Valgus Control Feedback and Taping Improves the Effects of Plyometric Exercises in Women With Dynamic Knee Valgus.

BACKGROUND: Female athletes are more predisposed to anterior cruciate ligament (ACL) injuries in comparison with their male counterparts. Research on ACL injury prevention strategies has demonstrated beneficial effects of plyometric exercises and feedback (FB) during the exercises. FB has resulted in reductions in vertical ground-reaction force and kinematic risk factors associated with ACL injury. Furthermore, taping (TP) may draw attention to the restriction created by the tape and serve as real-time biofeedback. The additional influence of FB and TP on plyometric exercises has not been determined.

HYPOTHESIS: FB and TP interventions delivered during plyometric exercises would result in positive changes in biomechanics and muscle onset in female athletes displaying dynamic knee valgus.

DESIGN: Controlled trial.

SETTING: University research laboratory.

LEVEL OF EVIDENCE: Level 2.

METHODS: Forty-eight active female athletes were divided into 3 groups: control (n = 16), plyometric training with FB (n = 16), and plyometric training with TP (n = 16). The 2 experimental groups performed a 6-week exercise program with either FB or TP. The control group continued its regular team schedule. Knee joint position sense, landing error scoring system (LESS), and the onset of muscle activation (the point at which muscle activation exceeds 3 standard deviations over baseline and continued above this threshold for at least 25 ms) before landing for the rectus femoris, vastus medialis, vastus lateralis, gluteus medius, semitendinosus, and biceps femoris during pre- and posttests were measured.

RESULTS: The vastus lateralis onset later in the TP group compared with the FB group ( d [95% CI] = 0.64 [0.35-0.82], P = 0.01). Joint position sense accuracy improved only in the TP group ( d = -0.63, P = 0.001). Both the FB ( d = -0.85, P = 0.001), and TP ( d = -0.82, P = 0.001) groups improved in LESS scores.

CONCLUSION: The results of the present study showed that plyometric exercises with FB or TP affect LESS and the onset of the vastus lateralis in active uninjured women with dynamic knee valgus, while TP improves joint position sense. Therefore, when more accurate joint position sense is desired, practitioners may use plyometric with TP. If an improved LESS score is desired, plyometrics with either TP or FB are acceptable.

CLINICAL RELEVANCE: Our findings indicate that female athletes may benefit more when completing a plyometric training program with a TP versus an FB. Trainers, coaches, and clinicians should consider utilizing instructions that promote an external focus when implementing plyometric training programs with male athletes.