Range3D uses the method of passive static stretching whereby the stretch is held for a prolonged period by external means. Each exercise starts from a neutral position, making Range3D suitable for all levels of flexibility. The user can progress up to the normal range of motion, and beyond if necessary. There is a smooth transition from one exercise to the next with no adjustments needed in between.
The user adjusts the head rest and leg supports according to height, ensuring the body will be aligned with the pivot points. The sliding ankle support accommodates variations in lower leg length and cups the heel to prevent the foot moving. Access is from a footplate at the front, allowing the user to sit within the leg supports which are bent at the knee. The leg straps are fastened first and the waist grips are tightened once the user is lying back. The body is now fully supported, and the pelvis and non-stretching leg will be kept still during the exercises.
There are two handles to move each leg support, providing the user with leverage in every exercise position. The handles for vertical movement are geared so that the leg supports can be raised easily, and dampers ensure they are lowered safely. The user switches on a ratchet before moving a leg support and the 2° or 3° intervals provide fine control at the limit of stretch. The ratchet will maintain the stretching tension for as long as required. The leg can then be either moved further into the stretch or returned to neutral once the ratchet is switched off.
The leg supports rotate about axes which coincide with the hip joint, enabling the true range of motion for each exercise to be accurately measured. Calibrated position sensors produce an electronic output which is displayed digitally. A “hold” feature allows the reading to be retained until the same exercise has been performed with the other leg. The ranges of motion can also be compared with previous values and with population norms. The display console includes a timer to measure the duration of the stretch.