Multi-segment coordination within the foot in children with and without clubfoot during walking, toe raises and single limp hopping
Children born with congenital idiopathic clubfoot have significant foot deformity that requires treatment at birth. Long term outcomes in patients who were treated for congenital clubfoot have reported gastrocnemius weakness, limited ankle motion and reduced ankle power during gait. There have been few studies, however, that have directly assessed how these changes in foot mechanics affect the ability to perform more challenging tasks. The purpose of this study was to assess kinematics, kinetics and joint coupling within the foot in children previously treated for clubfoot. Sixteen children with 23 affected clubfeet and 16 children without history of clubfoot underwent three-dimensional motion analysis using a multi-segment foot model, during three activities: walking, toe-raises and hopping. Children with clubfoot demonstrated a reduction of sagittal plane hindfoot range of motion during walking, with limited forefoot range of motion during toe raises and hopping. Decreased ankle power generation was seen during all three activities in children with clubfoot when compared to children without clubfoot. The addition of joint coordination assessment identified reductions in in-phase coupling during hopping and toe raise activities, which were not detected with kinematic evaluation alone. Overall children with clubfoot had reduced center of mass excursion during hopping and reduced heel height during toe raises. Although outcomes in clubfoot can vary greatly, the combination of multi-segment foot kinematics, inter-joint and intra-segment foot coupling, and age-appropriate, challenging protocols which include tasks other than overground walking, can provide a means to define foot function and mobility in both children and adults. Understanding the biomechanics within the foot may help physicians with treatment-decision making, and lead to improved functional outcomes in patients with clubfoot and/or other foot pathologies.