The Effects of Shoe Type on Muscle Activity During Step Up and Step Down Motions

Abstract

Hiking is a popular activity with many health benefits. Evidence suggests that 75% of hiking related injuries are of the lower extremities and that footwear choice may play a role in these injuries. PURPOSE: To evaluate the connection between footwear choice and lower extremity muscle activity during step-up and step-down movements, specifically the vastus medialis (VM), tibialis anterior (TA), biceps femoris (BF), and gastrocnemius (G). METHODS: Eleven male and female hikers (26 ±5 years, 80.3±12.6 kg, 1.8±0.08 m) performed three step-up and step-down trials on three AMTI force platforms in both hiking boots and hiking shoes. Footwear weights were standardized. Surface electrodes recorded EMG data of the four muscles of interest on the dominant leg during each trial. Maximal voluntary isometric contractions (MVIC) were conducted for each muscle and used to normalize EMG. Paired t-tests were used to compare differences in muscle activity between footwear. RESULTS: Mean EMG amplitude (% MVIC) of BF were 11.37±5.65% in boots and 11.61±5.93% in shoes. Mean EMG of G in boots were 27.08±25.61% and 43.28±44.30% in shoes. Mean EMG of VM in boots were 41.26±18.53% and 41.34±18.55% in shoes. Mean EMG of TA in boots were 16.83±6.46% and 15.71±5.59% in shoes. No significant differences were found in muscle activity between footwear. CONCLUSION: Muscle activation is not affected by footwear, therefore the user can choose either hiking boots or hiking shoes in a stepping task and not overwork any specific musculature. These results may be valuable for hikers, military personnel, or firefighters when choosing footwear.