Journal of

Introduction: Lateral Patellar Compression Syndrome (LPCS), one of the most common patellofemoral disorders among athletes, is associated with both proximal biomechanical impairments (e.g., hip muscle weakness) and local dysfunctions (e.g., imbalance between vastus medialis and vastus lateralis activity). Despite conflicting evidence about the effectiveness of isolated exercise protocols, this study aimed to compare the effects of targeted hip, knee, and combined exercise protocols on key muscle activation patterns in LPCS.
Methods: In a quasi-experimental pretest-posttest study with a control group, 57 athletes with LPCS were assigned to three intervention groups (Hip: n = 13; Knee: n = 15; Combined: n = 14) and a healthy control group (n = 15). Electromyographic activity of the vastus medialis obliquus (VMO), vastus lateralis (VL), and gluteus medius (GM) was recorded during a single-leg stance task using surface EMG, following SENIAM guidelines. Intervention groups completed their respective 8-week training protocols (3 sessions/week). Root mean square values were analyzed using paired t-tests, repeated-measures ANOVA, and one-way ANOVA in IBM SPSS Statistics software (Version 26).
Results: Compared to controls, LPCS participants exhibited significantly lower activation of  VMO and GM, and higher activation of VL (all P < 0.01). The combined protocol resulted in the most remarkable simultaneous improvements in VMO and GM (P < 0.01), while isolated knee and hip protocols specifically enhanced VMO and GM, respectively (P < 0.01). VL activity remained unchanged (P > 0.01).
Conclusions: The combined exercise protocol, due to its synergistic effect on the simultaneous activation of the VMO and GM, seems to be the most effective approach for neuromuscular rehabilitation in athletes with LPCS. These findings highlight the importance of incorporating both hip- and knee-focused exercises into rehabilitation programs.