Ankylosing spondylitis can cause heel pain because ankylosing spondylitis is an autoimmune disease that mainly invades the sacroiliac joints and spine. DR films show bamboo-like changes in the spine, and changes in the spine can cause nerve root compression, resulting in heel pain, limited movement, and numbness, etc. Nerve root compression can usually be found there by CT or MRI, and the diagnosis is usually clear. The vast majority of patients with ankylosing spondylitis will develop osteoporosis, which can be relieved by active treatment of heel pain, so ankylosing spondylitis should be treated actively to get better results.