Joint hypermobility--asset or liability? A study of joint mobility in ballet dancers.

Much interest has been focused on generalized joint hypermobility in recent years with particular reference to its possible adverse sequelae. Though a feature of many hereditary disorders of connective tissue (listed in Table I), generalized joint laxity may occur apparently in the absence ofother abnormalities and probably represents the upper end of a spectrum of the range of normal joint mobility. Lack of precise criteria has hindered attempts to ascertain the incidence of joint hypermobility in a normal population. The term 'hypermobility syndrome' was devised by Kirk, Ansell, and Bywaters (1967) to describe this entity when it is the cause of musculoskeletal complaints.