Changes of gait pattern, muscle activity, and perceived comfort in response to variations of height-elevating insoles in young adults.

The purpose of this study was to investigate changes of gait pattern, muscle activity, and perceived comfort in response to variations of height-elevating insoles (HEIs) in young adults. The subjects of this study were 30 young adults who voluntarily consented to participate in this experiment after listening to its purpose and method. They were divided into 3 groups who wore HEIs height (0, 3, and 7 cm). Each group consisted of 10 young adults and wore the HEIs for 4 hr a day. Electromyographic signals were collected from the tibialis anterior, the gastrocnemius, the hamstring, and the right and the left erector spinae (ES) before and after walking with the HEI. Gait pattern was measured before and after walking with the HEI. Perceived comfort was measured after a subject wore the insoles for 4 hr. The activities of ES showed significant differences among the three groups. The activity of the left ES was significantly different between groups 1 (0 cm) and 2 (3 cm) and groups 1 and 3 (7 cm). The activity of the right ES was significantly different between groups 1 and 3. The left stride length and the left step length showed significant differences between groups 1 and 3. Perceived comfort was significantly different among the three groups. As the HEIs increased, the activities of ES were gradually increased and the left step length and stride were decreased. Using of higher HEIs over 4 hr may be occurred excessive activities of the ES, abnormal gait patterns, and perceived discomfort.