Repeatability of a multi-segment foot protocol in adult subjects

Despite the numerous protocols for multi-segment kinematic analysis of the foot, the literature is scarce regarding relevant measures of reliability. The aim of the present work was to assess the inter-trial, inter-session and inter-examiner variability of one of these protocols by an established method. The kinematics of the joints of the foot of two volunteers were analyzed by four examiners with different degrees of experience in three sessions, two-to-four weeks apart. In each session the data of five trials of level walking were collected and the rotations in the three anatomical planes between foot segments were calculated. The mean value over stance phase duration of the standard deviation of these rotations was calculated for groups of trials according to the statistical method as in Schwartz et al. [6]. For each rotation, the inter-examiner variability was larger than the inter-session, and the latter larger than the inter-trial. The inter-session variability was found in the same order of magnitude for standard lower limb protocols for the two expert examiners, but much higher for the inexperienced examiners.