Left knee squatting directly after standing up like twisted multi-finger left knee joint instability, common causes are knee injury, osteoarthritis, chondromalacia patellae and so on. 1. Knee injury: knee ligaments and meniscus play an important role in the stability of the joint, if the ligament injury and meniscus injury, will lead to knee instability, the left knee squatting and then stand up like twisted. 2. Osteoarthritis: Degenerative lesions of the knee joint can lead to osteoarthritis, which mainly damages the articular cartilage and can cause instability of the knee joint. 3. Chondromalacia patella: after chronic damage to the softened surface of the patella, the cartilage can become swollen, invasive and other lesions, which can cause instability of the knee joint and appear as if the knee joint is twisted when standing up. The causes of left knee instability are more, if the symptoms continue to be unrelieved, it is recommended to consult a doctor in time to clarify the cause of the disease and carry out targeted treatment.