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

Objective : The purpose of this study was to investigate the acute effect of high heel walking 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 yrs, height: 162.4±4.9 cm, weight: 54.4±8.5 kg) participated in this study and performed walking in high heels(7 cm) and barefoot on treadmill with preferred speed. During the gait, 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 showed that the MG fascicle operated in significantly shorter length in high-heel walking(min 37.64±8.59 mm to max 43.99±8.66 mm) in comparison with barefoot walking(min 48.26±9.02 mm to max 53.99±8.54 mm)(p<.05). Also, the MG fascicle underwent lengthening during high-heel walking with relatively low muscle activation while it remained isometrically during barefoot walking with relatively high muscle activation. Conclusion : Thus, it has been verified that wearing of high heels altered 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 and, in turn, hinder normal functions of the MG muscle during walking.