Functional Performance Of Older Persons With Normal, Pronated And Supinated Foot

Aging process is accompanied with muscle degeneration that may affect functional performance, especially those with foot deformities. This study aimed to investigate the muscle strength [lower extremity (LES), ankle plantarflexors (APS)] and balance performance, and determine the relationship of muscle strength with balance performance in older persons with different types of foot posture. A cross-sectional study was conducted among 90 community-dwellers, age >= 60-year-old. Types of foot (normal, pronated, supinated) were identified using the Foot Posture Index (FPI) (each group, n= 30). The LES and APS were measured using the 30-sec chair-rise and heel-rise tests, respectively. Balance performance was measured using the four square step test (FSST). Analysis showed significant differences in APS (p= 0.012) and balance performance (p= 0.049) among different types of foot posture. Participants with supinated (13.81 +/- 4.32 rep) foot, had the lowest APS followed by normal (14.53 +/- 4.62 rep) and pronated (16.60 +/- 4.27 rep) foot. The pronated foot (15.26 +/- 5.62 s) had a longer duration to complete the FSST, followed by the supinated (13.22 +/- 2.99 s) and normal (12.77 +/- 2.82 s) foot. No significant difference was found in LES (p> 0.05) among types of foot. It was found that balance performance was significantly correlated with LES in the normal (r=-0.655, p= 0.00) foot, as well as with APS in the pronated foot (r= 0.464, p= 0.010). This study revealed that older persons with pronated foot are more vulnerable to functional performance decline. Hence, they may be at risk of falls and mobility impairment. Intervention targeted for the ankle and foot may differ depending on the types of foot.