Overview of Lower Limbs and Pelvic Girdle

Oct 13, 2024

Lecture Notes on Lower Limbs and Pelvic Girdle

Pelvic Girdle (Hip Girdle)

  • Composition: Two hip bones, articulating posteriorly with the sacrum.
  • Hip Bones: Each consists of three fused bones:
    • Ilium: Upper part, forms the hip edge.
    • Ischium: Lower part, akin to the tailbone.
    • Pubis: Front part, forms the pubic symphysis.
  • Articulations:
    • Anteriorly at the pubic symphysis (cartilaginous joint).
    • Posteriorly with the sacrum.
  • Anatomical Features:
    • Ilium: Flat, fan-shaped with iliac crest.
    • Acetabulum: Socket for hip joint, formed by all three bones.
    • Obturator Foramen: Passage for obturator nerves and vessels.

Pelvic Brim

  • Divisions:
    • Superior (False/Greater Pelvis): Above the pelvic brim; part of the abdominal cavity.
    • Inferior (True/Lesser Pelvis): Below the pelvic brim; defines the pelvic cavity.
  • Differences in Sex:
    • Male pelvis: Larger, heavier bones, pubic arch < 90 degrees.
    • Female pelvis: Wider, shallower pelvic brim; pubic arch > 90 degrees (adaptation for childbirth).

Lower Limb Structure

  • Femur (Thigh Bone): Longest, strongest bone; articulates with acetabulum and tibia.

    • Head and Neck: Head fits in the acetabulum.
    • Greater and Lesser Trochanters: Muscle and ligament attachment points.
    • Gluteal Tuberosity: Attachment for gluteal muscles.
    • Medial and Lateral Epicondyles: Ligament attachment at the knee.

  • Patella (Kneecap): Sesamoid bone in the quadriceps tendon.

    • Articulates posteriorly with the femur.

  • Tibia and Fibula (Lower Leg):

    • Tibia: Medial, larger bone articulating with femur and talus.
    • Fibula: Lateral, smaller bone, articulating with tibia and talus.
    • Interosseous Membrane: Connects tibia and fibula.
    • Tibial Tuberosity: Patellar ligament attachment.
    • Medial and Lateral Malleolus: Part of the ankle structure.

Ankle and Foot

  • Tarsal Bones: Seven bones forming the ankle.

    • Talus: Articulates with tibia.
    • Calcaneus: Heel bone.
    • Other Tarsals: Navicular, three cuneiforms (medial, intermediate, lateral), and cuboid.

  • Metatarsals and Phalanges:

    • Metatarsals: Five bones, numbered 1-5 starting from the big toe.
    • Phalanges: Two in the big toe (hallux), three in other toes (distal, intermediate, proximal).

  • Foot Arches:

    • Longitudinal Arch: Medial and lateral portions; supports weight and provides leverage.
    • Transverse Arch: Runs laterally to medially; aids in weight distribution.

These notes cover the key bone structures and anatomical landmarks of the lower limbs and pelvic girdle, providing a comprehensive overview of the skeletal components involved in support and movement.