It has been found over the last number of years that the best method of performing the crunch or sit up exercise is through a very short range of motion. Every exercise has a full range. For example a bicep curl has a defined start and finish, or bottom and top position. Just as with all other exercises, the crunch also has the start and finish position. It is only a 6”s motion to the contraction or ending point. Most people don”t realize this, but that is it any additional motion puts undue strain on the lower back.The Powertec maxi crunch was designed to take you though that short motion. The hand grip is positioned above you for comfort during the exercise and this position forces the resistance on the abs to do the work.There is also a comfortable head pad that moves with you to provide support to the neck. Lastly the adjustable angle pad is set so it takes any pressure off of the lower back at the start of the exercises and puts immediate resistance on the abs.Very simple yet highly effective, and what a price for a health club quality machine.