ELBOW JOINT FORCES IN PATIENTS WITH RHEUMATOID ARTHRITIS

Whilst developing an elbow endoprosthesis, the joint forceswere estimated for patients with rheumatoid arthritis. Elbowflexion strength of rheumatoid patients was found to be 45 %of normal. Muscle strengths and limb geometry data were foundby a dissection technique, which allowed joint forces to becalculated during flexion, extension and abduction efforts.Forces up to 2.4 kN were predicted to act on the distal humerus,with similar forces acting in both radius and ulna. The skeletalstructure is well adapted to carry the predicted forces, andonlay-type prostheses are recommended for elbow replacement. _*Paper read at the Annual Meeting of the British Associationfor Rheumatology and Rehabilitation, London, April 1979.