TY - JOUR T1 - A new classification system for shoulder instability JF - British Journal of Sports Medicine JO - Br J Sports Med SP - 341 LP - 346 DO - 10.1136/bjsm.2009.071183 VL - 44 IS - 5 AU - John E Kuhn Y1 - 2010/04/01 UR - http://bjsm.bmj.com/content/44/5/341.abstract N2 - Glenohumeral joint instability is extremely common yet the definition and classification of instability remains unclear. In order to find the best ways to treat instability, the condition must be clearly defined and classified. This is particularly important so that treatment studies can be compared or combined, which can only be done if the patient population under study is the same. The purpose of this paper was to review the problems with historical methods of defining and classifying instability and to introduce the FEDS system of classifying instability, which was developed to have content validity and found to have high interobserver and intraobserver agreement. ER -