Once the frequency of 18 Hz was reached, the feet were gradually placed wider apart until they were vertically below the hip joint. Thus, the middle toe of each foot was eventually placed between 8 cm and 11 cm from the neutral axis of the vibration plate, depending on the width of the child’s pelvis. Whether using the tilt table or the ground-based WBV system, the patients flexed their knees and hips between 10 and 45 degrees (to prevent the vibration from extending up to the head). Guided by the study physiotherapist, the patients shifted their weight from side to side or increased and decreased the knee and hip angle. Other exercises included weight shift with rotation of the trunk, and alternate flexion and extension of knees. Postural correction was encouraged through visual feedback (by performing the treatment in front of a mirror) and through the therapist‘s verbal cueing. Treatment adherence was calculated as the ratio between the total time of WBV treatment received and the time of WBV exposure scheduled as per study protocol.