The Heidelberg foot measurement method: development, description and assessment

The aim of this study was to develop and evaluate a kinematic measurement method for the foot that could be applied clinically to measure foot function including all typical foot deformities. The ankle was modelled as two anatomically based hinge joints rotating around anatomical axes estimated by the use of projection angles. For the mid- and forefoot a descriptive approach was chosen by defining angles between anatomical landmarks or reference points derived from these landmarks. The motion of 17 markers on the lower leg and foot was measured during walking gait on 10 adult participants with no known abnormalities to determine the pattern of normal foot motion, assess reliability and provide a reference against which pathological foot behaviour could be compared. Functional angles for mid- and forefoot motions were developed to improve clinical applications of the data. The combination of anatomically and technically oriented marker placement on the foot is a reliable basis for reproducible kinematic measurements and the method was shown to be viable for clinical practice.