A new protocol for 3D assessment of foot during gait: application on patients with equinovarus foot.

BACKGROUND: The aim of this study is to assess the clinical value of a recently introduced original protocol for full three dimensional analysis of ankle rotations in patients with equinovarus foot. METHODS: A preliminary study merging the Total3Dgait protocol and the conventional Vicon® Plug-in-Gait marker-sets on five patients with foot deformity was performed to compare the output exactly over the same gait cycles. In the second study, 15 patients with equinus varus foot were assessed retrospectively by means of the Total3Dgait protocol before and after surgery. Data on ankle kinematics were compared to those of a control group. The Functional Ambulation Categories scale and other goals such as orthosis/aids removal, decrease in foot pain, healing of calluses and sores were considered as measures of clinical outcome. FINDINGS: The Total3Dgait protocol provides additional joint motion, in the coronal and transverse planes. Kinematics in the three anatomical planes improved significantly although no changes in time-distance parameters were evident. Improvement in clinical outcome measures was also achieved. INTERPRETATION: The new protocol provides valuable additional data in measuring full three dimensional kinematics of the foot during gait. Whereas the speed of walking was unchanged after surgery for most of patients, the kinematic changes in the three anatomical planes, as measured by the new protocol, were the only measures able to demonstrate motion changes induced by surgery at the foot and to explain subject-specific gains as improvement in stability during walking, relief of pain, calluses and sores, and removal or modification of foot orthosis and aids