Objective: This study investigated the effect of different heel heights on the electromyographic (EMG) activity of the vastus medialis oblique (VMO) and vastus lateralis (VL) during treadmill walking.
Methods: 17 young healthy women (age 22.06 +/- 1.2 years) were recruited. With and without a slope, the participants walked on a treadmill at a speed of 2 km/h for 90 seconds under three conditions: barefoot, 3-cm heels, and 7-cm heels. Data for surface EMG was collected from the standard sites of the VMO and VL during treadmill walking.
Results: Significant differences were observed in the VL EMG activity on the non-dominant side between barefoot and 7-cm heels while walking with and without a slope (p< 0.05). VMO:VL EMG ratios significantly decreased for the non-dominant side while walking with and without a slope (p < 0.05). The post hoc pair-wise comparisons revealed significant differences in barefoot vs. 7-cm heel and 3-cm vs. 7-cm heels.
Conclusion: The findings suggest that high-heeled shoes may contribute to a potential change of the knee joint muscles while walking, especially on the non-dominant side. This study provides information that will notify future research on how high-heeled shoe affects muscle activity around the knee joint.