Effect of Adding Single-Leg Balance Training With a Hip Muscle Activation Program on Frontal Plane Movement Quality: A Randomized Controlled Trial in Adult Females

Dynamic knee valgus is a leading contributor to knee joint injuries, especially in female athletes. Poor proprioception and single-leg stability can contribute to this movement pattern. Improving proximal muscle strength and muscle activation has been shown to improve dynamic knee valgus, but little is known about the combination of single-leg balance training plus gluteal muscle activation training. The purpose of this study was to investigate if an 8-week home exercise program of hip muscle activation plus balance training improved frontal plane movement quality more than muscle activation training alone. Thirty-four female participants were tested on the forward-step-down test (measure of frontal plane movement quality) and unipedal stance test (measure of single-leg balance) at baseline, then randomized into a control (hip only) or experimental (hip and balance) group. Measures were repeated after the home exercise program was completed. Both groups statistically improved forward-step-down test scores at posttesting but did not have significant changes in single-leg balance or gluteal muscle activation. Forward-step-down test scores did not differ between groups, and the posttest improvement did not meet clinical significance. While the hip muscle activation program improves frontal plane movement quality, single-leg balance training does not add value to the program. Future studies could focus on nonhealthy participants or utilize a combination of muscle activation and neuromuscular re-education to further improve movement patterns.