Effect of Arm Position on Visualization of Target Zone for Posterior Glenohumeral Joint Injection

Objectives: Glenohumeral injections can be performed using a variety of approaches. We hypothesize that the position of the ipsilateral arm affects the target zone for posterior approach of glenohumeral joints. Material and Methods: We performed ultrasound on three volunteers with arm with in neutral and varying degrees of flexion and extension. Results: We found that target zone is increased on flexion and decreased with arm in extension. Conclusion: Considering patient comfort, target zone, and operator ergonomics, we conclude that the posterior glenohumeral US-guided injections should be performed with patient lying on the contralateral side with the ipsilateral arm in neutral, and hand rested on the thigh (Birmingham Royal Orthopedic Hospital (BROH) position).