How Valid Are Shoulder Tests?

By Warren Hammer, MS, DC, DABCO

It appears that the validity of almost all of the shoulder tests we perform on a daily basis are in question. This is rather frustrating and brings up questions regarding our treatment locations.

Our soft-tissue treatments and joint manipulations decrease patient pain and often resolve their problems, but if the functional tests we use to determine the sites of pain are controversial, then how do we know we are actually on the source of the pain? If we are not on the source of the pain, how valid is our treatment method? Maybe we don't have to be on the source of the pain. Maybe there is a hands-on mechanism at work that has nothing to do with our theories. Clearly, more studies are needed regarding the effects of soft-tissue treatment and the validity of functional testing.

Lewis states that most orthopedic tests for the shoulder cannot truly isolate a particular structure, since when we use tests that compress or stretch an area, adjacent structures also have to be compressed, stretched or contracted.¹ He feels that these tests are basically symptom or pain tests, especially since although they usually demonstrate a high sensitivity (proportion of actual positives correctly identified), they have a low specificity (proportion of negatives correctly identified). In other words, we are unable to determine the patients who don't have the problem, so that prevents us from determining who really has the problem.

The subacromial bursa is highly innervated and is the largest structure in the subacromial space. Most cuff tests have the effect of stressing this sensitive structure. "The areas of insertion of the individual tendons are large because they each splay and then interdigitate with each other. Therefore, tension in any one musculotendinous unit is distributed, directly or indirectly, over a wide area."² Another problem with interpreting functional tests for the cuff is that the coracohumeral and glenohumeral ligaments act as check-reins that become taut in specific positions and could resist stresses that would otherwise fall exclusively on the tendons of the cuff. "The coracohumeral ligament [appears] to reinforce the supraspinatus tendon, to which it is parallel and firmly adherent."²

Recently, Beaudreuil, et al., and Hegedus, et al., conducted a systematic literature review and selected the studies that reported the best diagnostic accuracy for shoulder clinical tests.^3,4Unfortunately, many tests for degenerative rotator-cuff disease have not been evaluated and some of the ones that were evaluated tested small numbers. They concluded that the diagnostic performance of clinical tests for rotator-cuff tendon disease was fragmentary, but that there were objective data to support the usefulness of some of the tests.

The following tests showed low sensitivity and low specificity: the Neer test at 79 percent and 53 percent, and the Hawkins-Kennedy test at 79 percent and 59 percent. For superior labral (SLAP) tears, the Speed test was 32 percent and 61 percent for sensitivity and specificity, respectively. It was concluded that the Speed test had no diagnostic utility for a SLAP lesion.⁴

With regard to rotator-cuff integrity, only the external-rotation lag sign (ERLS) and drop-arm test demonstrated value as specific tests for a tear of any rotator cuff muscle, but the ERLS was more specific for the infraspinatus. The bear-hug and belly-press tests "appear to be valuable as specific tests for ruling in a subscapularis muscle tendon tear when positive," and the internal rotation lag test for the infraspinatus and the lift-off test for the subscapularis were acceptable.^3,4 Weakness of unresisted active external rotation appeared valid for the infraspinatus.

The Hornblower test showed evidence for a tear or dysfunction of the teres minor or infraspinatus. As this particular test is not commonly used, here is how it is performed: With the patient sitting or standing, the shoulder is externally rotated at 90 degrees of abduction. Examiner supports the arm in the scapular plane. The elbow is flexed to 90 degrees and the patient is asked to rotate the arm externally against the resistance. Positive sign is the inability to maintain the externally rotated position and the arm dropping back to neutral position.

Relatively acceptable tests for instability were the apprehension, relocation and anterior-release tests, especially when apprehension, rather than pain, was used as the definition for a positive test.⁴ If pain is the only response, it is also very possible that we are aggravating the cuff. Research regarding the acromioclavicular (AC) joint stated that the active compression test (horizontal adduction across the chest) "may be diagnostic of AC joint pathology." The biceps load II appeared to be useful in diagnosing a SLAP lesion.

The final answers regarding our cuff tests are still not in. Personally, I will not give up on them. What I realize is that they may not be as specific as I thought, but palpating for localized tenderness that correlates with the positive test adds a dimension that has not been tested. This will be the way I will be interpreting many shoulder tests until a definitive conclusion regarding their value is made.

References

1. Lewis JS. Rotator cuff tendinopathy/subacromial impingement syndrome: Is it time for a new method of assessment? Br J Sports Med, 2009;43:259-64.
2. Clark JM, Harryman DT II. Tendons, ligaments, and capsule of the rotator cuff. Gross and microscopic anatomy. J Bone Joint Surg Am, 1992;74:713-25.
3. Beaudreuil J, Nizard R, Thomas T, et al. Contribution of clinical tests to the diagnosis of rotator cuff disease: a systematic literature review. Joint Bone Spine, 2009;(76):15-9.
4. Hegedus EJ, Goode A, Campbell S, et al. Physical examination tests of the shoulder: a systematic review with meta-analysis of individual tests. Br J Sports Med, 2008;42:80-92.