“Patients with adhesive capsulitis were clinically evaluated to establish whether pain elicited by pressure on the coracoid area may be considered a pathognomonic sign of this condition. The study group included 85 patients with primary adhesive capsulitis, 465 with rotator cuff tear, 48 with calcifying tendonitis, 16 with glenohumeral arthritis, 66 with acromioclavicular arthropathy and 150 asymptomatic subjects. The test was considered positive when pain on the coracoid region was more severe than 3 points (VAS scale) with respect to the acromioclavicular joint and the anterolateral subacromial area. The test was positive in 96.4% of patients with adhesive capsulitis and in 11.1%, 14.5%, 6.2% and 10.6% of patients with the other four conditions, respectively.”
“The coracoid pain test could be considered as a pathognomonic sign in physical examination of patients with stiff and painful shoulder.”
“In conclusion, digital pressure over the coracoid area elicits pain in the vast majority of patients with adhesive capsulitis and, thus, it can be considered an easy and reliable clinical test for identifying patients with or without this condition. Based on its sensitivity and predictive values, it may represent a “cardinal test” for this condition.”
These authors are claiming that the “coracoid pain test” is useful for the diagnosis of frozen shoulder. I think they are mistaken, and here’s why:
Adhesive capsulitis (aka frozen shoulder) is a common but poorly understood shoulder condition for which sufferers generally note diffuse yet severe shoulder pain, combined with a loss of active range of motion (AROM), or how far you can move you shoulder on your own and passive range of motion (PROM), or how far someone else can move your shoulder. The above authors are suggesting that a tender coracoid process is a cardinal/pathognomonic sign of adhesive capsulitis.
I had to google the meaning of pathognomonic sign, which is “a particular sign whose presence means that a particular disease is present beyond any doubt.”
Well, here’s doubt; which I describe at length in my blog Coracoidopathy the Missing Link in Shoulder Pain. The gist is that there are three tendons attaching to the coracoid process for which Karim 2005 thinks the coracobrachialis (CB) and the short head of the biceps (SHB) are the source of pain. Bhatia 2007 thinks the pectoralis minor (PM) tendon is the source of pain (I disagree but think they’re close), which I discuss specifically in my blog Bench Press Shoulder Pain. Gigante 2016 further confirmed Karim’s results where they diagnosed “coracoid syndrome” (what I call coracoidopathy) also treated with a corticosteroid injection to the coracoid process.
One reason I think Karim and Gigante are correct (more so than Bhatia) is that, besides tenderness with palpation to the coracoid process, I also use an isometric Speed’s test as a strength test to stress the SHB and CB. I find the Speed’s test is often relatively weak and painful. Anatomically the Speed’s test should not stress the PM muscle because the PM does not act to flex the shoulder. Another reason I don’t primarily suspect the PM is that I find warming up with supinated front raises (SFRs) to strengthen the SHB and CB prior to bench pressing usually and immediately lessens bench press (if performed right after) associated shoulder pain. If the PM were the primary source of pain, the SFRs shouldn’t work (lessening pain by warming up the affected tendons) again because the PM does not flex the shoulder.
Where I think Carbone 2010 (above), go wrong is they weren’t able to find either Karim’s or Bhatia’s paper in their lit review. As such, enthesitis, tendinitis, tendinosis or tendinopathy of the tendons attaching to the coracoid process appear not to have been a consideration for differential diagnosis. In my shoulder population only 18% of my coracoidopathy patients also had frozen shoulder, which I treat as two separate conditions. With coracoidopathy combined with frozen shoulder I just combined the treatments (coracoidopathy plus frozen shoulder) thus I strengthen the SHB and CB (often with rotator cuff (RTC) and scapular stabilization exercises as needed), plus shoulder stretching exercises given to treat the lost range of motion secondary to the adhesive capsulitis. A full 82% of my shoulder pain patients who had tenderness over coracoid process did not have the lost range of motion indicative of frozen shoulder. Researchers Karim, Bhatia, and Gigante didn’t report a loss of range of motion in their patients with coracoid process tenderness either.
Consequences of misdiagnosing patients with adhesive capsulitis because of a tender coracoid process would include largely ineffective treatment with perhaps unnecessary stretches and misplaced intracapsular cortisone shots. When such treatment didn’t work it might result in an unnecessary and ineffective surgical treatment, perhaps an acromioplasty.
The other thing that bothers me about using a tender coracoid process as the pathognomonic or cardinal sign of adhesive capsulitis is that it just doesn’t make any obvious sense. Adhesive capsulitis is thought to occur as the joint capsule of the shoulder becomes inflamed, adherent and shrinks resulting in pain and loss of range of motion. However the coracoid process is an extra-capsular structure, which means it lies outside the inflamed joint capsule, such that there is perhaps an association but no clear and causal link between one and the other.
Plus adhesive capsulitis already has what I think is a cardinal sign, which lost shoulder PROM. Such that if I am doing my standard shoulder evaluation, looking at AROM, PROM, resistive tests, followed by palpation. I’m already going to find out if there is adhesive capsulitis. A patient with RTC tendinopathy or tearing might have difficulty, pain, and loss of AROM, combined with painful resistive tests of the RTC musculature, plus likely tenderness over one or more of the RTC tendons. However, PROM should be intract. A person with adhesive capsulitis will have limitations in both AROM and PROM while resistive tests are generally not that irritating. A patient with coracoidopathy will likely have pain and weakness with supinated shoulder flexion (isometric Speed’s test) and will, in my experience certainly be tender with palpation over the coracoid process. I think combinations of the above are common, which can be very confusing if you are not aware that coracoidopathy is a potential diagnosis/confounder.
So I think the “coracoid pain test” is certainly an important test that should be performed with every shoulder evaluation (it only takes 5 seconds) but I don’t think it’s indicative of a diagnosis of adhesive capsulitis. Rather I think it it is frequently comorbid with adhesive capsulitis.
As noted the bulk of what I have to say about the diagnosis and treatment of coracoidopathy is here. In fact here’s a video of one patient (of many) with an obvious positive coracoid pain test and no loss of AROM or PROM, thus obviously not a pathognomonic sign of adhesive capsulitis.
I’m gradually writing more about the coracoidopathy, comparing and contrasting with other diagnoses and treatments here.
As always, if you have any further questions, need for clarifications, or think I’m dead wrong, please don’t hesitate to say.
Chad Reilly, Physical Therapist