Systematic literature review of built environment effects on physical activity and active transport - an update and new findings on health equity.

BACKGROUND: Evidence is mounting to suggest a causal relationship between the built environment and people's physical activity behaviours, particularly active transport. The evidence base has been hindered to date by restricted consideration of cost and economic factors associated with built environment interventions, investigation of socioeconomic or ethnic differences in intervention effects, and an inability to isolate the effect of the built environment from other intervention types. The aims of this systematic review were to identify which environmental interventions increase physical activity in residents at the local level, and to build on the evidence base by considering intervention cost, and the differential effects of interventions by ethnicity and socioeconomic status. METHODS: A systematic database search was conducted in June 2015. Articles were eligible if they reported a quantitative empirical study (natural experiment or a prospective, retrospective, experimental, or longitudinal research) investigating the relationship between objectively measured built environment feature(s) and physical activity and/or travel behaviours in children or adults. Quality assessment was conducted and data on intervention cost and whether the effect of the built environment differed by ethnicity or socioeconomic status were extracted. RESULTS: Twenty-eight studies were included in the review. Findings showed a positive effect of walkability components, provision of quality parks and playgrounds, and installation of or improvements in active transport infrastructure on active transport, physical activity, and visits or use of settings. There was some indication that infrastructure improvements may predominantly benefit socioeconomically advantaged groups. Studies were commonly limited by selection bias and insufficient controlling for confounders. Heterogeneity in study design and reporting limited comparability across studies or any clear conclusions to be made regarding intervention cost. CONCLUSIONS: Improving neighbourhood walkability, quality of parks and playgrounds, and providing adequate active transport infrastructure is likely to generate positive impacts on activity in children and adults. The possibility that the benefits of infrastructure improvements may be inequitably distributed requires further investigation. Opportunities to improve the quality of evidence exist, including strategies to improve response rates and representativeness, use of valid and reliable measurement tools, cost-benefit analyses, and adequate controlling for confounders.

Road user behaviour changes following a self-explaining roads intervention.

The self-explaining roads (SER) approach uses road designs that evoke correct expectations and driving behaviours from road users to create a safe and user-friendly road network. Following the implementation of an SER process and retrofitting of local and collector roads in a suburb within Auckland City, lower speeds on local roads and less variation in speed on both local and collector roads were achieved, along with a closer match between actual and perceived safe speeds. Preliminary analyses of crash data shows that the project has resulted in a 30% reduction crash numbers and an 86% reduction in crash costs per annum, since the road changes were completed. In order to further understand the outcomes from this project, a study was carried out to measure the effects of the SER intervention on the activity and behaviour of all road users. Video was collected over nine separate days, at nine different locations, both before and after SER construction. Road user behaviour categories were developed for all potential road users at different location types and then used to code the video data. Following SER construction, on local roads there was a relatively higher proportion of pedestrians, less uniformity in vehicle lane keeping and less indicating by motorists along with less through traffic, reflecting a more informal/low speed local road environment. Pedestrians were less constrained on local roads following SER construction, possibly reflecting a perceptually safer and more user-friendly environment. These behaviours were not generally evident on collector roads, a trend also shown by the previous study of speed changes. Given that one of the objectives of SER is to match road user behaviour with functionally different road categories, the road user behaviour differences demonstrated on different road types within the SER trial area provides further reinforcement of a successful SER trial.

Using endemic road features to create self-explaining roads and reduce vehicle speeds.

This paper describes a project undertaken to establish a self-explaining roads (SER) design programme on existing streets in an urban area. The methodology focussed on developing a process to identify functional road categories and designs based on endemic road characteristics taken from functional exemplars in the study area. The study area was divided into two sections, one to receive SER treatments designed to maximise visual differences between road categories, and a matched control area to remain untreated for purposes of comparison. The SER design for local roads included increased landscaping and community islands to limit forward visibility, and removal of road markings to create a visually distinct road environment. In comparison, roads categorised as collectors received increased delineation, addition of cycle lanes, and improved amenity for pedestrians. Speed data collected 3 months after implementation showed a significant reduction in vehicle speeds on local roads and increased homogeneity of speeds on both local and collector roads. The objective speed data, combined with residents' speed choice ratings, indicated that the project was successful in creating two discriminably different road categories.

Indicators of maximal hiking performance in Laser sailors.

Laser class sailors have to hike out, i.e. hook their feet under the toe straps near the centreline of the boat and hold their upper bodies over the edge of the boat, to counteract the heeling forces generated by the sails. To identify the parameters that are associated with maximal hiking performance, this cross-sectional observational study measures various knee extensor and hip flexor muscle performance characteristics in 55 Laser sailors and correlates each with the area-under-the-curve hiking moment over 3 min of hiking on a hiking dynamometer (HM180). Our results showed that higher body mass and HM180 were significantly associated with better race scores (Spearman's rho = - 0.69 and - 0.62, respectively, both P < 0.01) in male sailors who participated in the National Inter-School Laser competition. Body mass (Pearson's correlation coefficient, r > or = 0.95, P < 0.01 in both males and females), maximum voluntary isometric strength of the quadriceps (r > or = 0.80, P < 0.01 in both males and females), and 3-RM knee extension strength (r > or = 0.80, P < 0.01 in both males and females) were associated with a higher HM180. The correlations between height, abdominal muscle endurance (crunches), explosive lower body strength (vertical jumps), cycling time-to-exhaustion, quadriceps strength endurance, or isometric quadriceps endurance with incremental loads (bucket test), and HM180 were weaker (r < 0.60). HM180 may be a useful performance indicator for Laser racing. Since strength measures correlated well with HM180, greater emphasis should be placed on developing maximum strength in the quadriceps to improve maximal hiking performance.

The effect of simulated school load carriage configurations on shoulder strap tension forces and shoulder interface pressure.

Recently, several studies have addressed the physical demands of school student's load carriage, in particular the load weight carried, using physical demands indicators such as oxygen consumption, gait, and posture. The objective of this study was to determine the effects of different load carriage configurations on shoulder strap tension forces and shoulder interface pressure during simulated school student's load carriage. A load carriage simulator was used to compare shoulder strap forces and shoulder pressure for 32 combinations of gait speed, backpack weight, load distribution, shoulder strap length and use of a hip-belt. The results showed that the manipulation of backpack weight, hip-belt use and shoulder strap length had a strong effect on shoulder strap tension and shoulder pressure. Backpack weight had the greatest influence on shoulder strap tension and shoulder pressure, whereas hip-belt use and then shoulder strap adjustment had the next greatest effects, respectively. While it is clear that researchers and practitioners are justified in focusing on load magnitude in backpack studies as it has the greatest effect on shoulder forces, hip-belt use and shoulder strap adjustment should also be examined further as they too may have significant effects on the demands placed on backpack users. Based on the present findings, school students should wear their backpacks with the least weight possible, use the hip-belt if present, allow a reasonable amount of looseness in the shoulder straps and should position the heaviest items closest to their back. However, more detailed work using human participants needs to be undertaken before these recommendations can be confirmed.

Development of activity monitoring for determining load carriage patterns in school students.

The loads that school students are carrying to, around and from school is an issue of increasing concern particularly as the long term effects of excessive load carriage on school students' musculoskeletal health is unknown. A greater understanding of the temporal patterns of students' load carriage, which usually involves backpacking, would assist in determining the magnitude of the problem that is faced by school students. The aim of this study was to determine the duration of school students' walking, running and stair climbing while backpacking and identify when students take off and put on their backpacks using activity monitoring and video, and therefore validate activity monitoring as a tool for measuring the temporal patterns of backpacking in school students. An activity monitor was secured in the backpacks of six school students while they completed a predefined physical activity course. Participants firstly completed the course following a set time pattern ('set course') and then repeated the course while performing activities as they pleased ('free course'). Video footage and activity monitor data were captured simultaneously. The activity monitor provided consistent visual differentiation between walking, running and taking off and putting on a backpack. The greatest variation between measures was for walking during the 'free course' (mean 8, SD 7 seconds), while the least variation between measures was for stair climbing during the 'set course' (mean 3, SD 2 seconds). There were no statistical differences between the activity monitor and video camera determined durations for any of the activities. These preliminary results suggest that activity monitoring may enable valid analysis of the temporal patterns of backpacking with little disruption to the user, although more work is required to verify this.