Female Soccer Players at High Risk of Injury Maintain Improved Knee Abduction Load Six Months After Neuromuscular Training Program

OBJECTIVE: To estimate immediate and long-term (retention) improvements in knee abduction moment (KAM) following a neuromuscular training (NMT) program with augmented biofeedback in individuals at high and low risk for injury. DESIGN: Secondary analysis of a randomized controlled trial. METHODS: One hundred fifty adolescent female soccer players were enrolled in a 6-week NMT program and randomized to biofeedback training groups: NMT+Hip-focus, NMT+Knee-focus, or NMT with a sham biofeedback. NMT was completed 3 times each week with augmented biofeedback delivered once per week. Standard 3D motion analysis of a drop vertical jump over artificial turf with embedded force platforms was performed at baseline (PRE), immediately following training (POST), and 6-months post-training (RET). Baseline measures of KAM were used to stratify participants into low- (n = 87, 12.7±2.2yrs, 153.0±11.4cm, 47.2±11.8kg) and high-risk (n = 44, 14.0±1.8yrs, 161.6±5.8cm, 53.5±9.2kg) groups, based on a previously determined cut point. A mixed-design ANOVA with between group factors of risk (High, Low) and training group (NMT+H, NMT+K, NMT), and a repeated within group factor of session (PRE, POST, RET) were used for the analysis. RESULTS: A significant interaction was identified between risk and session (p<0.001). Within training groups, the high-risk group had a significant reduction in KAM from baseline to post-test, and from baseline to 6-months (PRE: −37.5±9.0Nm, POST: −25.2±11.4Nm, RET: −29.4±14.5Nm). There were no changes in the low-risk group (PRE: −12.2±6.2Nm, POST: −12.2±7.6Nm, RET: −12.9±8.7Nm). CONCLUSION: Female soccer (football) players with knee biomechanics that put them at high risk for ACL injury had improved KAM following a NMT program. The changes in KAM remained at six months after training.