Lecture 23 - Muscles Of The Gluteal & Hip Regions

Question 1

What is the origin/insertion/innervation/main action of the gluteus Maximus?

Answer 1

• O: Posterior sacrum, coccyx, posterior gluteal line of the ilium
• I: 1/4 to gluteal tuberosity of femur, 3/4 to iliotibial band
• Inn: Inferior Gluteal nerve
• MA: Hip extension (powerful), Lateral rotation of the extended hip

Question 2

What is the origin/insertion/innervation/main action of the gluteus medius?

Answer 2

• O: External blade of ilium (between anterior & posterior gluteal lines
• I: Greater trochanter of femur
• Inn: Superior Gluteal nerve
• MA: Hip abduction

Question 3

What is pelvic stabilization of the gluteus medius?

Answer 3

• Important pelvic stabilizer during walking
• Maintains horizontal pelvic alignment during the single leg stance phase of walking
• Lack of stabilization results in a Trendelenberg Gait

Question 4

What is the origin/insertion/innervation/main action of the gluteus minimus?

Answer 4

• O: External blade of ilium (between inferior & anterior gluteal lines)
• I: Greater trochanter of the femur
• Inn: Superior Gluteal nerve
• MA: Hip abduction

Question 5

What is the origin/insertion/innervation/main action of the tensor fascia latae?

Answer 5

• O: Anterior Superior Iliac Spine
• I: Iliotibial Band
• Inn: Superior Gluteal nerve
• MA: Splinting the knee in an extended position via the “screw home mechanism”, Extension of the knee, Lateral rotation of flexed knee

Question 6

What are the 6 lateral rotators of the hip?

Answer 6

• piriformis
• Obturator Internus
• Obturator Externus
• Superior Gemelli
• Inferior Gemelli
• Quadratus Femoris

Question 7

What is the origin/insertion/innervation/main action of the piriformis?

Answer 7

• O: Anterior sacrum & sacrotuberous ligament, exits through the greater sciatic foramen with the Sciatic Nerve
• I: Greater Trochanter of the femur
• Inn: Nerve to Piriformis
• MA: Lateral rotation of the hip

Question 8

What is the insertion & main actions of the, Obturator Internus, Obturator Externus, Superior Gemelli, Inferior Gemelli, Quadratus Femoris

Answer 8

• Insertion: greater trochanter of the femur
• MA: lateral (external) rotation of the hip

Question 9

What is the Iliotibial band?

Answer 9

• Runs from the iliac crest, sacrum & inguinal ligament proximally, crosses the knee & attaches to the proximal tibia