My thigh and buttock are very painful following an over-enthusiastic massage eight weeks ago and I have been diagnosed with myositis ossificans. I am an energetic and fit 65-year-old, who likes trekking over hills and moors and would be grateful for any information about treatment and outcome of this condition.

Myositis ossificans (MO) is the formation of bone in a muscle, commonly in the thigh or arm and more rarely in the chest and the buttocks. Though MO can develop following a soft tissue injury such as a fracture or a dislocation, or after surgery, it sometimes pops up following ischemia (inadequate flow of blood to a part of the body) or inflammation. It is unlikely to be caused by an over-zealous massage, though this could exacerbate a hidden problem. Classically, there is pain, tenderness, swelling and decreased range of motion in the joints affected. But it is difficult to diagnose because, mostly, MO does not produce extraordinary symptoms - it is often spotted by accident from radiographs obtained for unrelated problems.

The jury is still out on how to manage the condition. Many authorities recommend reducing motion immediately after diagnosis for up to one month, and then gradually increasing exercise. Some people prescribe painkillers, along with other supportive measures. Sometimes, surgery to remove the bone may be the answer. However, this should be undertaken only after the lesion has stopped producing bone: this can take up to two years, and the surgery can produce further areas of MO. A diagnosis cannot be made just based on clinical examination, and radiographs are necessary. It is possible that MO is not the cause of your symptoms: other conditions are inflammatory conditions, sciatica or back problems. You can take paracetamol for the pain, but you may need referral to an orthopaedic surgeon.

· Professor Maffulli is a consultant surgeon at Keele University medical school. If you have a question, email fitness@theguardian.com