Relationship between the mobility of medial longitudinal arch and postural control.

Objective: The aim of this study was to analyze the relationship between the medial longitudinal arch mobility and static and dynamic balance.

Methods: A total of 50 subjects (25 female, and 25 male; Mean age: 22.2 ± 1.3 years; BMI: 22.8 ± 3.8 kg/m) were included in this study. The relative arch deformity (RAD) was calculated with both 10% and 90% weight bearing (WB). Static balance was evaluated with Single Leg Stance Test and dynamic balance with TechnoBody PK 200WL computerized balance device. Subjects were evaluated for goniometric measurements of lower extremity joints, leg dominance and leg-length discrepancy.

Results: Bipedal dynamic balance was correlated with both feet length at 10% WB and 90% WB. There was a correlation between the dynamic balance on dominant foot and RAD value on the aspect of Medium Speed (r = -0.32, p = 0.02), Perimeter Length (r = -0.32, p = 0.02) and Anterior-Posterior Sway (r = 0.36, p = 0.01). Static balance was unaffected by RAD value when the visual system was eliminated.

Conclusion: Our results suggest that decrease of arch mobility on the dominant foot is associated with posterior sway by causing knee or hip strategy and preventing ankle strategy even in small perturbations. The rate of deviation from the equilibrium point and the degree of total swaying increase when arch mobility decreases.