Abstract
Background
Subacromial impingement syndrome (SIS) is a common cause of shoulder pain and functional limitation in overhead athletes, particularly volleyball players. Although corticosteroid injections provide short-term pain relief and mobilization improves shoulder mechanics, evidence comparing their combined effect with mobilization alone in young athletic populations remains limited, particularly with respect to radiological outcomes.
Objective
To compare the effects of corticosteroid injection combined with mobilization versus mobilization alone on pain, shoulder function, range of motion, and radiological outcomes in university volleyball players with SIS.
Methods
This prospective randomized controlled trial included 60 male university volleyball players (18–25 years) with clinically diagnosed SIS. Participants were randomly allocated to receive either a single subacromial corticosteroid injection followed by a standardized mobilization program (
n
= 30) or mobilization alone (
n
= 30). Outcomes were assessed at baseline, 4 weeks, 8 weeks, and 6 months and included pain intensity (VAS, primary outcome), pain pressure threshold, shoulder range of motion, and functional disability (SPADI) as key secondary outcomes, and radiological measures (coracohumeral interval, supraspinatus tendon thickness, and subacromial bursa thickness) as exploratory outcomes. Intention-to-treat analysis and effect sizes were calculated.
Results
Both groups demonstrated significant improvements over time; however, the combined intervention group showed significantly greater and earlier improvements in pain, function, and shoulder mobility (
p
= 0.001). Pain intensity (VAS) decreased significantly more in the combined intervention group, with a between-group mean difference of 2.6 points at 6 months (95% CI: 2.31 to 2.88), favoring the combined group. Pain pressure threshold increased significantly, with a between-group difference of 25.2 kPa at 6 months (95% CI: 8.6 to 41.8). Between-group differences exceeded minimal clinically important difference values for pain and SPADI, with moderate to large effect sizes. Radiological outcomes demonstrated greater increases in the coracohumeral interval and greater reductions in tendon and bursal thickness in the combined group at 6 months.
Conclusion
Corticosteroid injection combined with mobilization provides superior and clinically meaningful improvements in pain, function, shoulder mobility, and radiological outcomes compared with mobilization alone in university volleyball players with SIS. This multimodal approach appears effective for managing SIS in high-demand overhead athletes. The imaging findings should be regarded as exploratory and supportive of improved subacromial mechanics rather than as evidence of definitive structural recovery.
Clinical Trial Registration
identifier CTRI/2020/06/025692.