Article

OBJECTIVE: To characterize scapular kinematics and shoulder muscle activity in
patients with subacromial impingement syndrome, with and without visually
identified scapular dyskinesis. DESIGN: Cross-sectional study. PARTICIPANTS: Participants with subacromial impingement syndrome
(N=38) were visually classified using a scapular dyskinesis test with obvious
scapular dyskinesis (n=19) or normal scapular motion (n=19). INTERVENTIONS: Not
applicable. MAIN OUTCOME MEASURES: An electromagnetic motion capture system
measured 3-dimensional kinematics of the thorax, humerus, and scapula.
Simultaneously, surface electromyography was used to measure muscle activity of
the upper, middle, and lower trapezius; serratus anterior; and infraspinatus
during ascending and descending phases of weighted shoulder flexion. Separate
mixed-model analyses of variance for the ascending and descending phases of
shoulder flexion compared kinematics and muscle activity between the 2 groups.
Shoulder disability was assessed with the Pennsylvania Shoulder Score (Penn).
RESULTS: The group with obvious dyskinesis reported 6 points lower on Penn
shoulder function (0-60 points), exhibited a main group effect of less scapular
external rotation of 2.1 degrees during ascent and 2.5 degrees during descent,
and had 12.0% higher upper trapezius muscle activity during ascent in the 30
degrees to 60 degrees interval. CONCLUSIONS: Patients with obvious dyskinesis and
subacromial impingement syndrome have reduced scapular external rotation and
increased upper trapezius muscle activity, along with a greater loss of shoulder
function compared with those without dyskinesis. These biomechanical alterations
can lead to or be caused by scapular dyskinesis. Future studies should determine
if correction of these deficits will eliminate scapular dyskinesis and improve
patient-rated shoulder use.
CI - Copyright (c) 2015 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS