Quadriceps strengthening is commonly suggested because the quadriceps muscles help to stabilize the patella. Those muscles include the hamstrings, quadriceps, and calf muscles. In the knee the quadriceps and patellar tendon can sometimes tear. The tendon of the quadriceps femoris muscle attaches to the base of the patella. It can rupture resulting in quadriceps tendon rupture. The vastus medialis is part of the quadriceps muscle group. The rectus femoris, a large muscle in the quadriceps, is typical. The femoral nerve passes through the muscle and innervates the quadriceps, pectineus, and sartorius muscles. All four quadriceps are powerful extensors of the knee joint. Exercises can strengthen the muscles around the knee, especially the quadriceps. The quadriceps and forearm muscles are usually affected early on. A wall sit is an exercise done to strengthen the quadriceps muscles. Tentative evidence supports exercises involving eccentric muscle contractions of the quadriceps on a decline board. Strengthening exercises should be performed after pain has subsided, on calves, quadriceps and gluteals. There is no interneuron in the pathway leading to contraction of the quadriceps muscle.