Full Can Test

Purpose[edit | edit source]

Supraspinatus muscle.png

The Full Can Test is used to assess the function of Supraspinatus muscle and tendon of the shoulder complex.

Technique[edit | edit source]

The patient can be seated or standing for this test, holding their arm in 90° of elevation in scapular plane (30° anterior to the frontal plane) with full external rotation of the glenohumeral joint. In this position, the patient's thumb should be pointing up. The therapist should stabilize the shoulder while applying a downward force to the arm whilst the patient tries to resist this motion.

There is no firm consensus for the result of this test, some studies have indicated a positive result as denoted by pain, some by weakness, and some by both[1]. However, an RCT suggests that weakness should be considered the gold standard during interpretation of the test results, due to higher diagnostic accuracy and correlation with arthroscopic findings[1].

[2]

Evidence[edit | edit source]

Kelly et al. reported that the full-can test for assessment of supraspinatus function which had similar electromyographic (EMG) activity compared with the Empty Can Test, but that it provoked less pain. Their findings showed no significant difference in supraspinatus muscle activation with variation in humeral rotation. There is slightly less activation of the infraspinatus muscle leading to a better isolation of the muscle. [3] It is also suggested that in this testing position, there is less activity of surrounding muscles such as deltoid and subscapularis.[4]

The Full Can Test had a sensitivity of 70% (95% CI=59% to 82%) and a specificity of 81% (95% CI=74% to 88%)[5].

Clinical Application[edit | edit source]

A combination of diagnostic tests for supraspinatus tendon tears including the empty can, full can, and the zero-degree abduction tests showed the best AUC (0.795) and hence the best diagnostic value. The combination also had the highest correlation with intraoperative findings, according to a recent RCT[1]. The same study suggested that the full can test was unable to determine between partial thickness and full thickness tears of the supraspinatus tendon[1]. The full can test also showed better diagnostic value and higher correlation with intraoperative results for tears at least 1 cm in size[1].

It is however, questionable on the value that the ‘full can’ test provides, due to the fact that the test does not selectively isolate supraspinatus. EMG studies conducted during the ‘full can’ test showed that 13 muscles were activated in 15 normal subjects[6]. A paper concluded that shoulder ‘special tests’ should only be considered as pain-provocation tests[7].

Additional Resources[edit | edit source]

Anatomy of Shoulder - Acromioclavicular joint, Glenohumeral joint, Sternoclavicular joint and Scapulothoracic joint

Rotator cuff muscles

Biomechanics of Shoulder

Scapulohumeral rhythm

Examination of shoulder and Special tests

Common conditions - Frozen Shoulder, Biceps Tendonitis, Rotator Cuff Tears and Shoulder Instability.

References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 Sgroi M, Loitsch T, Reichel H, Kappe T. Diagnostic Value of Clinical Tests for Supraspinatus Tendon Tears. Arthroscopy. 2018;34(8):2326–33.
  2. Physiotutors. Full Can Test ⎟ Shoulder Impingement. Available from: https://www.youtube.com/watch?v=NuBOHdm20cc [last accessed 2/12/2020]
  3. Kelly BT, Kadrmas WR, Speer KP. The manual muscle examination for rotator cuff strength: an electromyographic investigation. The American journal of sports medicine. 1996 Sep;24(5):581-8.
  4. Lee CK, Itoi E, Kim SJ, Lee SC, Suh KT. Comparison of muscle activity in the empty-can and full-can testing positions using 18 F-FDG PET/CT. Journal of orthopaedic surgery and research. 2014 Dec;9(1):1-8.
  5. Jain NB, Luz J, Higgins LD, Dong Y, Warner JJ, Matzkin E, Katz JN. The diagnostic accuracy of special tests for rotator cuff tear: the ROW cohort study. American journal of physical medicine & rehabilitation. 2017 Mar;96(3):176.
  6. Boettcher, Craig E et al. “The 'empty can' and 'full can' tests do not selectively activate supraspinatus.” Journal of science and medicine in sport vol. 12,4 (2009): 435-9. doi:10.1016/j.jsams.2008.09.005
  7. Salamh P, Lewis J. It is time to put special tests for rotator cuff-related shoulder pain out to pasture. The journal of orthopaedic and sports physical therapy. 2020;50(5):222–5.