Our spring-assisted technology absorbs impact and returns positive energy to assist the user. The crutch is designed to support good posture and the ergonomic handgrips keep the wrist in a natural position avoiding the kinking that occurs with traditional crutches. The Short In-Motion Forearm is as follows - Floor to Handle adjusts from 28 to 40 with 13 different height positions. The forearm cuff also has 4 height positions to allow the cuff to be in a comfortable position. For sizing Grip a pen or pencil in your hand. Standing upright with good posture measure from the floor to the pen or pencil gripped in your hand. Using this measurement look at the range of handle heights between the short and tall forearm crutches wherever your measurement falls is the crutch size you should use.