Neural anatomy map of lower extremities, necessary to solve waist and leg pain

Lumbar plexusLocated deep to the psoas major, its branches include iliohypogastric nerve, ilioinguinal nerve, reproductive Femoral nerve, lateral femoral cutaneous nerve, femoral nerve, and obturator nerve.

Sacral plexus is located behind the pelvis On both sides of the wall, anterior to the piriformis muscle. Branches include the superior gluteal, inferior gluteal, pudendal, posterior femoral cutaneous, and sciatic nerves.

lumbar plexus

1. Iliohypogastric nerve (mainly sensory nerve)

Cutaneous Branch: Lateral gluteus, skin of lower abdomen

Muscular branch: Muscles of the lower abdominal wall< /p>

2. Ilioinguinal nerve (mainly motor nerve)

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Muscular branches:Muscles of the lower abdominal wall

Cutaneous branch:Inguinal area and skin of scrotum or labia majora

3. Genitofemoral nerve

< strong>4. Lateral femoral cutaneous nerve

The paresthesia in this area may be the injury of the lateral femoral cutaneous nerve . Common is the area delineated by the dark blue line, more locations also extend into the area delineated by the light blue line.

Anatomy: The lateral femoral cutaneous nerve passes out from the lateral edge of the psoas major, passes through the deep surface of the inguinal ligament, distributes to the lateral femoral skin, and reaches near the knee joint.

5. Femoral nerve< /span>

Anatomy: In addition to the trunk of the sciatic nerve, the femoral nerve of the lower extremity is the largest branch, originating from the 2nd, 3rd, and 4th lumbar nerves, descending along the lateral border of the psoas major and the iliacus, It reaches the femoral triangle through the deep surface of the inguinal ligament, and the muscular branches are distributed to the anterior group of the thigh muscles, including the pectineus, sartorius and quadriceps. The cutaneous branch is distributed to the skin of the anterior part of the thigh, and the saphenous nerve enters the adductor tube and exits superficially on the medial side of the knee joint, and is distributed to the skin on the medial side of the calf and the medial border of the foot.

Muscles affected by nerve damage:< /strong>Iliacus, sartorius, pectineus, quadriceps

Common causes of nerve injury: Fracture of the pelvis or upper femur due to reduction of congenital dislocation of the hip or stress from delivery with forceps

Functional loss performance: Injury will lead to hip flexion, knee extension failure, decreased sensation in the front of the thigh and the inner side of the calf, and decreased knee reflex

6. Obturator nerve

This area may be an injury to the obturator nerve.

Anatomy: The obturator nerve goes out from the medial side of the psoas major and goes forward along the side wall of the pelvis, and passes through the obturator to exit the pelvic cavity. The muscular branch mainly controls the femoral adduction Muscle group and obturator external muscle, cutaneous branch distributed in the vastus medial skin

Muscles Affected by Nerve Injury:Obturator, Adductor< /p>

Common causes of nerve injury:Similar to the femoral nerve, the pressure comes from the pregnant uterus and dystocia

Main performance of loss of function: Difficulty crossing lower limbs, impairment of thigh adduction and abduction

Sacral Plexus

1. Superior gluteal nerve< /p>

2. Infragluteal nerve

3. Pudendal nerve

4. Posterior femoral cutaneous nerve< /strong>

The paresthesia in this area may be damage to the dorsal femoral cutaneous nerve.

Anatomical Distortion: The posterior femoral cutaneous nerve exits the subpiriformis foramen and descends to distribute the posterior part of the gluteal thigh and the skin of the popliteal fossa.

5. Sciatic nerve

Sensation in this area is provided by the aforementioned tibial nerve (medial sural cutaneous nerve, calcaneal branch, medial and lateral plantar nerve) area, lateral sural cutaneous nerve area, superficial peroneal nerve (dorsal medial cutaneous nerve, medial dorsum of foot) cutaneous nerve) area, sural nerve (calcaneal lateral branch, dorsal lateral cutaneous nerve) area, and deep peroneal nerve (medial branch of deep peroneal nerve) area are jointly composed of sciatic nerve innervation.

The sciatic nerve is the largest nerve in the human body. It starts from the spinal cord in the lumbosacral region, passes through the pelvis, and exits from the sciatic bone The greater foramen pierces, reaches the buttocks, and then descends along the back of the thigh to the feet. It manages the sensation and movement of the lower limbs. It consists of the lumbar nerve and the sacral nerve, which are the thickest of all nerves.

Anatomy: The sciatic nerve exits the pelvis to the buttocks through the subpiriformis foramen , go down in the deep side of the gluteus maximus, cross the obturator internal muscle, the upper and lower geminal muscles and the rear of the quadratus femoris in turn, innervate these muscles, and along the back of the adductor magnus, the semitendinosus, semimembranosus, and biceps femoris The sciatic nerve is divided into the tibial nerve and the common peroneal nerve before reaching the popliteal fossa, innervating all the muscles of the calf and foot, except the saphenous nerve The skin sensation of the calf and foot outside the area.

Muscles affected by nerve damage: hamstrings, adductor magnus

Common causes of nerve injury: Compression from a tight piriformis muscle; hip dislocation; femur fracture

Loss of major functions: Injuries result in inability to flex the knee and inability to flex the ankle and toe joints. Decreased sensation in the lower leg (except the anteromedial side) and foot, dystrophy, and decreased ankle-plantar reflex.

(1) Common peroneal nerve

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