Force, Power, and Morphology Asymmetries as Injury Risk Factors in Physically Active Men and Women

This study aimed to investigate whether asymmetry of force, power, and tissue morphology are lower limbs (LL) injury risk factors in physically active adults. Fifty-eight men aged 23.8 +/- 1.2 years and forty-seven women aged 23.3 +/- 1.0 years were examined. Physical activity level was measured by the International Physical Activity Questionnaire, and injury data were collected with the Injury History Questionnaire. The countermovement jump was performed to evaluate force and power. LL tissue composition was evaluated by a bioimpedance analyzer. The symmetry indices were calculated. A comparison between injured and non-injured subjects in both sexes was conducted to determine indices associated with injuries. The symmetry indices cut-off points were calculated to establish values indicating a significant injury risk increase, and logistic regression was performed. The relative peak force asymmetry above 4.049% was associated with increased injury risk in men. The LL skeletal muscle mass asymmetry above 3.584% was associated with a higher injury risk in women. Increased asymmetry in indicated indices by 1% was associated with 19.8% higher injury risk in men and 82.6% in women. Asymmetry proved to be an injury risk factor. However, a more suitable index for men is relative peak force asymmetry, whereas LL skeletal muscle mass asymmetry is more suitable for women.