Chapter 4 - Muscles of the Hip

List the Muscles of the Posterior-Lateral Hip

• M. Gluteus maximus

• M. Gluteus medius

• M. Gluteus minimus

Describe M. Gluteus maximus. Origin, Insertion, Action

Origin: posterior portion of iliac crest; posterior superior iliac spine; posterior sacrum

Insertion: 25% to gluteal tuberosity of femur; 75% into iliotibial tract of thigh fascia lata

• Muscle acts directly on femur via gluteal tuberosity (roughened area)

• Muscle acts indirectly on femur via iliotibial tract (attached to linea aspera of femur by lateral intermuscular septum)

Action: extension of thigh at hip joint

• With foot planted and thigh flexed, gluteus maximus pushes body forward (running; climbing)

• Progressive relaxation controls rate of thigh flexion during sitting

Describe M. Gluteus medius. Origin, Insertion, Action

Origin: lateral (external) surface of ilium portion of hipbone

Insertion: greater trochanter of femur

Action: abduction of thigh at hip joint

• Action during walking: with one foot off the ground, these muscles contract on weight-bearing side to maintain horizontal position of the pelvis

—» Prevents drop of unsupported side of pelvis by pulling pelvis toward weight-bearing limb

Describe M. Gluteus minimus. Origin, Insertion, Action

Origin: lateral (external) surface of ilium portion of hipbone (deep to m. gluteus medius)

Insertion: greater trochanter of femur

Action: abduction of thigh at hip joint

• Action during walking: with one foot off the ground, these muscles contract on weight-bearing side to maintain horizontal position of the pelvis

—» Prevents drop of unsupported side of pelvis by pulling pelvis toward weight-bearing limb

Describe M. Tensor fasciae latae. Origin, Insertion, Action

Origin: anterior superior iliac spine of hipbone

Insertion: iliotibial tract of fascia lata

Actions: abducts thigh at hip joint; extends leg at knee joint*

• Attachment of iliotibial tract to tibia is anterior to axis of knee flexion-extension - pull by iliotibial tract thus produces extension of leg at knee joint

• Slight contraction by tensor fasciae latae muscle serves to maintain extended knee during standing*

List the deep lateral rotator muscles

• M. Piriformis

• M. Obturator internus

• Mm. Superior & Inferior gemelli

• M. Quadratus femoris

• M. Obturator externus

Describe M. Piriformis. Origin, Insertion, Action

Origin: anterior (internal) surface of sacrum

• Exits pelvis via greater sciatic foramen

Insertion: greater trochanter of femur

Action: lateral rotation of thigh at hip joint

Piriformis muscle is a key landmark of the deep posterior hip region

• Superior gluteal nerve & artery emerge at superior margin of piriformis

• Inferior gluteal nerve & artery and sciatic nerve emerge at inferior margin of piriformis muscle

Describe M. Obturator internus. Origin, Insertion, Action

Origin: internal surface of obturator foramen

• Exits pelvis via lesser sciatic foramen

Insertion: greater trochanter of femur

Action: lateral rotation of thigh at hip joint

Describe Mm. Superior & Inferior gemelli. Origin, Insertion, Action

Origin: external surface of hipbone (ischium), just above or below lesser sciatic notch

Insertion: greater trochanter of femur

• Gemelli muscle tendons fuse with tendon of obturator internus muscle just prior to insertion

Action: lateral rotation of thigh at hip joint

Describe M. Quadratus femoris. Origin, Insertion, Action

Origin: ischial tuberosity of hipbone

Insertion: greater trochanter of femur

Action: lateral rotation of thigh at hip joint

Describe M. Obturator externus. Origin, Insertion, Action

Origin - external surface of obturator foramen

• Muscle origin is in deep, medial thigh - it then runs medial and posterior to the femur

Insertion - greater trochanter of femur (on posterior side of femur)

Action - lateral rotation of thigh at hip joint

List the muscles of the anterior hip

• M. Iliopsoas

• M. Psoas major

• M. Iliacus

Describe M. Iliopsoas

formed by fusion of psoas major muscle and iliacus muscle

Describe M. Psoas major. Origin

Origin: lumbar vertebrae

Describe M. Iliacus. Origin, Insertion, Action

Origin: iliac fossa of hipbone

Both muscles descend along pelvic brim (psoas major is medial to iliacus), then pass under the inguinal ligament to enter the anterior thigh.

• Iliacus and psoas major muscles fuse as they pass under inguinal ligament - name changes to become single M. iliopsoas

Insertion: lesser trochanter of femur (only muscle that attaches to lesser femur)

Action: flexion of thigh at hip joint