Lecture Notes: Muscles of the Hip and Thigh

Overview

• Focus on understanding the muscles involved in shaping the hip and thigh.
• Breakdown of hip muscles (anterior and posterior) and thigh muscles (anterior, medial, and posterior compartments).
• Clinical notes on related common injuries.

Muscles of the Hip

Anterior Hip Muscles

• Psoas Major

  • Origin: Vertebrae T12 to L4, L1 to L5.
  • Innervation: Femoral nerve, lumbar plexus.
  • Blood Supply: Iliolumbar artery, medial femoral circumflex artery.
  • Function: Flexor of the thigh at the hip joint.

• Iliacus

  • Origin: Iliac fossa.
  • Innervation: Femoral nerve.
  • Function: Part of the iliopsoas muscle group, major flexor of the thigh.

• Psoas Minor (often absent)

  • Origin: Along psoas major.
  • Innervation: Lumbar plexus.

Gluteal Muscles (Posterior Hip Muscles)

• Superficial Gluteal Muscles

  • Gluteus Maximus

    • Origin: Ilium, sacrum, coccyx.
    • Insertion: Gluteal tuberosity, iliotibial tract.
    • Innervation: Inferior gluteal nerve.
    • Function: Extension, abduction, rotation of the thigh.

  • Gluteus Medius & Gluteus Minimus

    • Origin: Gluteal surface of the ilium.
    • Insertion: Greater trochanter.
    • Innervation: Superior gluteal nerve.

  • Tensor Fasciae Latae

    • Origin: Anterior superior iliac line.
    • Insertion: Iliotibial tract.

• Deep Gluteal Muscles

  • Piriformis: Lateral rotation of the thigh.
  • Obturator Internus: Lateral rotation.
  • Gemellus (Superior & Inferior)
  • Quadratus Femoris: Lateral rotation.
  • Innervation: Sacral plexus.
  • Blood Supply: Superior and inferior gluteal arteries.

Muscles of the Thigh

Anterior Compartment

• Sartorius

  • Longest muscle, flexes thigh and knee.
  • Origin: Anterior superior iliac spine.
  • Insertion: Medial surface of the tibia.

• Quadriceps Femoris Group

  • Rectus Femoris, Vastus Lateralis, Vastus Intermedius, Vastus Medialis.
  • Function: Extensor of the leg at the knee.
  • Innervation: Femoral nerve.

Medial Compartment

• Obturator Externus, Pectineus, Gracilis
  • Function: Adductors of the thigh.
  • Innervation: Obturator nerve, femoral nerve (pectineus), tibial nerve (adductor magnus).

Posterior Compartment (Hamstrings)

• Biceps Femoris, Semitendinosus, Semimembranosus
  • Function: Flexion of the leg at the knee, extension of the thigh at the hip.
  • Innervation: Tibial nerve (except short head of biceps femoris by common fibular nerve).

Clinical Notes

• Pulled Hamstring: Common sports injury, involves pain and swelling at the back of the thigh.
  • Treatment: Rest, ice, compression, elevation (RICE), and physical therapy if necessary.

Summary

• Hip muscles: Anterior and Posterior (Gluteal) division.
• Thigh muscles: Anterior, Medial, and Posterior compartments.
• Clinical relevance of hamstring injuries.