Shoulder Orthopaedic Test: Infraspinatus Test

The infraspinatus muscle is one of the four muscles that make up the rotator cuff in the shoulder. It is responsible for externally rotating the shoulder and stabilizing the humeral head in the glenoid fossa.

The infraspinatus test is a physical examination technique used to assess the function of the infraspinatus muscle.

Procedure:

1. Ask the patient to sit or stand with their arms by their sides.
2. Instruct the patient to abduct their arm to 90 degrees and flex their elbow to 90 degrees, with their palm facing down.
3. Stand behind the patient and grasp their forearm just above the wrist with one hand, while placing your other hand on their opposite shoulder to stabilize it.
4. Apply resistance to the patient's forearm as they attempt to externally rotate their arm against the resistance.
5. Observe the patient's ability to maintain the arm in the starting position and resist the external rotation force applied by you.
6. Repeat the test on the opposite arm.
7.  

A normal result of the infraspinatus test would be the patient's ability to maintain their arm in the starting position and resist the external rotation force applied by the examiner without experiencing pain or discomfort. This would suggest that the infraspinatus muscle is intact and functioning properly.

References:

1. Jobe, F.W., Moynes, D.R., & Tibone, J.E. (1987). Infraspinatus muscle atrophy in massive rotator cuff tears. American Journal of Sports Medicine, 15(6), 554-557. doi: 10.1177/036354658701500614
2. Magee, D.J. (2014). Orthopedic Physical Assessment (6th ed.). St. Louis, MO: Elsevier Health Sciences.
3. Neumann, D.A. (2010). Kinesiology of the Musculoskeletal System: Foundations for Physical Rehabilitation (2nd ed.). St. Louis, MO: Mosby Elsevier.
4. O'Connor, F.G., Wilder, R.P., & Sallis, J.F. (2005). Handbook of Sports Medicine: A Symptom-Oriented Approach (3rd ed.). Philadelphia, PA: Lippincott Williams & Wilkins.
5. Physical Therapy Toolkit. (n.d.). Infraspinatus muscle test. Retrieved from https://www.physicaltherapytoolkit.com/shoulder/infraspinatus-muscle-test/