 Objective: The primary objective of this study is to investigate whether protraction of the pelvis at the affected side is a compensatory mechanism to reduce out-toeing and thereby improve foot positioning and restores the gait pattern towards a normal gait pattern in patients with unilateral stable SCFE, treated with single screw in situ fixation. Dynamic postural balance will be analysed as well since an altered, waddling gait, is observed in patients with treated SCFE. In addition, activity patterns of lower limb muscles will also be evaluated using surface electromyography. Kinematic and EMG data of patients will be compared with data of healthy controls with no gait pathology in order to investigate these objectives. 