Muscles of the thigh

Muscles of the Thigh

Overview of the Pelvic Girdle

• Pelvic Girdle: A stable structure for lower limbs, connecting to the sacrum, less mobile compared to the pectoral girdle.

  • Role in positioning and stabilizing the body.

  • Limited movement is vital for maintaining balance and energy efficiency during activities like walking and standing.

Gluteal Region Muscles That Move the Femur

• The primary muscles controlling the femur are in the gluteal region.

  • Gluteus Maximus: Largest gluteal muscle, essential for hip extension.

  • Gluteus Medius: Lies deep to the gluteus maximus, assists in hip abduction.

  • Gluteus Minimus: The smallest of the three, also aids in hip abduction.

• Other significant muscles in this area include:

  • Tensor Fascia Latae: Synergist with gluteus medius, stabilizes the knee and assists with thigh flexion and abduction.

  • Deep muscles contributing to femur rotation:

    • Piriformis

    • Obturator Internus and Externus

    • Superior and Inferior Gemelli

    • Quadratus Femoris

• Adductor Muscles on the medial thigh:

  • Adductor Longus: Flexes the thigh.

  • Adductor Brevis: Works with the longus for thigh movement.

  • Adductor Magnus: Extends the thigh.

  • Pectineus: Aids in flexion and adduction of the femur.

Functions of Thigh Muscles

• Despite limited motion, thigh muscles provide strength and stability, essential for:

  • Maintaining posture.

  • Facilitating a variety of movements in biomechanics.

  • Essential for walking, running, and other physical activities.

Thigh Muscles Divided by Compartment

Anterior Compartment

• Responsible for:

  • Thigh flexion and leg extension.

• Quadriceps Femoris Group:

  • Rectus Femoris: Flexes the thigh and extends the leg.

  • Vastus Lateralis: Extends the leg.

  • Vastus Medialis: Also extends the leg.

  • Vastus Intermedius: Contributes to extension.

• Sartorius Muscle:

  • Unique for its ability to flex, abduct, and laterally rotate the leg.

Medial Compartment

• Contains muscles for:

  • Adducting the Femur:

    • Gracilis: Flexes the leg at the knee.

    • Adductor Longus: Thigh flexion and adduction.

    • Adductor Brevis: Thigh adduction.

    • Adductor Magnus: Wide-ranging functions including flexion and extension.

    • Pectineus: Aids in flexion and adduction as well.

Posterior Compartment

• Contains the Hamstring Group:

  • Biceps Femoris: Flexes the knee, extends the thigh.

  • Semitendinosus: Similar functions as the biceps.

  • Semimembranosus: Also flexes the leg and extends the thigh.

  • These muscles contribute to movements such as kneeling and cycling.

Summary of Movements

• Anterior muscles primarily extend and stabilize the leg, medial muscles assist in adduction, while posterior muscles allow for flexion and stabilization. Each compartment showcases specific muscle groups dedicated to a variety of motions essential for everyday activities.

Terms to Know

• Piriformis: A muscle that aids in outward rotation of the thigh and stabilization.

• Sartorius: A versatile muscle that facilitates flexion, abduction, and lateral rotation.