Some patients cannot cross their legs for specific reasons such as knee diseases and hip diseases, as follows: a. Knee diseases: Patients with knee diseases, such as osteoarthritis of the knee and meniscus damage, patients will have significant limitations in knee flexion and knee rotation, accompanied by severe pain, and therefore cannot cross their legs. X-rays and MRIs can reveal joint space narrowing, articular cartilage degeneration, and even meniscal damage. Second, hip joint diseases: patients suffering from hip joint diseases, such as osteoarthritis of the hip joint, ischemic necrosis of the femoral head, local acetabular fracture, etc., can cause patients to be unable to cross their legs, and patients will have hip joint pain and limited activities. X-rays and MRI can reveal fractures, acetabular labral tears, and ischemic necrosis of the head of the femur. Therefore, the above-mentioned patients cannot perform cross-legged movements, and cross-legged will aggravate the condition and is not conducive to recovery.