Leg and knee socket pain can be associated with popliteal cysts, popliteal bursitis, and ligament injuries. 1. Popliteal cyst: Minor injuries to the localized bursa and the semitendinosus muscle, the medial head of the gastrocnemius muscle, or friction between the musculotendinous portions of the gastrocnemius and semimembranosus muscles can lead to popliteal cysts and cause symptoms of leg and knee pain in the leg and knee fossa. 2. Popliteal bursitis: When the popliteal bursa is irritated by infection or trauma, it can cause synovitis, leading to symptoms such as leg and knee pain. 3. Ligament injury: when patients have ligament injuries such as cruciate ligaments, it can lead to symptoms of pain in the leg and knee sockets, and in severe cases, it can lead to limitation of activities. There are many reasons for knee pain, so it is recommended to go to the hospital in time for early treatment after completing the relevant examinations.