Exerciser replaces free weights with fiberglass

The poles make up a compliant mechanism that transfers motion, force, or energy without using movable joints. Unlike other exercisers that let users work against resistance, Y-flex's compliance technology simulates the feel of constant free weights throughout the exercise. Machines that use flexible arms or uncoiled springs increase resistance the more the bar is lifted or moved.

The workout machine should be less expensive and simpler for manufacturers to produce and assemble, according to engineering professor Larry Howell. He also believes Y-flex is precise and reliable, which should reduce wear and maintenance.