Does the combination of pain and dyskinesis alter scapular kinematics during shoulder elevation with and without elastic resistance?

Abstract

Background: The relation between shoulder pain and scapular movement impairments is still unclear. The scapular assistance test (SAT) assesses the influence of shoulder pain on abnormal scapular movement or positions. This study aimed to investigate scapular kinematics during arm raising/lowering with and without elastic resistance in volleyball players with positive and negative SAT.

Methods: Scapular kinematics of twenty-six volleyball players with Scapular Dyskinesis (13 positive SAT, 13 negative SAT) was measured during shoulder abduction, flexion, and scaption under loaded and unloaded conditions. 3D scapular kinematics were recorded using Vicon motion capture system by an Acromial Marker Cluster.

Results: The main findings revealed that in the unloaded condition, participants with a positive SAT showed significant decrease in scapular posterior tilt in 60-90 degrees of arm raising in the scapular plane, compered to negative SAT.

Conclusions: It can be concluded that the combination of pain and dyskinesia may alter scapular posterior tilt during shoulder elevation in scapular plane without elastic resistance; but this does not alter the scapular upward and external rotation.

Keywords: Dyskinesia; Elastic resistance; Pain; Scapular assistance test; Scapular kinematics.