Ultrasound comparison of the effects of prehabilitation exercises and the scapular assistance test on the acromiohumeral distance

Abstract

Background: Prolonged participation in overhead sports creates shoulder muscle imbalances which eventually alter the efficacy of the shoulder stabiliser muscles and heighten injury risk, such as subacromial impingement syndrome. Objectives: The aim of this study was to determine if ultrasound is effective to measure the acromiohumeral distance (AHD) to compare the effect of the scapular assistance test (SAT) on the AHD with a prehabilitative exercise intervention programme in asymptomatic cricket players. Methods: Baseline testing on cricket players from the North- West University cricket squad (N=34) included AHD measurements performed by a sonographer at 0°, 30° and 60° humeral abduction angles respectively, with and without the SAT application. Players were then randomly assigned to an intervention and control group. The control group continued with their normal in-season programme, whereas the intervention group also performed shoulder stability exercises for six weeks. Results: The exercise intervention had a similar effect as the SAT on the AHD at 0o and 30o humeral abduction angles in the intervention group. The AHD measurements in the exercise intervention group indicated widening at all abduction angles after the six-week intervention period, whereas the AHD measurements in the control group were equal or smaller than baseline measurements without the SAT at 30o and 60o respectively. Conclusion: Exercise intervention has a similar effect on the AHD of asymptomatic cricket players compared to the SAT – especially in 0°and 30o of humeral abduction. Ultrasound can therefore be utilised to assist in identifying the risk of developing subacromial impingement syndrome (SIS) in asymptomatic overhead athletes by measuring the AHD at different angles of humeral abduction, without and with the SAT application.