Background: The increasingly popular sport of rock climbing is an activity which predisposes participants to overuse injuries. The unique physical demands associated with climbing, as well as a reported 33%-51% incidence of shoulder injuries in these athletes is suggestive of abnormalities in scapulohumeral biomechanics.
Objective: To examine the glenohumeral to scapulothoracic (GH:ST) ratio, as represented by end range static positions (ERSP) of the scapula and humerus, in a group of rock climbers and compare it to a group of non-climbers.
Methods: The GH:ST ratio of twenty-one experienced rock climbers was compared with 40 non-climbers using a bubble inclinometer to measure scapular upward rotation at the subjects' maximum glenohumeral elevation.
Results: As represented by ERSP, rock climbers had a significantly greater GH:ST ratio than non-climbers. The mean ratio of climbers was 3.7:1 compared with non-climbers at 2.8:1. Scapulothoracic motion appeared to be the source of this difference.
Discussion and conclusion: A possible explanation for this difference could be related to the extreme and prolonged positioning associated with rock climbing maneuvers that result in shoulder musculature imbalances in strength and flexibility.