Squatting down and getting up with pain inside the bend of the leg, the possible causes are knee meniscus posterior horn injury, soft tissue injury, osteoarthritis, popliteal cysts and so on. 1. Posterior horn of knee meniscus injury: squatting down and getting up with pain inside the leg bend may be due to the posterior horn of knee meniscus injury. 2. Soft tissue injury: if the ligaments, joint capsule and other soft tissues in the leg bend area are damaged, the symptom of squatting down and getting up with pain in the leg bend will also occur. 3. Osteoarthritis: due to the degeneration of the knee joint, there is destruction of articular cartilage, bone friction when the knee joint bends under load, resulting in squatting down and getting up inside the leg bend pain. 4. Popliteal cyst: the deep bursa of the popliteal fossa is enlarged, causing pain and swelling at the back of the knee, and the phenomenon of squatting down and getting up with a pain in the bend of the leg. Squatting up leg pain may also have other reasons, if the persistence of unrelieved, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment, so as to avoid delaying the condition.