Coping with asymmetry: How infants and adults walk with one elongated leg

The stability of a system affects how it will handle a perturbation: The system may compensate for the perturbation or not. This study examined how 14-month-old infants—notoriously unstable walkers—and adults cope with a perturbation to walking. We attached a platform to one of participants’ shoes, forcing them to walk with one elongated leg. At first, the platform shoe caused both age groups to slow down and limp, and caused infants to misstep and fall. But after a few trials, infants altered their gait to compensate for the platform shoe whereas adults did not; infants recovered symmetrical gait whereas adults continued to limp. Apparently, adult walking was stable enough to cope with the perturbation, but infants risked falling if they did not compensate. Compensation depends on the interplay of multiple factors: The availability of a compensatory response, the cost of compensation, and the stability of the system being perturbed.     

Quality of Life Assessment for Physical Activity and Health Promotion

Despite the clear relationship of physical activity and quality of life (QoL), QoL measures are seldom targeted for physical activity and health promotion. The current research attempted to address that gap by developing a QoL measure based on a conceptual model that reflects positive health and is relevant for physical activity and health promotion programs. In the project, which extended over three phases, an initial 70-item QoL survey was administered to university students and community program participants (total n = 512) along with measures of satisfaction with life and physical activity. Exploratory and confirmatory factor analyses revealed clear social, emotional, cognitive, physical, spiritual and functional (ADL) QoL factors as well as integrated QoL. The resulting 32-item QoL Survey fits the conceptual model, demonstrates logical relationships with physical activity and has sufficient psychometric properties for use in related research and health promotion programs.     

Perceived physical competence and body image as predictors of perceived peer acceptance in adolescents

The purpose of this study was to investigate the relationships among perceived physical competence, body image, and peer acceptance. Body image was considered as a possible mediator of the relationships between perceived physical competence and peer acceptance. Adolescents (N = 838) completed questionnaires. Direct and indirect effects of perceived physical competence and body image on perceived peer acceptance were explored using structural equation modelling. Gender differences were found and the structural mediation model was a reasonable fit to the data; the pattern of relationships in the model was different for adolescent males and females.