhood environments, and their association with objectively measured physical activity: a qualitative and quantitative study. Health Educ Res. 2005, 20: 1-13.View Article
            74. Roemmich JN, Epstein LH, Raja S, Yin L: The neighborhood and home environments: disparate relationships with physical activity and sedentary behaviors in youth. Ann Behav Med. 2007, 33: 29-38.View Article
            75. Rosenberg DE, Sallis JF, Kerr J, Maher J, Norman GJ, Durant N, Harris SK, Saelens BE: Brief scales to assess physical activity and sedentary equipment in the home. Int J Behav Nutr Phys Act. 2010, 7: 10-10.1186/1479-5868-7-10.View Article
            76. Salmon J, Timperio A, Telford A, Carver A, Crawford D: Association of family environment with children's television viewing and with low level of physical activity. Obes Res. 2005, 13: 1939-1951. 10.1038/oby.2005.239.View Article
            77. Sirard JR, Laska MN, Patnode CD, Farbakhsh K, Lytle LA: Adolescent physical activity and screen time: associations with the physical home environment. Int J Behav Nutr Phys Act. 2010, 7: 82-10.1186/1479-5868-7-82.View Article
            78. Delmas C, Platat C, Schweitzer B, Wagner A, Oujaa M, Simon C: Association between television in bedroom and adiposity throughout adolescence. Obesity. 2007, 15: 2495-2503. 10.1038/oby.2007.296.View Article
            79. French SA, Gerlach AF, Mitchell NR, Hannan PJ, Welsh EM: Household obesity prevention: Take Action - a group-randomized trial. Obesity. 2011, 19: 2082-2088. 10.1038/oby.2010.328.View Article
            80. Robinson TN, Borzekowski DL: Effects of the SMART classroom curriculum to reduce child and family screen time. J Commun. 2006, 56: 1-26. 10.1111/j.1460-2466.2006.00001.x.View Article
            81. Todd MK, Reis-Bergan MJ, Sidman CL, Flohr JA, Jameson-Walker K, Spicer-Bartolau T, Wildeman K: Effect of a family-based intervention on electronic media use and body composition among boys aged 8—11 years: a pilot study. J Child Health Care. 2008, 12: 344-358. 10.1177/1367493508097404.View Article
            82. Madsen KA, Yen S, Wlasiuk L, Newman TB, Lustig R: Feasibility of a dance videogame to promote weight loss among overweight children and adolescents. Arch Pediatr Adolesc Med. 2007, 161: 105-107.View Article
            83. Owens SG, Garner JC, Loftin JM, van Blerk N, Ermin K: Changes in physical activity and fitness after 3 months of home Wii Fit use. J Strength Cond Res. 2011, 25: 3191-3197. 10.1519/JSC.0b013e3182132d55.View Article
            84. Graves LEF, Ridgers ND, Atkinson G, Stratton G: The effect of active video gaming on children's physical activity, behavior preferences and body composition. Pediatr Exerc Sci. 2010, 22: 535-546.
            85. Ni Mhurchu CN, Roberts V, Maddison R, Dorey E, Jiang Y, Jull A, Tin ST: Effect of electronic time monitors on children's television watching: pilot trial of a home-based intervention. Prev Med. 2009, 49: 413-417. 10.1016/j.ypmed.2009.09.003.View Article
            86. Maddison R, Foley L, Ni Mhurchu C, Jiang YN, Jull A, Prapavessis H, Hohepa M, Rodgers A: Effects of active video games on body composition: a randomized controlled trial. Am J Clin Nutr. 2011, 94: 156-163. 10.3945/ajcn.110.009142.View Article
            87. Ni Mhurchu C, Maddison R, Jiang Y, Jull A, Prapavessis H, Rodgers A: Couch potatoes to jumping beans: a pilot study of the effect of active video games on physical activity in children. Int J Behav Nutr Phys Act. 2008, 5: 8-10.1186/1479-5868-5-8.View Article
            88. Chin A Paw MJM, Jacobs WM, Vaessen EPG, Titze S, van Mechelen W: The motivation of children to play an active video game. J Sci Med Sport. 2008, 11: 163-166. 10.1016/j.jsams.2007.06.001.View Article
            89. Goldfield GS, Mallory R, Parker T, Cunningham T, Legg C, Lumb A, Parker K, Prud'homme D, Gaboury I, Adamo KB: Effects of open-loop feedback on physical activity and television viewing in overweight and obese children: a randomized, controlled trial. Pediatrics. 2006, 118: 157-166. 10.1542/peds.2005-3052.View Article
            90. Dunton GF, Kawabata K, Intille S, Wolch J, Pentz MA: Assessing the social and physical contexts of children's leisure-time physical activity: an ecological momentary assessment study. Am J Health Promot. 2012, 26: 135-142. 10.4278/ajhp.100211-QUAN-43.View Article
            91. Rainham DG, Bates CJ, Blanchard CM, Dummer TJ, Kirk SF, Shearer CL: Spatial classification of youth physical activity patterns. Am J Prev Med. 2012, 42: 87-96.View Article
            92. Biddle SJH, Atkin AJ, Cavill N, Foster C: Correlates of physical activity in youth: a review of quantitative systematic reviews. Int Rev Sport Exerc Psychol. 2011, 4: 25-49. 10.1080/1750984X.2010.548528.View Article
            93. Owen N, Sugiyama T, Eakin EE, Gardiner PA, Tremblay MS, Sallis JF: Adults' sedentary behavior: determinants and interventions. Am J Prev Med. 2011, 41: 189-196. 10.1016/j.amepre.2011.05.013.View Article
            94. Jago R, Baranowski T, Baranowski JC: Observed, GIS, and self-reported environmental features and adolescent physical activity. Am J Health Promot. 2006, 20: 422-428. 10.4278/0890-1171-20.6.422.View Article
            95. Krenn PJ, Titze S, Oja P, Jones A, Ogilvie D: Use of global positioning systems to study physical activity and the environment - a systematic review. Am J Prev Med. 2011, 41: 508-515. 10.1016/j.amepre.2011.06.046.View Article
            96. Zhu C, Sheng W: Motion- and location-based online human daily activity recognition. Pervasive Mob Comput. 2011, 7: 256-269. 10.1016/j.pmcj.2010.11.004.View Article
            97. Jago R, Sebire S, Gorely T, Hoyos Cillero I, Biddle SJH: "I'm on it 24/7 at the moment": a qualitative examination of multi-screen viewing behaviours among UK 10–11 year olds. Int J Behav Nutr Phys Act. 2011, 8: 85-10.1186/1479-5868-8-85.View Article
            98. Tandon PS, Zhou C, Sallis JF, Cain KL, Frank LD, Saelens BE: Home environment relationships with children's physical activity, sedentary time, and screen time by socioeconomic status. Int J Behav Nutr Phys Act. 2012, 9: 88-10.1186/1479-5868-9-88.View Article
            99. Hall T: Goodbye to the backyard? The minimisation of private open space in the Australian outer-suburban estate. Urban Pol Res. 2010, 28: 411-433. 10.1080/08111146.2010.496715.View Article

            Copyright

            © Maitland et al.; licensee BioMed Central Ltd. 2013

            This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://​creativecommons.​org/​licenses/​by/​2.​0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.