Lower limb Nerves | Anatomy2Medicine
nerve supply of lower limb

Lower limb Nerves

    • Cutaneous nerves of the lower limb
    • Lateral Femoral Cutaneous Nerve
      • Arises from the lumbar plexus (L2–L3),
      • Innervates the skin on the anterior and lateral aspects of the thigh as far as the knee.
    • Posterior Femoral Cutaneous Nerve
      • Arises from the sacral plexus (S1–S3),
      • passes through the greater sciatic foramen
      • Innervates the skin of the buttock, thigh, and calf.
    • Saphenous Nerve
      • Arises from the femoral nerve in the femoral triangle
      • Pierces the fascial covering of the adductor canal

 

  • Innervates the skin on the medial side of the leg and foot.
  • Is vulnerable to injury (proximal portion) during surgery to repair varicose veins.

 

    • Lateral Sural Cutaneous Nerve
      • Innervates the skin on the posterolateral side of the leg.
    • Medial Sural Cutaneous Nerve
      • Innervates the skin on the back of the leg and the lateral side of the ankle, heel, and foot.
    • Sural Nerve

 

  • Is formed by the union of the medial sural and lateral sural
  • Innervates the skin on the back of the leg and the lateral side of the ankle, heel, and foot.

 

    • Superficial Peroneal Nerve

 

  • innervate the skin on the lateral side of the lower leg and the dorsum of the foot.

 

    • Deep Peroneal Nerve
      • Supplies anterior muscles of the leg and foot
      • Supplies skin of the contiguous sides of the first and second toes.
    • Branches of the lumbar and sacral plexuses
    • Obturator Nerve (L2–L4)
      • enters the thigh through the obturator foramen
      • Anterior Branchinnervates the adductor longus, adductor brevis, gracilis, and pectineus muscles..
    • Femoral Nerve (L2–L4)
    • Superior Gluteal Nerve (L4–S1)
      • Arises from the sacral plexus
      • enters the buttock through the greater sciatic foramen
      • Innervates the gluteus medius and minimus, the tensor fasciae latae, and the hip joint.
    • Inferior Gluteal Nerve (L5–S2)
      • Arises from the sacral plexus
      • enters the buttock through the greater sciatic foramen
      • Innervates the overlying gluteus maximus.
    • Posterior Femoral Cutaneous Nerve (S1–S3)
    • Sciatic Nerve (L4–S3)
      • Arises from the sacral plexus
      • largest nerve in the body.
      • Divides into
        • tibial nerve
        • common peroneal nerve
      • Enters the buttock through the greater sciatic foramen

 

  • Innervates the hamstring muscles by its tibial division, except for the short head of the biceps femoris, which is innervated by its common peroneal division.

 

    • Common Peroneal (Fibular) Nerve (L4–S2)
      • divides into the deep peroneal and superficial peroneal nerves.
      • Is vulnerable to injury as it winds around the neck of the fibula, where it also can be palpated.
      • Gives rise to the
        • lateral sural cutaneous nerve
        • recurrent articular branch to the knee joint.

 

  • Superficial Peroneal (Fibular) Nerve

 

      • Innervates the peroneus longus and brevis muscles

 

  • innervates the skin on the lateral side of the lower leg and the dorsum of the foot.
  • Deep Peroneal (Fibular) Nerve

 

      • Innervates the anterior muscles of the leg
      • divides into

 

  • lateral branch
  • supplies the extensor hallucis brevis and extensor digitorum brevis
  • medial branch

 

          • accompanies the dorsalis pedis artery

 

  • supply the skin on the adjacent sides of the first and second toes.

 

    • Tibial Nerve (L4–S3)
      • Descends through the popliteal fossa and then lies on the popliteus muscle.

 

  • Gives rise to three articular branches, which accompany genicular arteries to the knee joint.

 

      • Gives rise to the
        • medial sural cutaneous nerve
        • medial calcaneal branch to the skin of the heel and sole
        • articular branches to the ankle joint.

 

  • Terminates beneath the flexor retinaculum by dividing into the medial and lateral plantar nerves.

 

      • Medial Plantar Nerve
        • innervates abductor hallucis and flexor digitorum brevis muscles
        • Gives rise to common digital that supply
          • flexor hallucis brevis
          • first lumbrical
          • skin of the medial three and one-half toes.
      • Lateral Plantar Nerve

 

  • innervates the quadratus plantae and the abductor digiti minimi muscles.

 

        • Divides into a

 

  • superficial branch, which innervates the flexor digiti minimi brevis,

 

        • deep branch, which innervates the

 

  • plantar and dorsal interossei
  • lateral three lumbricals

 

          • adductor hallucis.

 

  • Surgical Anatomy
  • Damage to the obturator nerve

 

        • causes weakness of adduction and a lateral swinging of the limb during walking because of the unopposed abductors.
      • Damage to the femoral nerve
        • causes impaired flexion of the hip and impaired extension of the leg resulting from paralysis of the quadriceps femoris.
      • Injury to the superior gluteal nerve
        • causes  weakened abduction of the thigh by the gluteus medius
        • a disabling gluteus medius limp, and gluteal gait.
      • Damage to the sciatic nerve
        • causes impaired
          • extension at the hip
          • flexion at the knee
          • dorsiflexion and plantar flexion at the ankle,
          • inversion and eversion of the foot

 

  • peculiar gait because of increased flexion at the hip to lift the dropped foot off the ground.
  • Damage to the common peroneal (fibular) nerve

 

        • occur as a result of fracture of the head or neck of the fibula
        • The nerve damage results in
          • foot drop (loss of dorsiflexion)
          • loss of sensation on the dorsum of the foot and lateral aspect of the leg
          • causes paralysis of all muscles in the anterior and lateral compartments of the leg (dorsiflexor and evertor muscles of the foot).
      • Damage to the superficial peroneal (fibular) nerve
        • causes no foot drop
        • cause loss of eversion of the foot.

 

  • Damage to the deep peroneal (fibular) nerve

 

      • results in foot drop (loss of dorsiflexion)
      • causes characteristic high-stepping gait.
    • Damage to the tibial nerve  causes
      • loss of plantar flexion of the foot
      • impaired inversion resulting from paralysis of the tibialis posterior
      • causes a difficulty in getting the heel off the ground and a shuffling of the gait
      • It results in a characteristic clawing of the toes and sensory loss on the sole of the foot, affecting posture and locomotion.