Acute Changes in Fascicle Behavior and Electromyographic Activity of the Medial Gastrocnemius during Walking in High Heeled Shoes

Abstract

Objective: The purpose of this study was to investigate the acute effect of walking on high heels on the behavior of fascicle length and activation of the lower limb muscles. Methods: Twelve healthy inexperienced high heel wearers (age: 23.1 ± 2.0 yr, height: 162.4 ± 4.9 cm, weight: 54.4 ± 8.5 kg) participated in this study. They walked in high heels (7 cm) and barefoot on a treadmill at their preferred speed. During the gait analysis, the lower limb joint kinematics were obtained using a motion analysis system. In addition, the changes in fascicle length and the level of activation of the medial gastrocnemius (MG) were simultaneously monitored using a real-time ultrasound imaging technique and surface electromyography, respectively. Results: The results of this study show that the MG fascicle operates at a significantly shorter length in high heel walking (37.64 ± 8.59 mm to 43.99 ± 8.66 mm) in comparison with barefoot walking (48.26 ± 9.02 mm to 53.99 ± 8.54 mm) (p < .05). In addition, the MG fascicle underwent lengthening during high heel walking with relatively low muscle activation while it remained isometric during barefoot walking with relatively high muscle activation. Conclusion: Wearing high heels alters the operating range of the MG fascicle length and the pattern of muscle activation, suggesting that prolonged wearing of high heels might induce structural alterations of the MG that, in turn, hinder normal functioning of the MG muscle during walking.