The Effects of Changes of Ankle Strength and Range of Motion According to Aging on Balance

OBJECTIVE To investigate the changes of ankle strength and range of motion with aging and which of the ankle strength and range of motion are contributed to balance. METHODS Sixty healthy people (24 men and 36 women) have undergone tests for ankle strength and range of motion, using Biodex System 4 Pro; a one-leg balance, including postural sway and stability index using a Balance System; in which data were collected in a self-reported Desmond fall risk questionnaire. RESULTS Participants are classified into 3 groups by age (group 1, 20-40 years; group 2, 40-65 years; group 3, over 65 years). Stability index and postural sway is significantly increased with aging. Ankle plantarflexor strength and ankle eversion range of motion is significantly decreased with aging. Pearson's correlation revealed that ankle plantarflexor strength is significantly correlated with anterior/posterior sway, and ankle eversion range of motion is significantly correlated with medial/lateral sway in the aged group (over 65 years). CONCLUSION Stability, ankle plantarflexor strength, and eversion range of motion is declined with aging. In addition, strength of ankle plantarflexor and eversion range of motion is significantly correlated with balance stability. Further studies are needed for programs to improve the strength of plantarflexor, and range of motion of eversion of the ankle are beneficial in improving balance, stability, and prevention of falling in the elderly.