Catcher's Knee Wedges or Knee Savers are very important to help prevent knee strain.

Catchers of all ages should wear the Knee Wedges or Knee Savers, which are worn behind and in the crook of the flexed knee. The knee wedges support some of the body weight above the knee and cushion the area behind the knee joint while the catcher is in a crouched position, minimizing excessive knee strain and significantly reducing risk of knee injury (no controlled studies to this date provide proof of reduced knee injury risk, but the weight bearing change on the knee joint is obvious). The wedge-shaped pads are worn behind the knee and provide support between the upper calves and the lower hamstrings. They prevent extreme flexion of the knee joints and support some of the body weight that bears down on the prolonged flexed knees that are required in the catcher's crouched position during a baseball game.

Ligaments and cartilage of the knee are subject to harmful forces when catchers sit in their crouched positions with hyperflexed knees and no protection or support. The full body weight on a hyperflexed knee transmits high compressive forces on the internal tissues of the knee. Full body weight also causes distraction forces in front of the fulcrum of the knee joint when the full weight of the upper body is bearing down on the femur as a lever holding the upper body weight.

The device also relieves some of the prolonged isometric quadriceps tension required to support the upper body weight during the catcher's crouch, preventing excessive fatigue of the quadriceps. The prevention of fatigue of the quadriceps muscle could improve the performance of reaction time to get out of the crouched position to get up and sprint to catch pop-ups and foul balls.