To include patient after traumatic (calcaneal) fractures for this study. They can be included to analyze gait with the OFM foot model, a non invasis model. Patient will be invited to the movement laboratory of the MUMC. Markers will be detached with dubble sided tape on anatomical points. After that gait will be recorded with infra-red camera's and an animation model will be formed. With this model further analysis can be made to range of motion between different segement of the foot. These results will be compared with patient with an arthrodesis, healthy subjects, futher questionnaires, physical examination and radiographic findings will be correlated.

All subjects are asked to come to the movement laboratory of Maastricht University Medical Centre on one individual day. Before gait analyses the following characteristics were measured; height, weight, BMI, knee and ankle width (measured between the two condyles of the knee and the measured between the two malleoli of the ankle) and leg length . All measurements are performed by researchers who was trained in the examination of the foot. At least one static trial was performed with all 42 markers, with the subjects in stance phase in an anatomic neutral position. After calibrating the markers and calculating the subject-specific joint axes in the static trial, 6 markers were removed, according to the OFM protocol. After that the subjects were asked to walk barefoot in normal speed after a number of practice trials. For this speed at least 8 proper recordings were made during walking. The healthy subjects were also asked to walk in slow speed and 8 proper recordings were made during this slow-speed walking. One whole step was considered complete from heel landing (initial contact) to toe-off. A force plate was used to determine the heel-strike and toe-off phase during walking. Corrections in the axes of the knee and ankle were made if necessary and tiles were saved for further data output.

Inclusion Criteria:

• patients with foot and ankle fractures

Exclusion Criteria:

• concomitant surgery for fractures of contra lateral leg/ankle or pre-existent abnormalities of the lower extremities, neurotrauma, spinal or neurological injury, pathologic fractures and people dependent in activities of daily living

healthy subjects and patients after foot and ankle trauma fracture surgery