Full Can Test

Common symptoms of the full can and empty can test are weakness and pain, therefore both tests need to be used to test for rotator cuff injuries. If pain, weakness, or both are present, these tests are thought to be positive. Since pain modifies muscle strength, there is a concern about the reliability of the empty can test.1 This concern arises because of the internal rotation of the humerus results in impingement, therefore potentially decreases the usefulness of the test. With the empty can test, pain decreases the specificity of the overall test- pain can even be present with an intact rotator cuff.5 Additionally, there can be a 20% reduction in strength that cannot be detected by the tests if the patient is stronger than the clinician. In …show more content…
There was no significance difference in the negative and positive predictive values among the listed criteria. 5 An overall comparison of these tests revealed that the specificity and accuracy were greater in full can test when looking for pain. Looking at muscle weakness instead of pain gave the greatest accuracy in both tests. The full can test also showed greater specificity and accuracy than the empty can test, but the differences were not significant.5 A study done by Timmons et al. compared the scapular position, pain, and area of the subacromial space of the EC and FC tests. This study found that there was no significant difference in the subacromial space for the two tests. When comparing scapular motion, it was found that during the FC test the subjects had less upward rotation, greater posterior tilt, less clavicular elevation, and less clavicular protraction when compared to the EC