Abstracts of the 2017 International Workshop on Musculoskeletal and Neuronal Interactions

摘要

The Canadian 24-Hour Movement Guidelines for Children and Youth recommend at least 60 min/day of moderate to vigorous physical activity (MVPA), as well as vigorous activity (VPA) and muscle and bone strengthening activities at least 3 times/week. However, the type, intensity and duration of activities that strengthen bone remain unclear. Our objective was to assess if minutes of MVPA, VPA and estimated bone impacts would independently predict variance in radius and tibia bone strength in children. We recorded 7-day physical activity of 49 children, mean age=11 (SD 1.7y), using accelerometers and estimated bone strength at the radius and tibia using peripheral quantitative computed tomography. We assessed if daily average MVPA, VPA, and peak acceleration impact counts (≥3.9 g resultant magnitude) would predict variance in bone strength after adjusting for sex, body mass and site-specific muscle area. We report significant (P<0.05) standardized β-coefficients and R2 of the adjusted linear regression models. MVPA mean 50.2 (SD 22.6) min/day, VPA 18.6 (10.6) min/day, and impacts 70.9 (59.4) counts/day did not predict variance in bone strength at the radius. VPA (β=0.24, R2=0.55) predicted variance in distal tibia strength. MVPA (β=0.20, R2=0.71), VPA (β=0.24, R2=0.72), and impacts (β=0.21, R2=0.71) predicted variance in tibia shaft strength. Based on our models, a 10-minute increase in MVPA or VPA could increase tibia bone strength by 3-7%. An increase of 63 impact counts/day could similarly increase tibia bone strength by 7%. Our predictions and objectively quantified activities associated with forearm strength need to be assessed in future intervention studies.