has part has part characteristic of has modifier Joint hypermobility Synonyms of joint hypermobility (JH) include joint laxity and double-jointedness. In general terms, joint hyperlaxity is often considered a further synonym of JH. JH may be caused by a number of factors including intraarticular disease and injury or slacking of extraarticular structures such as joint capsules, ligaments, and muscles. Establishing whether a joint is hypermobile or not is a relatively easy task and it is carried out by (i) using professional tools, such as the orthopedic goniometer; (ii) following specific procedures; and (iii) comparing the measured range of motion (ROM) with normal parameters. When JH is observed at one or a few types of joints (usually fewer than five) it may be defined as localized joint hypermobility (LJH). Typically, LJH affects a single small or large joint and may be bilateral (e.g., bilateral genu recurvatum due to knee hyperextensibility). LJH may be inherited, but it may be an acquired trait related to, for example, past trauma, joint disease, surgery, or training (e.g., spine hypermobility). In individuals with JH at multiple sites (usually five or more), the term generalized joint hypermobility (GJH) is preferred. Abnormality of joint mobility abnormal increased mobility skeletal joint