Empty can test may be performed with the patient standing or seated.
With the elbow extended, the patient’s arm is held at 90 degrees of abduction, 30 degrees of horizontal flexion, and in internal rotation.
The examiner exerts pressure on the upper arm during the abduction and horizontal flexion motion.
Using electromyography EMG, this test enables testing of the supraspinatus muscle largely in isolation.
It is important to apply pressure gently at first and to increase the pressure only if pain has not been triggered during the course of the test to that point.
The empty can test can be performed similarly with the humerus externally rotated, this called a full can test.
Full Can Test:
This test is done with the patient standing or sitting.
Similar to the empty can test, the elbow is extended and the patient’s arm is held at 90° of abduction, 30° of horizontal flexion, and in external rotation.
Then the examiner applies a pressure on the examined limb.
What does a positive Empty Can Test mean?
When Jobe Test elicits severe pain and the patient is unable to hold his or her arm abducted 90° against gravity, this is called a positive drop arm sign.
The superior portions of the rotator cuff (supraspinatus muscle) are particularly assessed in internal rotation (with the thumb down as when emptying a can), and the anterior portions in external rotation (thumb points upward – full can).
The Empty Can Test may be repeated at only 45° abduction to further differentiate the findings.
Where the impingement component predominates, there will be less pain and more strength where the tendon is still intact.
The Empty Can Test can yield false-positive results where pathology of the long head of the biceps tendon is present.
If the test elicits pain and the patient is unable to abduct the arm 90° and hold it against gravity, this indicates a tear of the tendon of the supraspinatus muscle, or damage to the suprascapular nerve.
Strength in the supraspinatus muscle may not be completely diminished until over two-thirds of the tendon is torn.
Empty Can Test Accuracy
A Cohort Study 1 by Nitin B Jain found that empty can test had a high sensitivity and specificity for supraspinatus tears as following:
Sensitivity: 88 %
Specificity: 62 %
Another study 2 found the empty can test to have a high sensitivity of 86% and a low specificity of 50% in diagnosing supraspinatus tendon tears in a series of 55 patients.
The full can test had higher specificity (74% vs. 68%) and an equal sensitivity of 77% when compared with the empty can test in a series of 136 patients 3.
Starter Test or Zero-Degree Abduction Test is another test for rotator cuff tear especially the Supraspinatus tendon.
The patient stands with his or her arm s hanging relaxed. The examiner grasps the distal third of each forearm. The patient attempts to abduct the arms against the examiner’s resistance.
Abduction of the arm is “started” by the supraspinatus and deltoid muscles. Pain and, especially, weakness in abducting and holding the arm strongly suggest a rotator cuff tear.
Studies performed by anesthetizing the suprascapular and axillary nerves show that the supraspinatus and deltoid muscles are responsible for abduction of the arm.
The supraspinatus muscle, along with the other muscles of the rotator cuff , press the head of the humerus into the socket and abduct the arm for the first 20°, then the deltoid muscle comes into play.
Even if the supraspinatus muscle tendon is completely torn, the shoulder is still capable of good range of motion.
There is a deficit only at the onset of abduction and then again when the arm reaches 90° and above.
EMG tests show no difference in the EMG activity whether the arm is held in full internal rotation (classic Jobe empty can position), with the thumb pointing to the floor, or with the arm in maximum external rotation (full can position).
The strength of the supraspinatus muscle can also be tested with the elbows flexed rather than extended.
For the patient, this position requires less holding power and less stress, and is therefore also less painful.
A partial rupture of the supraspinatus tendon will result in abduction that is both weak and painful. A painless weakness with abduction could indicate a complete rupture of the supraspinatus tendon, although the deltoid cannot be ruled out. The tendon of the supraspinatus can be passively stretched by positioning it in adduction and IR to see if this increases the pain.
Eccentricity of the humeral head in the form of superior displacement of the humeral head in a rotator cuff tear causes relative insufficiency of the outer muscles of the shoulder. Small tears that can be functionally compensated for will cause minor loss of function with the same amount of pain. Larger tears are invariably characterized by weakness and loss of function.
There are four rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis muscles).
supraspinatus muscle originates from Superior scapula and inserts onto Humerus Greater tuberosity. It’s innervated by Suprascapular nerve.
Its action is abducting and externally rotating the arm, providing stability to the shoulder joint.
Nitin B Jain, Jennifer Luz, Laurence D Higgins, Yan Dong, Jon J P Warner, Elizabeth Matzkin, Jeffrey N Katz. The Diagnostic Accuracy of Special Tests for Rotator Cuff Tear: The ROW Cohort Study.Am J Phys Med Rehabil. 2017 Mar. PMID: 27386812.
Leroux JL, Thomas E, Bonnel F, Blotman F. Diagnostic value of clinical tests for shoulder impingement syndrome. Rev Rhum Engl Ed. 1995 Jun;62(6):423-8. PMID: 7552206.
Itoi E, Kido T, Sano A, Urayama M, Sato K. Which is more useful, the “full can test” or the “empty can test,” in detecting the torn supraspinatus tendon? Am J Sports Med. 1999 Jan-Feb;27(1):65-8. doi: 10.1177/03635465990270011901. PMID: 9934421.
Litaker D, Pioro M, El Bilbeisi H, et al. Returning to the bedside: using the history and physical examination to identify rotator cuff tears. J Am Geriatr Soc. 2000;48:1633-1637
Jobe FW, Moynes DR. Delineation of diagnostic criteria and a rehabilitation program for rotator cuff injuries. Am J Sports Med. 1982;10:336–9.
Campbel’s Operative Orthopaedics 13th Book
Clinical Tests for the Musculoskeletal System 3rd Edition.
Dutton’s Orthopaedic Examination, Evaluation, And Intervention 3rd Edition.