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Updated: May 8, 2026

Measuring 3D In-vivo Shoulder Kinematics using Biplanar Videoradiography
Published on: March 12, 2021
Impact of Coracoacromial Ligament Thickness on Shoulder Impingement Syndrome: A Cross-Sectional Magnetic Resonance
Pooneh Dehghan1,2, Seyedhassan Langari1, Fatemeh Ghiasi1
1Department of Imaging, School of Medicine, Taleghani Hospital Shahid Beheshti University of Medical Sciences Tehran Iran.
Background And Aims:
Shoulder impingement syndrome (SIS) is a common cause of shoulder pain and dysfunction. This study explored the association between coracoacromial ligament (CAL) thickness and SIS using magnetic resonance imaging (MRI).
Methods:
This cross-sectional MRI-based observational study involved 47 patients aged 18-70 years with shoulder pain. T2 fat-saturated sagittal MRI views were used to measure CAL thickness at proximal and distal portions by two radiologists. Statistical analyses included t-tests, χ 2 tests, and Pearson's correlation, with significance set at p < 0.05.
Results:
Mean proximal CAL thickness was 1.24 mm (SD = 0.44 mm), and distal thickness was 1.50 mm (SD = 0.72 mm). Patients with SIS had significantly greater thickness at proximal (1.36 mm vs. 1.05 mm, p = 0.002, d = 0.82) and distal (1.78 mm vs. 1.12 mm, p = 0.001, d = 0.92, 95% CI: 0.39-0.93). Males showed greater distal thickness (1.62 mm) than females (1.34 mm, p = 0.04, d = 0.45). Age did not correlate with thickness (p > 0.71). Subacromial bursitis (70.21%, p < 0.001) and acromioclavicular (AC) joint osteophytes (68.09%, p = 0.003) were prevalent and associated with SIS.
Conclusion:
CAL thickness, particularly at the distal portion, was strongly associated with SIS, independent of age but varying by gender. Measuring CAL thickness may aid SIS diagnosis.

