Evaluating Displacement of the Coracoacromial Ligament in Painful Shoulders of Overhead Athletes Through Dynamic Ultrasonographic Examination

Wu C-H, Wang Y-C, Wang H-K, Chen W-S, Wang T-G. Evaluating displacement of the coracoacromial ligament in painful shoulders of overhead athletes through dynamic ultrasonographic examination.

Objective

To evaluate displacement of the coracoacromial ligament (CAL), using dynamic ultrasonography (US), for detecting instability-related impingement caused by overhead activities.

Design

Between-group survey.

Setting

Department of Physical Medicine and Rehabilitation in a tertiary care center.

Participants

Volunteer high school volleyball players with unilateral shoulder pain (n=10) and volunteer asymptomatic high school volleyball players with identical training activities as control subjects (n=16).

Interventions

Not applicable.

Main Outcome Measure

The displacement of the CAL was measured during throwing simulation using dynamic US. Both shoulders of all subjects were evaluated.

Results

During throwing simulation, the displacement of the CAL in the painful shoulders of overhead athletes increased significantly greater than the displacement in the asymptomatic shoulder (3.0±0.7mm and 2.2±0.4mm, respectively; P=.017). No difference was identified between the displacements of the CALs of bilateral shoulders of the control group subjects.

Conclusions

Dynamic US, by measuring the displacement of the CAL during simulation of throwing, may be helpful in detecting abnormal humeral head upward migration in overhead athletes.