Abstract: Structure and function of foot musculoskeletal system could be affected by wearing high-heeled shoes for daily activities. This work explored the effects of long-term wearing high-heeled shoes on the plantar soft tissues architecture and stiffness, plantar pressure, and foot morphology in walking or standing. Nineteen women with more than 10-year experience in wearing high-heeled shoes were selected as the experimental group, while twenty women without high heel wearing experience were chosen as the control group. The ultrasonic diagnostic system was used to test their plantar soft tissues' thickness, cross-sectional area, and shear wave velocity; the SENSOR MEDICA pressure test system was applied to record their plantar pressure; the footprint method was adopted to collect their footprint data. The differences between groups were analyzed by using the independent sample t test. It was found that the thickness, shear wave velocity and cross-sectional area of abductor hallucis and flexor hallucis brevis in the experimental group were significantly smaller than those in the control group. Compared to the control group, the experimental group possessed the higher thickness and cross-sectional area of flexor digitorum brevis, fore/medial and rear foot pressure, contact area of first metatarsal bone, hallux valgus angle and heel angle. The long-term standing and walking with high-heeled shoes could weaken the abduction and metatarsal flexion of hallux, aggravate forefoot pronation, increase the pressure of the medial longitudinal arch, result in the muscle fiber of flexor digitorum brevis hypertrophy, and increase the plantar pressure in rearfoot. It is suggested that the wearers of high-heeled shoes should focus on training hallux abduction and plantar flexion, as well as strengthening the exercises of centripetal contraction of the flexor toe muscles and foot supination.

Key words: high-heeled shoes, plantar architecture, stiffness, plantar pressure