For patients with pain in the left tendon of the knee; first, it is seen as a strain injury to the left tendon of the knee, causing significant swelling, pain, pressure and limitation of knee flexion and extension activities. Secondly, bone degeneration and osteophytes in the knee joint area can cause significant pain in the left tendon of the knee when moving around if the osteophytes irritate the left tendon of the knee. Lastly, it can be caused by strain and cold, especially when squatting, running and jumping activities, which can easily lead to excessive strain on the left side of the knee tendon, resulting in localized sterile inflammation and spasm and edema of the left side of the knee tendon, causing pain and pressure on the left side of the knee tendon, especially during squatting activities.