The hypermobility syndrome. Musculoskeletal complaints associated with generalized joint hypermobility.

This paper is concernedwith generalized joint laxity occurring as an isolated finding in otherwise normal subjects. We have used the name "Hypermobility Syndrome" for the situation in which this joint laxity is associated with musculoskeletal complaints. The range of joint motion varies considerably between individuals and with age, race, and body build. Where the joints are unduly lax and the range of motion is in excess of the accepted normal in most of the joints examined, we regard the subject as having generalized hypermobility. This is not uncommon in the general population. In their sample of 285 English schoolchildren, Carter and Wilkinson (1964) found excessive motion in at least four joint pairs in 7 per cent. and Sutro (1947) had shown that three or more joint pairs were hypermobile in 4 per cent. of 435 adult orthopaedic outpatients. Information on this condition as a cause of musculoskeletal complaints is scanty. In the first detailed report, Key (1927) described a family in which the father and several sons were hypermobile because of generalized ligamentous laxity. Relatively little disability resulted except that recurrent patellar dislocation occurred in a son and the father had developed osteo-arthritic changes in the knees, spine, and fingers by the age of 50 with a resulting reduction in mobility. The first case of congenital hypermobility of joints as an isolated phenomenon producing chronic recurrent symptoms to be recognized by one of us (E.G.L.B., 1950) has unfortunately been lost to follow up. Rowatt Brown and Rose (1966) have recently drawn attention to ligamentous laxity as one of the causes of precocious osteo-arthritis. Most reports have noted a strong familial tendency (Finkelstein, 1916; Key, 1927), the inheritance being apparently dominant with a variable degree of expression (Sturkie, 1941).