Stretching- Keeping range of motion- Using the BIOTRON™ to stretch prior to or after an exerciser set can produce long term results in flexibility/range of motion. To properly stretch a muscle, it needs to be relaxed. When trying to stretch muscles using weights, a muscle contraction is required to support the load. Since the BIOTRON™ has no live load it enables stretching with total relaxation of the target muscles.- the key to effective stretching.