Hamstring Muscles Anatomy and Function

Hamstring Muscles

• Biceps femoris:
  • Origin: Upper part of medial surface of tibia
  • Insertion: Fibula
  • Nerve supply: Sciatic nerve
  • Action: Flexion and lateral rotation of knee
• Semitendinosus:
  • Origin: Upper lateral part of ischeal tuberosity
  • Insertion: Groove on back of medial condyle of tibia and capsule of knee joint
  • Nerve supply: Sciatic nerve
  • Action: Flexion and medial rotation of knee
• Semimembranosus:
  • Origin: Upper lateral part of ischeal tuberosity
  • Insertion: Groove on back of medial condyle of tibia and capsule of knee joint
  • Nerve supply: Sciatic nerve
  • Action: Flexion and medial rotation of knee

Anterior Compartment Muscles

• Tibialis Anterior:
  • Origin: Upper 1⁄2of lateral surface of tibia
  • Insertion: Base of 1st metatarsal bone
  • Nerve supply: Deep peroneal nerve
  • Action: Dorsiflexion and foot inversion
• Extensor Hallucis Longus:
  • Origin: Middle 2⁄4 of anterior surface of fibula
  • Insertion: Base of distal phalanx of big toe
  • Nerve supply: Deep peroneal nerve
  • Action: Extension of M/P and I/P joints of big toe + dorsiflexion
• Extensor Digitorum Longus:
  • Origin: Upper 3⁄4 of anterior surface of fibula
  • Insertion: Base of middle and distal phalanges of lateral 4 toes
  • Nerve supply: Deep peroneal nerve
  • Action: Extension of M/P and I/P joints of lateral 4 toes + dorsiflexion

Lateral Compartment Muscles

• Peroneus Tertius:
  • Origin: Lower 1⁄4of anterior surface of fibula
  • Insertion: Base of 5th metatarsal bone
  • Nerve supply: Deep peroneal nerve
  • Action: Dorsiflexion and foot eversion

Peroneal Muscles

• Peroneus Longus:
  • Origin: Upper 2⁄3 of lateral surface of fibula
  • Insertion: Lateral side of base of 1st metatarsal bone
  • Nerve supply: Musculocutaneous nerve (superficial peroneal nerve)
  • Action: Eversion and plantar flexion of foot
• Peroneus Brevis:
  • Origin: Lower 2⁄3 of lateral surface of fibula
  • Insertion: Tuberosity at base of 5th metatarsal bone
  • Nerve supply: Musculocutaneous nerve (superficial peroneal nerve)
  • Action: Eversion and plantar flexion of foot

Posterior Compartment Muscles

• Gastrocnemius:
  • Origin: Lateral head: lateral condyle of the femur, Medial head: popliteal surface of the femur above medial condyle
  • Insertion: Tendocalcaneous (Achilles) into middle 1/3 of posterior surface of calcaneous
  • Nerve supply: Medial popliteal (tibial) nerve
  • Action: Plantar flexion of foot
• Soleus:
  • Origin: Horse-shoe shaped origin from upper 1/3 of posterior surface of fibula, tendinous arch between tibia and fibula, and soleal line of tibia
  • Insertion: Tendocalcaneous (Achilles) into middle 1/3 of posterior surface of calcaneous
  • Nerve supply: Medial popliteal (tibial) nerve
  • Action: Plantar flexion of foot
• Plantaris:
  • Origin: Popliteal surface of femur above lateral condyle
  • Insertion: Posterior surface of calcaneous medial to tendocalcaneous
  • Nerve supply: Medial popliteal (tibial) nerve
  • Action: Weak plantar flexor of foot (may be absent)
• Popliteus:
  • Origin: Popliteal groove of lateral condyle of femur
  • Insertion: Triangular area of post.of tibia above soleal line
  • Nerve supply: Medial popliteal (tibial) nerve
  • Action: Unlocking the knee by initial medial rotation of tibia below the femur at the beginning of flexion

Deep Posterior Compartment Muscles

• Flexor Digitorum Longus:
  • Origin: Middle 1/3 of posterior surface of tibia below soleal line medial to vertical ridge
  • Insertion: Tendon divides to 4 slips to inserted into terminal phalanges of lateral 4 toes
  • Nerve supply: Posterior tibial nerve
  • Action: Flexion of M/P and I/P joints of lateral 4 toes
• Flexor Hallucis Longus:
  • Origin: Lower 3⁄4 of posterior surface of fibula lateral to medial crest
  • Insertion: Base of terminal phalanx of big toe
  • Nerve supply: Posterior tibial nerve
  • Action: Flexion for all joints of big toe
• Tibialis Posterior:
  • Origin: -Back of tibia lateral to vertical ridge, -Back of fibula infront of medial crest, -Posterior surface of interosseous membrane
  • Insertion: Medial part into navicular tuberosity and medial cuniform bone, Lateral part into all of tarsal bones except talus and base of 2,3,4 metatarsals
  • Nerve supply: Posterior tibial nerve
  • Action: Not mentioned