I.E.2 Forearm, Carpal Region & Hand: Forearm Flexors & Extensors: Page 1 of 5

Objectives:

5.2.1 Identify the muscles of the flexor and extensor regions of the forearm, their primary actions and sources of innervation.

5.2.2 Demonstrate the specialization of the distal end of the extensor digitorum tendon.

Assigned Readings:

Moore's COA: Pages 148-151, 241-258. See blue boxes on pages 258-262 for clinical correlations. See yellow boxes on pages 262-263 for "The Bottom Line."

Step 1: Start with the posterior cadaveric view of the forearm.

	Why is this considered the anterior part of the forearm?
Remember that this cadaver is not in the antomical position. In the anatomical position, the anterior part of the forearm and the palmar surface of the hand face anterior.

Add the deep muscle layer of the anterior forearm:

	Step 2: Add the pronator quadratus.
	Step 3: Add the pronator teres.

	What does the word "pronate" mean?
It is derived from Latin, and means to bend forward. So that in this case, it means to rotate the forearm so that the palm of the hand is facing posterior. This term can be used with the foot too. Remember, to turn someone into the prone position is to roll them from their back onto their stomach.
	How do these muscles accomplish pronation of the forearm?
When they contract, the radius rotates at the elbow and the distal radius crosses over the ulna. They are assisted by the anconeus muscle which is part of the posterior muscle group.