Widespread periarticular new-bone formation (myositis ossificans) was studied in 45 patients with brain damage who were in long-term coma. Thirty-six of these patients displayed myositis ossificans around at least one major joint. The development of myositis ossificans was shown to be independent of the sex and age of the patient and also of the aetiology, duration and outcome of the coma. Radiographic evidence first appeared between one and two months after the onset of coma. The maximal spread of myositis ossificans was reached in the first five months after the onset of coma. Progression of the disease was not observed after 14 months. Myositis ossificans was defined as a progressive self-limiting disease found in comatose patients.

1. Three cases of paralysis of the radial nerve after intensive muscular effort in extension of the elbow are described. Clinical and electrophysiological evidence is recorded.

2. There was motor and sensory affection of varying degree and extent in the distribution of the radial nerve.

3. The type of lesion in each case was that of neurapraxia, and rapid spontaneous recovery occurred in each case.

4. The level of the lesion was in the arm, below the origin of the branches to the triceps.

5. The cause of the lesion was thought to be compression by a fibrous arch related to the lateral head of the triceps.

6. The cases are discussed in relation to other instances of compression of nerves by fibrous arches, and an explanation is advanced for spontaneous recovery.