A New Device for Improving Foot Marker Alignment

Introduction: Most clinical gait laboratories employ a simplified, one-segment, single-vector foot model. Misalignment of the markers used to define the foot vector leads to inaccuracies and increased variability in the measurement of dorsi-plantar flexion, foot progression and ankle rotation angles. Errors and variability in these angles is a significant problem since these metrics are frequently used in diagnosis and treatment planning. In an internal quality assurance study conducted in 2001, we observed a higher than expected degrees of intraand inter-observer variability between staff physical therapists in foot progression and dorsiplantar flexion angles [1]. As a result of these findings, we designed and constructed a device to aid in proper alignment of foot markers.