RESUMEN
BACKGROUND: Multi-segment foot models have been used to quantify foot kinematics during walking. However, walking kinematics is not sufficient to assess hindfoot flexibility (available range of hindfoot varus-valgus motion). The modified Shriners Hospitals for Children - Greenville (mSHCG) foot model has been used to quantify hindfoot flexibility with Coleman block test (peak hindfoot valgus) and Root test (peak hindfoot varus). Sensitivity of mSHCG foot model to detect clinically relevant difference in hindfoot flexibility measures for planovalgus (PV) and cavovarus (CV) feet has not been demonstrated. RESEARCH QUESTION: Can mSHCG foot model detect statistically significant difference in hindfoot flexibility measures between PV, CV and typically developing (TD) feet? METHODS: Hindfoot flexibility assessment was completed for 32 PV (37 feet), 27 CV (37 feet) and 20 TD (40 feet) individuals. Hindfoot position relative to tibia in coronal plane was measured in three postures: standing, heel raise and Coleman block test. Radiographic measures in standing position were also completed for PV and CV individuals and their correlation with hindfoot flexibility measures were evaluated. RESULTS: Statistically significant (p<0.001) differences were observed between three groups (TD, PV, CV) in all three hindfoot flexibility measures- (i) Hindfoot varus in standing position (ii) Peak hindfoot varus in heel raise and (iii) Peak hindfoot valgus in Coleman block test. There was relatively stronger correlation (R2=0.407-0.854) between three radiographic measures and hindfoot varus in standing position. Correlation between hindfoot range of motion towards valgus from standing to Coleman block test and the three radiographic measures was weaker (R2=0.2329-0.3042). SIGNIFICANCE: Hindfoot flexibility assessment can detect statistically significant difference between PV, CV and TD feet and provides additional information about available dynamic range of motion of hindfoot in the coronal plane that cannot be predicted from radiographic measures. Therefore, hindfoot flexibility assessment may assist in treatment planning of foot deformities.
RESUMEN
INTRODUCTION: Effective public health interventions targeting factors that influence physical activity are urgently needed to reduce the age-related decline in physical activity in youth. The purpose of this study was to identify associations between physical activity and a set of potential influences on physical activity in children as they transition from elementary to high school. METHODS: Participants were 951 children from South Carolina school districts who completed outcome and independent variable measures on at least two time points from the 5th to 11th grades in 2010-2017. The primary outcome variable was physical activity, measured by accelerometry. Independent variables included a comprehensive set of variables in the child, parent/home, school, and community domains. Children, parents and school administrators, and staff completed questionnaires to assess psychosocial and home, school, and neighborhood environmental influences. Growth curve analyses identified independent variables associated with physical activity over time, either as a main effect or as an interaction with age. RESULTS: As main effects, self-efficacy, self-schema, sport participation, weekday outdoor hours, importance of child participating in sports and physical activity, safe to play outside, and Physical Activity Resource Assessment weighted score were positively associated with physical activity. The associations between physical activity and enjoyment motivation, appearance motivation, weekend outdoor time, and home equipment exhibited significant interactions with age. Enjoyment motivation influenced physical activity during the earlier years, whereas the remaining three variables influenced physical activity in the later years. CONCLUSIONS: Interventions should target multiple domains of influences that may vary by age.