The contribution of the scapula to active shoulder motion and self-assessed function in three hundred and fifty two patients prior to elective shoulder surgery.

PURPOSE: Scapular motion is an important component of shoulder function. This study determined the contribution of the scapula to active shoulder motion in control subjects and patients with loss of shoulder function.

METHODS: The Kinect system was used to assess active scapulothoracic (ST) and humerothoracic (HT) abduction in 12 controls and in 352 patients before elective shoulder surgery.

RESULTS: For the controls, ST abduction averaged 26 ± 7° or 19% of the active HT abduction (135 ± 5°). For the 352 patients having elective surgery, active ST abduction averaged 12 ± 10°, or 17% of the active HT abduction (72 ± 38). For 10 of the 12 SST functions, patients unable to perform the function had significantly less scapulothoracic abduction, e.g., shoulders unable to lift one pound to shoulder level had 9 ± 8° of ST abduction in contrast to 17 ± 10 for those able to perform this function (p < .001).

CONCLUSIONS: Scapulothoracic motion is an important component of active shoulder motion and function in both healthy shoulders and in those compromised by common pathologies. This study suggests that rehabilitation directed at improving active scapulothoracic motion may improve the function of shoulders with loss of glenohumeral motion.

LEVEL OF EVIDENCE: Level III Prognostic Study.