When you're ready to build muscular legs and stronger knee joints, the Leg Extension Machine is ready to help you meet your goals. The exceptionally strong mainframe combined with a specially contoured DuraFirm™ thigh pad and biomechanically exact movement pattern provide a smooth, solid feel and immediate response. Precise pivot point alignment and center-drive, variable resistance cam design deliver the smooth and powerful response you expect. Recumbent DuraFirm™ back pad adjusts for all-size users and eliminates lower back strain while allowing full range-of-motion. Pop pin adjustable foot pads assure proper alignment. Hold down grips provide ultimate stability for a worry-free workout. No compromises here, this machine was engineered to deliver strength, comfort and safety.