However, if you sleep with your legs arched while lying flat, you need to contract the flexor muscles of the lower limbs to maintain the flexion posture of the lower limbs in addition to increasing the patellofemoral pressure of the knee joint. Long-term fixed posture will lead to decreased blood circulation of muscle tissue, lactic acid accumulation and aseptic inflammation of lower limbs, resulting in pain symptoms. Therefore, it is not recommended for patients to sleep in this position.
If you sleep on your side, your legs are bent and your knees are arched, and the effect is often not obvious. However, there is some pressure between the patella and the femoral scapula. Long-term compression of cartilage will lead to early degeneration and prone to osteoarthritis. This sleeping position is not recommended for patients.