Prediction of Dynamic Postural Stability During Single-Leg Jump Landings by Ankle and Knee Flexibility and Strength

摘要

Context: Dynamic postural stability is important for injury prevention, but little is known about how lower-extremity musculoskeletal characteristics (range of motion [ROM] and strength) contribute to dynamic postural stability. Knowing which modifiable physical characteristics predict dynamic postural stability can help direct rehabilitation and injury-prevention programs. Objective: To determine if trunk, hip, knee, and ankle flexibility and strength variables are significant predictors of dynamic postural stability during single-leg jump landings. Design: Cross-sectional study. Setting: Laboratory. Participants: 94 male soldiers (age 28.2 +/- 6.2 y, height 176.5 +/- 2.6 cm, weight 83.7 +/- 26.0 kg). Intervention: None. Main Outcome Measures: Ankle-dorsiflexion and plantar-flexion ROM were assessed with a goniometer. Trunk, hip, knee, and ankle strength were assessed with an isokinetic dynamometer or handheld dynamometer. The Dynamic Postural Stability Index (DPSI) was used to quantify postural stability. Simple linear and backward stepwise-regression analyses were used to identify which physical characteristic variables were significant predictors of DPSI. Results: Simple linear-regression analysis revealed that individually, no variables were significant predictors of the DPSI. Stepwise backward-regression analysis revealed that anlde-dorsiflexion flexibility, ankle-inversion and-eversion strength, and knee-flexion and-extension strength were significant predictors of the DPSI (R-2 = .19, P = .0016, adjusted R-2 = .15). Conclusion: Ankle-dorsiflexion ROM, ankle-inversion and-eversion strength, and knee-flexion and-extension strength were identified as significant predictors of dynamic postural stability, explaining a small amount of the variance in the DPSI.