title: Scapular-Positioning Patterns During Humeral Elevation in Unimpaired Shoulders.
abstract: OBJECTIVE: To assess scapular-positioning patterns using a static measurement technique. DESIGN AND SETTING: We used a 4-within-factor design to compare scapular upward rotation among subjects. The within factors included side (dominant, nondominant), plane of motion (scapular, sagittal), direction of motion (ascending, descending), and level of humeral rotation (rest, 30 degrees, 60 degrees, 90 degrees, 120 degrees ). SUBJECTS: Twenty-seven subjects with unimpaired shoulders. MEASUREMENTS: We measured scapular position and glenohumeral range of motion using a digital inclinometer and goniometer, respectively. All measurements were performed bilaterally. RESULTS: Between-session repeatability was poor to excellent depending on humeral-elevation angle. The scapular plane demonstrated significantly more scapular upward rotation than did the sagittal plane at 120 degrees of humeral elevation. CONCLUSIONS: The scapula demonstrated a consistent pattern of downward rotation initially from rest to 30 degrees of humeral elevation, followed by an upward rotation after 30 degrees of humeral elevation to the highest level (120 degrees ). Scapular upward rotation is greater in the scapular plane than in the sagittal plane. Therefore, overhead rehabilitation exercises should be performed in the scapular plane, especially in subjects with rotator cuff tendinopathy.
authors.affiliation: University of Michigan, Ann Arbor, MI.
authors.forename: Paul A.
authors.initials: PA
authors.lastname: Borsa
authors.forename: Mark K.
authors.initials: MK
authors.lastname: Timmons
authors.forename: Eric L.
authors.initials: EL
authors.lastname: Sauers