Glenohumeral Internal Rotation Deficit Affects Functional Rotator Strength Ratio in Adolescent Overhead Athletes. (original) (raw)

Context: Glenohumeral internal rotation deficiency (GIRD) and lower eccentric external rotator (ER) to concentric internal rotator (IR) strength (ER:IR) ratio have been documented as risk factors for shoulder injuries but there is no information whether GIRD has an adverse affect on ER:IR ratio in adolescent overhead athletes. Objectives: The aim of this study was to investigate the affects of GIRD on functional ER:IR ratio of the adolescent overhead athletes. Design: Cross-Sectional Study. Setting: University Search Laboratory. Patients or other participants: Fifty-two adolescent overhead athletes participated in the study. Main Outcome Measures: To determine the GIRD, the range of glenohumeral internal and external rotation motion was measured with the use of a digital inclinometer. An isokinetic dynamometer was used for the assessment of eccentric and concentric IR and ER muscle strength of the dominant and non-dominant shoulders. One way ANCOVA where sport type was set as a covariate was used to analyze the difference between athletes with and without GIRD. Results: After standardized examinations of all shoulders, the athletes were divided into 2 different groups, which were shoulders with GIRD (n=27) and without GIRD (n=25).