The empty can test may be a clinical trial wont to test the integrity of the supraspinatus tendon. The Empty Can Test is employed to assess the supraspinatus muscle and supraspinatus tendon. during this test, the patient is tested at 90° elevation within the scapular plane and full internal rotation (empty can). The patient resists downward pressure exerted by the examiner at the patient’s elbow or wrist.
The Empty Can Test (ECT) was originally described by Jobe and Moynes to check the integrity of the supraspinatus tendon. Kelly later proposed the complete Can Test (FCT) as an alternate as if EMG activity within the supraspinatus was similar in both positions the FCT was less provocative. It was, therefore, less likely to end in muscle weakness thanks to pain provocation.
The accuracy of the tests was the best when muscle weakness was interpreted as indicating a torn supraspinatus tendon in both the complete can test (75% accurate) and therefore the empty can test (70% accurate). The tests differ within the rotation of the arm; within the empty can test, the arm is rotated to full internal rotation (thumb-down) and within the full can test, the arm is rotated to 45° external rotation, thumb up.
Test
The patient is tested at 90° elevation within the scapular plane and full internal rotation (empty can) or 45°external rotation (full can). The patient resists downward pressure exerted by the examiner at the patient’s elbow or wrist.
The therapist should stabilize the shoulder while applying a downward force to the arm whilst the patient tries to resist this motion. This test is taken into account positive if the patient experiences pain or weakness with resistance to the shoulder complex.
With thanks to Kathleen Tatlow
Positive
FCT
- Pain
- Muscle weakness Pain/Muscle Weakness/Both
ECT
- Pain
- Muscle weakness Pain/Muscle Weakness/Both
- Pain located to the subacromial region and/or weakness.
Research
In the study, the two tests were performed on 143 shoulders of 136 consecutive patients. The tests were considered positive when there was pain, muscle weakness, or both. Shoulders were then examined by high-resolution MRI with 95% accuracy for full-thickness tears of the supraspinatus tendon. There were 35 shoulders with a full-thickness tear of the supraspinatus tendon. The accuracy of the tests was the greatest when muscle weakness was interpreted as indicating a tom supraspinatus tendon in both the full can test (75% accurate) and the empty can test (70%) accurate).
Itoi suggests that as the empty can position is more likely to be pain-provoking, the full-can test may be more beneficial in the clinical setting.
| Sensitivity | Specificity | Accuracy |
| 66% | 64% | 64% |
| 77% | 74% | 75% |
| 86% | 57% | 64% |
| 63% | 77% | 89% |
| 55% | 68% | 50% |
| 57% | 57% | 59% |
Kelly, Kadrmas & Speer (1996) showed the best position for maximal isolation of the supraspinatus muscle was best achieved with the test position of elevation at 90° of scapular elevation and +45° (external rotation) of humeral rotation (‘full can’). Howver, Boettcher, Ginn & Carruthers (2009) demonstrated in EMG studies that the supraspinatus is not sufficiently isolated in the empty can position of abduction, calling into question the validity of this test for the diagnosis of supraspinatus pathology.
References
