I.B.2 Gluteal Region & Thigh: Gluteal Region, Posterior & Medial Thigh: Page 1 of 3

Objectives:

2.2.1 Identify the muscles and nerves (sensory and motor) of the gluteal and posterior thigh regions, and describe the actions and nerve supply for each muscle.

2.2.2 Predict the motor and sensory defects in the gluteal and thigh regions that would result from damage to the nerves.

2.2.3 Trace the flow of blood from the common iliac artery to the gluteal regionand hip joint.

2.2.4 Demonstrate the known collateral connections in the gluteal region and hip joint. Trace the venous return from these areas to the inferior vena cava.

2.2.5 Identify the muscles and nerves (sensory and motor) of the medial thigh region, and describe the actions and nerve supply for each muscle.

2.2.6 Predict the motor and sensory deficits in the medial thigh region that would result from damage to the nerves.

Assigned Readings:

Moore's COA: Pages 691-698, 703-710. See blue boxes on pages 699-700 for clinical correlations. See the yellow box on page 700 for "The Bottom Line."

Step 1: Begin with the pelvic region. Note that this is a posterior view.

The following muscles form the gluteal region:

	Step 2: The obturator internus.
	Step 3: The inferior gemellus.
	Step 4: Add the superior gemellus.
	Step 5: Add the piriformis.

	The piriformis muscle is often injured in people who run. Why is this muscle so susceptable to injury?
It inserts into the medial side of the greater trochanter of the femur and laterally rotates the extended hip joint and abducts the flexed hip. This is very necessary for the running gait.

Step 6: Add the quadratus femoris.

All of the above muscles laterally rotate the hip and assist in the abduction of the femur during walking and running.

	Step 7: Add the superior gluteal nerve.
	Step 8: Add the inferior gluteal nerve.
	Step 9: Add the sciatic nerve.

	One of the symptoms of piriformis injury is a burning sensation. Why?
Swelling of the piriformis muscle compresses the sciatic nerve, leading to this sensation.