Invasive in vivo measurement of rear-, mid- and forefoot motion during walking

Abstract

The aim of this work was to use bone anchored external markers to describe the kinematics of the tibia, fibula, talus, calcaneus, navicular, cuboid, medial cuneiform, first and fifth metatarsals during gait. Data were collected from six subjects. There was motion at all the joints studied. Movement between the talus and the tibia showed the expected predominance of sagittal plane motion, but the talocalcaneal joint displayed greater variability than expected in its motion. Movement at the talonavicular joint was greater than at the talocalcaneal joint and motion between the medial cuneiform and navicular was far greater than expected. Motion between the first metatarsal and the medial cuneiform was less than motion between the fifth metatarsal and cuboid. Overall the data demonstrated the complexity of the foot and the importance of the joints distal to the rearfoot in its overall dynamic function.

Introduction

The kinematics of the foot and ankle during walking are a topic of great interest both from the biomechanical and clinical aspect. Previous clinical experimental research has provided descriptions of calcaneal motion relative to the leg, tibial rotation relative to the foot, and the motion of various definitions of ‘forefoot’ or ‘midfoot’ segments relative to the heel [1], [2], [3], [4]. These studies have utilised skin-mounted markers to derive information on the motion of bones or assumed rigid segments during walking. There are several difficulties with describing the foot and ankle in this way. Firstly, there is good evidence that skin movement artefacts are likely to reduce the validity of the kinematic data [5], [6], [7], although it is not clear how they affect different parts of the foot. Secondly, in dividing the foot into several separate segments, an assumption is made that several of the individual bones of the foot do not move relatively to each other, and there is evidence that this is unlikely [8]. Measurements based on this assumption either miss important kinematics between bones, or attribute motion to one joint when it actually occurs at another, which has not been measured. Finally, descriptions of foot and ankle kinematics may be incomplete because not all foot bones are included in the measurements. This is particularly the case for the talus, which is inaccessible in vivo without an invasive approach.

To avoid some of these pitfalls an invasive in vivo approach has been used in several studies [6], [9], [10], [11], [12], [13], [14]. However, these data have been limited to assessment of the tibia, talus and calcaneus during walking/running and have not assessed the mid or forefoot. Cadaver models are an alternative [8], [15], [16], [17], [18], [19] but these inevitably involve some compromise in the extent to which in vivo gait can be replicated. The aim of this work, therefore, was to provide high quality in vivo kinematic data to describe rear, mid and forefoot kinematics during walking. The following bones were studied: tibia, fibula, talus, calcaneus, navicular, cuboid, medial cuneiform, first and fifth metatarsal.