Muscle of Lower Body

Muscles of the Lower Body

  • Lower Body Muscles Overview

    • Includes major muscle groups: Driceps, Glutes, Hamstrings.

Lab Instructions

  • Materials Required:

    • E-Text and Document

    • Anterior and Posterior Skeleton

    • Building Grids

    • Printed Clay or Playdough

    • Anatomy & Physiology Revealed

    • Get Body Smart Practice Atlas (for Review)

The Process of Learning Muscle Anatomy

  • Practice: Learning the muscles using Get Body Smart.

  • Build: Create a clay model of the muscle using the Skeleton Building Model.

  • Watch: Observe the action of the muscle using A&P Revealed.

  • Dissect: Perform virtual dissection using Anatomy & Physiology Revealed.

  • Learn: Explore detailed information about the muscle anatomy.

Muscles of the Hip and Thigh

Gracilis Muscle

  • Origin: Inferior ramus and body of the pubic bone.

  • Insertion: Medial condyle of tibia.

  • Action: Adducts the thigh and flexes the leg.

Quadriceps Group

  • Consists of four muscles:

    1. Vastus Intermedius

    2. Vastus Medialis

    3. Vastus Lateralis

    4. Rectus Femoris

Vastus Intermedius

  • Origin: Shaft of femur; ¾ of dorsal and dorsolateral surface of femur from near the lateral linea aspera to the crest of anteromedial femur; fascia casing the muscle.

  • Insertion: Mid-tibial tuberosity.

  • Action: Extends the knee.

Vastus Medialis

  • Origin: Shaft of femur; ¼ surface of femoral shaft from the medial intertrochanteric line to near the medial edge of the linea aspera; intermuscular septa.

  • Insertion: Dorsomedial fascia of vastus intermedius; medial patella; medial tibial tuberosity.

  • Action: Extends the knee, displaces the patella medially, and rotates the femur laterally on the tibia.

Rectus Femoris Muscle

  • Origin:

    • Straight Head: Anterior Inferior Iliac Spine

    • Reflected Head: Cranial lip of acetabulum

  • Insertion: Joins tendon of vastus intermedius variably at 1/3 its length above the knee; cranial patella; tibial tuberosity.

  • Action: A two-joint extensor of the knee. Flexes the hip.

Sartorius Muscle

  • Known as the Tailor's Muscle; involved in flexion, abduction, and lateral rotation of the hip.

Muscles of the Shin and Calf

Tibialis Anterior Muscle

  • Origin: Medial surface of tibia.

  • Insertion: Posterior tibials tendon.

  • Action: Dorsiflexion of the foot and inversion of the ankle.

Gastrocnemius Muscle

  • Part of the triceps surae group.

  • Origin: Lateral and medial condyles of the femur.

  • Insertion: Calcaneus (via Achilles tendon).

  • Action: Plantarflexes the foot and flexes the leg.

Soleus Muscle

  • Part of the triceps surae group; lies beneath the gastrocnemius.

  • Origin: Head of the fibula and the medial proximal tibia.

  • Insertion: Calcaneus.

  • Action: Plantarflexes the foot, important muscle for walking.

Gluteal Muscles

Gluteus Maximus Muscle

  • Origin: Sacrum and ilium.

  • Insertion: Proximal femur.

  • Action: Extends the hip during forceful exertion.

Gluteus Medius Muscle

  • Origin: Lateral surface of ilium.

  • Insertion: Greater trochanter of femur.

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

Piriformis Muscle

  • Origin: Anterior surface of lateral sacrum.

  • Insertion: Greater trochanter of femur (along the medial surface).

  • Action: Laterally rotates the thigh at the hip.