Age Is More Predictive of Safe Movement Patterns Than Are Physical Activity or Sports Specialization: A Prospective Motion Analysis Study of Young Athletes

Abstract

Background: Movement quality and neuromuscular balance are noted predictors of acute injury. Early sports specialization and extremely high activity levels have been linked to elevated risk of injury. Purpose: To investigate for any relationships among quality of physical movement, quantity of physical activity, and degree of sports specialization in a healthy cohort of active children and adolescents. Study Design: Cross-sectional study with prospectively collected data. Methods: Healthy children between the ages of 10 and 18 years were recruited and completed the Hospital for Special Surgery Pediatric Functional Activity Brief Scale to assess quantity of physical activity and the Jayanthi scale to assess degree of sports specialization (high, score of 2 or 3; low, score of 0 or 1). Movement quality was assessed using motion analysis sensors during 5 repetitions of 4 different jumping and squatting motions, with a maximum score of 100 per participant. Independent-samples t tests were used to compare participants with high versus low specialization on physical activity and movement quality. A Spearman correlation was used to determine the relationship between quantity of physical activity and movement quality, and linear regression was used to assess for the effect of participant age on relevant covariables. Results: Final analyses included 147 participants (72% male) with a mean ± SD age of 13.4 ± 2.2 years. Participants who were highly specialized displayed better movement quality than did participants with low sports specialization (27.6 ± 14.0 vs 19.8 ± 10.1; P < .01). Participants who were highly specialized had significantly higher activity levels (24.6 ± 5.9 vs 18.1 ± 6.9; P < .001). Movement quality was moderately correlated with physical activity level (r = 0.335; P < .001). Physical activity; hours of organized sports activity; hours of free, unorganized physical activity; and specialization level were not significant predictors of movement quality when controlling for age. Age alone predicted 24.2% of the variance in the overall movement quality score (R2 = 0.242; B = 3.0; P < .001). Conclusion: This study found that sports specialization and physical activity levels were not associated with movement quality when controlling for age, which was the most important variable predicting athletic movement quality. Although all participants displayed movement patterns that were associated with high risk for injury, overall movement quality improved with advancing chronological age. Clinical Relevance: All young athletes should ensure that neuromuscular training accompanies sport-specific training to reduce risk of injury.