Body-Solid engineers knew that the best way to build an explosive lower body, and stay that way, would be to make your workouts incredibly Powerful... Comfortable... and Safe. As you work your quads, glutes, and calves, the engineered smoothness of the Leg Press / Hack Squat Machine spares your bones and joints. Three lockout positions are under the user's control throughout the exercises and provide user safety and the option of different start / stop positions.