As we dive further into bettering our practice models in Physical Therapy, I thought we should touch on what we know about the shoulder.
The shoulder is a rather complex series of joins which function to position the hand. Unfortunately, approximately 6 million shoulder injuries are reported per year in the US which result in surgery and/or rehabilitation.
Two of the most common clinical conditions that we see are subacromial impingement and rotator cuff tears (RTC). Alot of special tests have been developed to assess for these shoulder injuries but cluster testing (similar to the SI joint) appears to significantly improve our diagnostic accuracy.
A 2005 article in the Journal of Bone and Joint Surgery found that a combination of three special tests lead to a positive likelihood ratio of 10.56 for any degree of subacromial impingement. These include: positive Hawkins Kennedy test, infraspinatus strength test and painful arc of motion.
The authors further found that a combination of a positive drop arm test, infraspinatus strength test and painful arc of motion have a positive likelihood ratio of 15.57 for having a full thickness RTC tear.
Description of the tests as performed in the literature:
Obviously, as you can see the tests alone tell us little. But when used in conjunction with others, the clusters have good diagnostic accuracy.
Hawkins Kennedy: Passively flex the patient’s arm to 90 degrees within the plane of the scapula, stabilize the elbow which is bent to 90 degrees and internally rotate the shoulder. Tests for subacromial impingement. Sensitivity: 71.5%, Specificity: 66%
Painful Arc: The patient elevates their arm in the scapular plane (or full abduction) actively and complains of pain between 60 and 120 degrees. Tests for RTC pathology. Sensitivity: 73.5%, Specificity: 81%
Infraspinatus Muscle Strength Test: The patient’s elbow is flexed to 90 degrees and the arm is adducted to neutral. Manual pressure is applied into internal rotation and the patient resists into external rotation. A positive test is giving way. Tests for RTC pathology. Sensitivity: 41.6%, Specificity: 90.1%
Drop arm test: The patient is asked to elevate (or examiner passively elevates) arm fully and then is asked to hold and then slowly lower that arm. A positive test is if the arm drops suddenly or if the patient has severe pain holding it. Tests for RTC tear. Sensitivity: 26.9%, Specificity: 88.4%
Other tests of the shoulder (that we may not really need…)
I don’t want to say to completely drop or throw out these tests, but why waste time when we have clusters that have good + likelihood ratios to make same diagnosis?
Neer Test: The clinician stabilizes the patients scapula and passively elevated the patients arm in the scapular plane. A positive test is pain the subacromial space. Tests for subacromial impingement. Sensitivity: 75-89% Specificity: 30-47%.
Full Can Test: The patient holds their arm at 90 degrees of elevation in the scapular plane with 45 degrees of external rotation. The practitioner then applies resistance and attempts to push the arm down. A positive test can be described as either provoking pain or abnormal weakness. Tests for RTC tear. Sensitivity: 66% (pain) 77% (weakness), Specificity: 64% (pain) 74% (weakness).
Jobe’s (Empty Can) Test: The patient holds their arm at 90 degrees of elevation in the scapular plane with full internal rotation (as if pouring out a can of beer). The practitioner than applies resistance and attempts to push the arm down. A positive test can be described as either provoking pain or abnormal weakness. Tests for RTC tear. Sensitivity: 63% (pain) 77-95% (weakness), Specificity: 55% (pain) 65-68% (weakness)
Pendergast, J., Kliethermes, S. A., Freburger, J. K. and Duffy, P. A. (2011), A Comparison of Health Care Use for Physician-Referred and Self-Referred Episodes of Outpatient Physical Therapy. Health Services Research. doi: 10.1111/j.1475-6773.2011.01324.x
Park HB, Yokoto A, Gill HS, Rassi GE, McFarland EG. Diagnostic Accuracy of Clinical Tests for the Different Degrees of Subacromial Impingement Syndrome. Journal of Bone and Joint Surgery. 2005: 87; 1446-1455.
Beaudreuil J, Nizard R, Thomas T, et al. Contribution of clinical tests to the diagnosis of rotator cuff disease. Joint Bone Spine. 2009: 76; 15-19.