Shape Twin Ball New Logo Hardly used, in clean condition. Please check the images for the condition. No box included. The adductor muscles are important for balancing the pelvis. Standing with your legs closed stimulates the adductors, which lifts the pelvis. Furthermore, vibrating in that position stimulates the pelvic floor muscles (which work with the adductors) and the abdominal muscles (transverse abdominis), leading to an ideal balance. Not just for training, but also for body care. This single device supports 20 types of stretches.