Background and Objective: Pronated foot is one of the lower extremity deformities, and obesity is considered a major dilemma in modern society. The present study aimed to determine the interactive effect of overweight and pronated foot on the frequency spectrum of lower extremity muscle activity in men during running.
Methods: This quasi-experimental study was conducted on 40 male students aged 21–35 years, who were assigned non-randomly into four groups of 10: Normal weight with normal foot, obese with pronated foot, obese with normal foot, and normal weight with pronated foot. The activity of selected muscles, including the tibialis anterior, medial gastrocnemius, vastus lateralis, vastus medialis, rectus femoris, biceps femoris, semitendinosus, and gluteus medius, was recorded during running using electromyography (EMG).
Results: The frequency spectrum of the electrical activity of the biceps femoris muscle was significantly lower in the “obese with normal foot” group compared to the “normal weight with pronated foot” group (P<0.05). The interactive effect of fatigue and group was not statistically significant.
Conclusion: In the “obese with pronated foot” group, the observed increase in muscle activity may reflect the neuromuscular system's attempt to manage biomechanical loads. Furthermore, individual differences in movement patterns, fitness levels, and compensatory strategies may contribute significantly to variations in muscle activity.