The most effective concise quadriceps training method The quadriceps muscle is vital to maintain the stability of the knee joint, reduce knee pain and promote recovery from knee injuries. When knee diseases, injuries and after surgery, the quadriceps muscle is easily atrophied in a short period of time due to injuries, and after atrophy, it is difficult to recover and requires scientific and reasonable, persistent training to prevent the quadriceps and promote The recovery of muscle strength. Quadriceps muscle strength training is mainly suitable for the following cases: after knee replacement, after internal fixation surgery of fracture in the knee area, after meniscal injury or surgery, osteoarthritis of the knee joint and synovitis of the knee joint.