Muscles of the Gluteal Region

Learning Outcomes

  • Identify and describe:

    • Origin, insertion, action, and innervation of key muscles in the gluteal region:

    • Piriformis: Central role in the gluteal area.

    • Gluteal muscles:

      • Gluteus Maximus

      • Gluteus Medius

      • Gluteus Minimus

    • Short lateral rotators of the hip:

      • Gemellus Superior

      • Gemellus Inferior

      • Obturator Internus

      • Quadratus Femoris

      • Obturator Externus

  • Annotate diagrams for any of the mentioned muscles.

  • Develop ethical conduct regarding the material used.

Anatomy of the Lower Limb

  • The lower limb is anatomically divided into:

    • Gluteal region: Posterolateral area between iliac crest and the gluteal fold (defines lower buttock).

    • Thigh: Region between the inguinal ligament and the knee joint.

    • Leg: Area between the knee and ankle joints.

    • Foot: Located distal to the ankle joint.

Gluteal Region Overview

  • Definition: The term "gluteal" refers to the buttocks.

  • Boundaries

    • Superior: Iliac crest

    • Medial: Intergluteal cleft

    • Inferior: Gluteal fold (skin fold)

  • Function: Muscles in this region facilitate movement of the thigh at the hip joint.

Muscles of the Gluteal Region

Two Groups:

  • Superficial Group (includes large muscles):

  • Gluteus Maximus

  • Gluteus Medius

  • Gluteus Minimus

  • Tensor Fasciae Latae

  • Deep Group (includes smaller muscles):

  • Piriformis

  • Gemellus Superior

  • Obturator Internus

  • Gemellus Inferior

  • Quadratus Femoris

Superficial Group: Details

  • Gluteus Maximus:

    • Origin: Iliac crest, posterior gluteal line, lateral surface of ilium, sacrum, coccyx, thoracolumbar fascia.

    • Insertion: Gluteal tuberosity of femur, iliotibial tract.

    • Action: Extension and lateral rotation of thigh at the hip.

    • Innervation: Inferior gluteal nerve.

  • Gluteus Medius:

    • Origin: Anterior iliac crest, lateral surface of ilium between posterior and anterior gluteal lines.

    • Insertion: Greater trochanter of femur.

    • Action: Abduction and medial rotation of thigh at the hip.

    • Innervation: Superior gluteal nerve.

  • Gluteus Minimus:

    • Origin: Lateral surface of ilium between inferior and anterior gluteal lines.

    • Insertion: Greater trochanter of femur.

    • Action: Abduction and medial rotation of thigh at the hip.

    • Innervation: Superior gluteal nerve.

  • Tensor Fasciae Latae:

    • Origin: Iliac crest, lateral surface of anterior superior iliac spine.

    • Insertion: Iliotibial tract.

    • Action: Abducts and medially rotates thigh at hip, extends knee, stabilizes knee in extension.

    • Innervation: Superior gluteal nerve.

Deep Group: Lateral Rotators

  • Piriformis:

    • Origin: Anterolateral surface of sacrum.

    • Insertion: Greater trochanter of femur.

    • Action: Abducts & laterally rotates femur.

    • Innervation: Branches from sacral nerves (S1, S2).

  • Gemellus Superior:

    • Origin: Ischial spine.

    • Insertion: Greater trochanter of femur.

    • Action: Lateral rotation of femur.

    • Innervation: Nerve to obturator internus.

  • Gemellus Inferior:

    • Origin: Ischial tuberosity.

    • Insertion: Greater trochanter of femur.

    • Action: Lateral rotation of femur.

    • Innervation: Nerve to quadratus femoris.

  • Obturator Internus:

    • Origin: Posterior surface of obturator membrane.

    • Insertion: Greater trochanter of femur.

    • Action: Lateral rotation of femur.

    • Innervation: Nerve to obturator internus.

  • Quadratus Femoris:

    • Origin: Ischial tuberosity.

    • Insertion: Intertrochanteric crest of femur.

    • Action: Lateral rotation of femur.

    • Innervation: Nerve to quadratus femoris.

Clinical Applications

  • Intramuscular Injections:

    • Commonly administered in the gluteal region, specifically in the gluteus medius, avoiding gluteus maximus to prevent nerve injury.

    • Allows for gradual absorption of a drug.

  • Function in Movement:

    • Gluteus medius and minimus maintain upright trunk during walking/running by stabilizing the pelvis when opposite foot is raised.

    • Trendelenburg Sign: Indicates weakness/paralysis of these muscles when the pelvis drops on the unsupported side.

  • Iliotibial Band Syndrome (ITBS):

    • A common knee injury due to inflammation of the iliotibial tract.

    • Symptoms include sharp/burning pain in the lateral knee, often affecting endurance athletes.

    • Caused by excessive friction during repetitive knee flexion/extension activities.

References

  • Martini, Nath & Bartholow. Fundamentals of Anatomy and Physiology, 9th-11th Edition.

  • Marieb & Hoehn. Human Anatomy and Physiology, 8th Edition.

  • Sealey, Stephens & Tate. Anatomy and Physiology, 6th Edition.

  • Moore et al. Clinically Oriented Anatomy, 7th Edition.