“…13,30 Sites of ectopic bone formation are tendons, fascia, aponeurosis, and skeletal muscles. 17,20,31 Diaphragm, extraocular muscles, or smooth and cardiac muscles are not affected by this disorder. 20,32 The affected individual usually presents progressive ossification of connective tissue, which causes a significant limitation of osteoarticular mobility, 25,26 more commonly of the hip, knee, shoulder and elbow, 16 with the patient being locked in a single position and even being unable to sit.…”