Influence of carrying book bags on gait cycle and posture of youths

The purpose of this investigation was to determine the impact of different methods of carrying book bags on static posture and gait kinematics of youths aged 11–13 years. Surveys identified group descriptive characteristics of subjects and book bags. Ten subjects representing the best composite of the mean characteristics of this population were filmed for both static posture and dynamic conditions of one stride length. Subjects participated in four conditions: without bag (WO), one-strap backpack (1BP), two-strap backpack (2BP), and one-strap athletic bag (ATH). Lateral spinal deviation was not significantly different between 2BP and WO. However, differences (±SE) were observed between 1BP (8.5±0·7°) and ATH (8·3±2·4°) as compared with WO (1·9±0·5°). Shoulder elevation from a horizontal position showed no difference between WO and 2BP. Without bag (2·0±0·9°) was different from 1BP 17·6±1·8°) and ATH (15·6±2·1°). 1BP was also different from 2BP (3·4 ±1·1°). Bag carrying significantly decreased stride leng...