20 shoulders affected by rotator cuff pathology and 20 healthy shoulders were included.
The tested arm was positioned using various straps and orthoses to help the participants not to use muscular activity unless directed to. Intramuscular electrodes were inserted to measure rotator cuff activities and a real time ultrasound was used to measure the GHJ translation.
A hand held dynamometer was used to place the various forces to cause GHJ translation with the shoulder in various positions in relaxed or resisted into an internal or external rotation.
The study revealed increased posterior translation in the pathology group in the abducted and neutral positions. It was also found that, when the posterior translation force was applied, there was reduced muscle activity in the supraspinatus and upper infraspinatus muscles.
The study concluded that GHJ stabilization lacked in the pathology group compared to the control group.
> From: Rathi et al., J Sci Med Sport 21 (2018) 885-889 . All rights reserved to Elsevier Ltd. Click here for the online summary.
