Ultrasonographic Validity of Clinical Shoulder Impingement Signs in Patients Without Limitation of Motion.
Na Yoon Yoo, Hyoung Seop Kim
PMID 41477065WHAT IT FOUND
In patients with painful shoulder impingement signs but full motion, ultrasound showed no difference in supraspinatus tendon thickness between the painful and pain-free side.
This challenges mechanical impingement as the primary pain source, suggesting early-stage inflammation or capsulitis instead.
Key findings
01Supraspinatus tendon thickness did not differ significantly between the painful and non-painful shoulders, nor between left and right sides.
02All participants reported a painful arc, but positive results on specific impingement tests (Neer, Hawkins-Kennedy, Paxinos, horizontal adduction) were found in a minority of patients.
03Pain and disability scores improved significantly two weeks after ultrasound-guided intraarticular steroid injection, though the study was not designed to test this therapeutic effect.
STILL TO COME
How it was doneWhat they foundWhat it means for PTsWhat it means for OTs
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What it does not show
Very small sample size (n=27) limits statistical power and generalizability. Single-center study with ultrasonography and injections performed by one specialist, introducing potential bias. The study was not designed to evaluate the therapeutic efficacy of steroid injections, so pain improvements cannot be definitively attributed to the injection alone without a control group. No long-term follow-up; outcomes were assessed only at 2 weeks.
Declared interests
The investigators have no financial or nonfinancial disclosures to make in relation to this project.
The easy way to misread this
Do not interpret the significant pain reduction after steroid injection as proof that the injection is the required treatment or that mechanical impingement was the cause. The study lacked a control group for the injection, and the primary finding was that tendon thickness did not differ between painful and pain-free sides, challenging the mechanical impingement hypothesis.
Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →