Lower Extremity Muscle Activations in Response to Different Medial Longitudinal Arch Height during the Dynamic Balance Test

Abstract

OBJECTIVES This study aimed to investigate whether muscle activation differs based on foot arch height and to examine the association between foot arch height and muscle activation during the dynamic balance test. METHODS Twenty-five healthy young males were classified into three arch groups (low, normal, and high arch groups) using the navicular drop test. Lower extremity muscle activation was assessed during the balance test. RESULTS The high-arch group showed higher muscle activation of the vastus lateralis than the low- and normalarch groups in the anterior direction and higher muscle activation in the posterolateral direction than the low-arch group. In addition, a higher medial longitudinal arch height was associated with increased muscle activation of the vastus lateralis in the anterior direction during the modified star excursion balance test. CONCLUSIONS Alteration in the foot arch height may influence the muscle activation pattern during the dynamic balance test. Increased vastus lateralis muscle activation in high-arch group and association higher medial longitudinal arch height and vastus lateralis activation may reflect compensatory strategies due to reduced plantar sensory input and greater loading on the lateral part of the foot. Our findings would provide a foundation for future research and contribute to understanding altered muscle activation patterns at different foot arch heights.