Background: We sought to investigate the effect of wearing shoes on joint range of motion, ground reaction force (GRF), and muscle activity (electromyography) in children with flat and normal feet during walking.
Methods: Nine children with flat feet and 12 children with normal feet aged 5 to 11 years were recruited. Each child was instructed to walk on a walkway in the barefoot and shod conditions. Joint range of motion, GRF, and electromyographic data within one gait cycle were collected simultaneously. Two-way analysis of variance was performed to evaluate the effects of foot type and shoe condition on the response measures.
Results: Children with flat feet had greater joint motion and higher muscle activities in the lower extremity, as well as lower vertical GRF and longer duration of the first peak forces in vertical and mediolateral GRFs than children with normal feet while walking. Compared with the barefoot condition, shoe wearing in both groups of children showed an increase in ankle dorsiflexion at heel strike, a decrease in anteroposterior GRF and its duration, and an increase in leg muscle electromyographic activities. Pelvic tilt range of motion was affected by the interaction of foot type and shoe condition.
Conclusions: Gait performance in pelvic tilt, hip flexion, and ankle dorsiflexion were different between the two groups of children. Wearing shoes increased the muscle activities of the shin. This finding can provide important information for clinical assessment of and shoe design for children with flat feet.