For various shoulder pathologies and movement impairment syndromes, one of the most common contributing factors includes a lack of sufficient scapular upward rotation. This is often due to insufficient activity of the trapezius and serratus anterior muscles. The serratus anterior muscle is capable of providing both a protraction and upward rotation force. It is the upward rotation force that we are wanting to test, however. In my clinical practice thus far, I have seen several different ways of testing the serratus anterior, but it is essential that the upward rotatory force is assessed.
Origin: outer surfaces and superior borders of upper 8-9 ribs
Insertion: costal surface of the medial border of the scapula
Take a look at the video below for how to perform the MMT. How do you test the serratus anterior and what are some ways you like to train the muscle?
Kendall FP, McCreary EK, Provance PG, Rodgers MM & Romani WA. Muscles Testing and Function with Posture and Pain, 5th ed. Baltimore, MD: Lippincott Williams & Watkins. 2005. 332-333. Print.