Clinical manifestations of major nerve injury
ulnar claw radial drooping wrist median hand like an ape
Axillary injury square shoulder Femoral injury quadriplegia
tibial injury hooked foot inferior peroneal inversion
The median nerve (C6-T1) is formed in the axilla by the lateral and medial bundles of the brachial plexus. It travels along the biceps muscle in the arm, descends to the elbow fossa, passes between the two heads of the anterior circular muscle, travels between the superficial and deep flexors of the middle finger of the forearm, reaches the carpal tunnel, passes through the deep surface of the palmar tendon membrane to the palm of the hand, and divides into several branches of the common palmar nerve. The nerve runs along both sides of the finger to the tip of the finger. Hou Mingming, Department of Pain, Guilin People’s Hospital
In the arm, it coincides with the brachial artery; in the forearm, it is the line from the midpoint of the line connecting the medial epicondyle of the humerus and the biceps tendon to the slightly lateral line of the midpoint of the distal transverse stripe of the anterior wrist area. The median nerve, when passing between the two heads of the pronator teres, sends motor branches to innervate the following muscles: (1) the pronator teres, whose function is to rotate the forearm forward; (2) the radial carpal flexor, whose function is to flex the hand radially and flex the wrist; (3) the palmaris longus, whose function is to flex the wrist; and (4) the superficial finger flexor, whose function is to flex the middle phalanges of the index finger, middle finger, ring finger, and little finger. The median nerve, after passing between the two heads of the pronator teres, emits the anterior interosseous nerve, which innervates the following muscles: (1) the long thumb flexor, whose function is to flex the terminal phalanx of the thumb; (2) the deep flexor of the 1st and 2nd fingers, whose function is to flex the terminal phalanges of the index finger and middle finger; and (3) the pronator teres, whose function is to rotate the forearm anteriorly. At the distal end of the carpal tunnel, the median nerve innervates: (1) the short thumb adductor, whose function is to abduct the palm of the thumb; (2) the opposite thumb palmaris, whose function is to bring the palm of the thumb to the opposite side; (3) the superficial head of the short thumb flexor, whose function is to flex the proximal phalanx of the thumb; and (4) the 1st and 2nd earthworms, whose function is to flex the proximal phalanx of the index finger and middle finger and to straighten the distal two phalanges of the index finger. Sensory branches are located in the radial half of the skin of the palm, the radial half of the skin of the thumb, index finger, middle finger, and ring finger, and over the skin of the metacarpophalangeal joint of the corresponding fingers and the skin of the dorsal surface of the radial middle and terminal phalanges of the index finger, middle finger, and ring finger. Injury to the median nerve in the arm can involve all branches, manifested as the forearm can not be rotated forward, wrist flexion weakness, thumb and index finger can not be flexed, thumb can not be palmar, interphalangeal muscle atrophy, palm flat, called “ape hand”. Sensory impairment is evident in the terminal segments of the thumb, index finger and middle finger. Vasoconstriction and nutritional deficits may also be evident.
The radial nerve is formed by the anterior branch of the 5th to 8th pair of cervical nerves and the 1st pair of thoracic nerves entering the posterior bundle. It is located in the axilla just posterior to the axillary artery and runs outward with the deep brachial artery, first between the long head of the triceps muscle and the medial head, then rotates outward along the radial nerve groove around the dorsal aspect of the middle humerus, penetrating the lateral interval above the lateral epicondyle of the humerus to between the brachialis and the brachioradialis, where it divides into two branches, superficial and deep. The main motor impairment after injury is paralysis of the forearm extensor muscles, which is manifested by lifting the forearm in a The main motor impairment after the injury is the paralysis of the forearm extensor muscle, which is manifested as “hanging wrist” when lifting the forearm. Sensory impairment is most obvious in the skin of the “tiger’s mouth area” at the back of the 1st and 2nd metacarpal space. In the case of radial neck fracture, the deep branch of the radial nerve can also be injured, and the main symptom is weak wrist extension and inability to extend the fingers.
The radial nerve is located at the intersection of the lower edge of the posterior axillary crease and the arm, diagonally across the posterior humerus to the line of the external epicondyle of the humerus.
What are the symptoms of radial nerve injury? (1) Movement: When the radial nerve of the upper arm is injured, the extensor muscles are extensively paralyzed, and the triceps brachii, brachioradialis, radial long and short wrist extensors, posterior rotator, extensor digitorum generalis, ulnar wrist extensors, and the intrinsic extensor muscles of the index and little finger are paralyzed. Therefore, there is wrist ptosis, thumb and fingers ptosis, inability to extend the metacarpophalangeal joint, anterior rotation deformity of the forearm, inability to rotate posteriorly, and thumb inversion deformity. Examination of the triceps and wrist extensor muscles should be performed in the antigravity direction. The thumb loses abduction, cannot stabilize the metacarpophalangeal joint, and the thumb is severely dysfunctional. Movement of the wrist to both sides is difficult due to paralysis of the ulnar wrist extensor and radial wrist extensor long and short muscles. Atrophy of the dorsal forearm muscles was obvious. In the dorsal forearm radial nerve injury mostly interosseous dorsal nerve injury, sensation and triceps, posterior elbow muscle is not affected, and radial long wrist extensor is good. Other extensor muscles are paralyzed. (2) sensory: radial nerve injury, the dorsal radial half of the hand, radial two and a half fingers, the upper arm and the posterior forearm sensory impairment
The ulnar nerve (C7-T1) originates from the medial bundle of the brachial plexus, descends along the medial aspect of the brachial artery, turns to the back of the arm below the stop of the deltoid muscle, then travels to the ulnar nerve sulcus, then passes down through the ulnar carpal flexor to the medial aspect of the forearm palmar surface, and continues to descend between the ulnar carpal flexor and the deep finger flexor, medial to the ulnar artery to reach the wrist. At the wrist, the ulnar nerve enters the palm of the hand lateral to the carpal bone through the superficial surface of the flexor support band and the deep surface of the palmar tendon membrane.
From the apex of the axilla, it passes between the medial epicondyle of the humerus and the ulnar eminence to the line of the radial margin of the pisiform bone. The branch of the ulnar nerve in the forearm innervates the ulnar carpal flexors (flexion of the wrist to the ulnar side), the deep flexors of the 3rd and 4th fingers (flexion of the terminal phalanges of the 4th and 5th fingers), the short palmar muscles (skin muscles of the proximal ulnar side of the hand), the little finger extensors (abduction of the little finger), the little finger to palmar muscles (little finger to palm), the little finger flexors (flexion of the little finger), the 3rd and 4th earth muscles (flexion of the metacarpophalangeal joints of the 4th and 5th fingers and extension of the proximal interphalangeal joints), the interosseous muscles (metacarpophalangeal joint flexion and proximal interphalangeal joint extension), thumb retractor (thumb palmar retraction) and thumb short flexor deep head (thumb 1st knuckle flexion). The sensory branches emanating from the ulnar nerve are: (1) the metacarpal branch, which is distributed on the skin of the surface of the lesser trochanter; (2) the dorsal dermal branch, which is distributed on the ulnar side of the back of the hand and the skin of the ulnar half of the back of the little finger and ring finger; (3) the terminal superficial dermal branch, which is distributed on the distal skin of the ulnar side of the hand and the skin of the ulnar palmar surface of the little finger and ring finger. Weak internal retraction, obvious atrophy of the interosseous muscle and interosseous muscle, inability to bring the fingers together, hyperextension of the metacarpophalangeal joints, bending of the interphalangeal joints of the 4th and 5th fingers, called “claw-shaped hand”, and sensory impairment mainly on the medial edge of the hand. The main trunk of the ulnar nerve in the forearm travels superficially through the flexor support zone, accompanied by the ulnar side of the ulnar artery into the palm of the hand, and is divided into two branches, superficial and deep, below the pea bone.
The sciatic nerve is the thickest nerve in the body, starting from the spinal cord in the lumbosacral region, passing through the pelvis and exiting through the foramen magnum to reach the buttocks, and then descending along the back of the thigh to the foot. It manages the sensation and movement of the lower extremities and consists of the lumbar and sacral nerves. What is the distribution of the sciatic nerve? It comes from the lumbar 4 to lumbar 5 nerves and the sacral 1 to sacral 3 nerve roots. It is the thickest of all nerves. The sciatic nerve exits the pelvis to the buttocks through the inferior foramen of the pear-shaped muscle, travels downward in the deep side of the gluteus maximus muscle, crosses the closed inner muscle, the upper and lower seed muscles and the posterior aspect of the femoral square muscle in turn, innervates these muscles, and descends along the back of the great retractor muscle, between the semitendinosus, semimembranosus and biceps femoris muscles, sending out muscle branches to the flexors of the thigh on the way. Before it reaches the fossa, it divides into the tibial and common peroneal nerves, which innervate all the muscles of the calf and foot as well as the skin sensation of the calf and foot except for the saphenous innervation area. Sciatica is the main symptom of lumbar disc herniation, and the sciatic nerve is actually composed of the common peroneal nerve and the tibial nerve. These two nerves run from the beginning to the ? Above the fossa, the two nerves are enclosed by a sheath of connective tissue, but the fibers of the two nerves are not cross-linked together. The majority of the sciatic nerve exits the pelvis to the buttocks via the inferior foramen of the pear muscle. It then descends vertically outward between the greater trochanter and the sciatic tuberosity to the posterior femur. Pain due to the sciatic nerve or other parts that cross the pear muscle and are affected by muscle contraction and compression is called pear muscle syndrome. Related Diseases – Sciatica It is a group of painful symptoms that occur along the sciatic nerve pathway, namely the lumbar, gluteal, posterior thigh, posterior lateral calf, and lateral foot. According to the location of the lesion, there are two types of sciatica: radicular and dry sciatica. The former is mostly seen in radicular sciatica where the lesion is located in the spinal canal, and the most common cause is lumbar disc herniation, followed by intraspinal tumor, lumbar tuberculosis, and lumbosacral radiculitis. In dry sciatica, the lesion is mainly located on the extracanalicular sciatic nerve stroke, and the etiology includes skeletal arthritis, intrapelvic tumor, uterine compression in pregnancy, gluteal trauma, pear-shaped muscle syndrome, improper gluteal muscle injection, and diabetes mellitus.
Stroke, branches and distribution of the tibial nerve
The tibial nerve is a direct continuation of the sciatic nerve trunk and travels with the N vessels in the N fossa, descends through the deep surface of the flounder muscle in the lower leg with the posterior tibial artery, passes behind the medial ankle, and divides into the medial plantar nerve and the lateral plantar nerve in the deep surface of the flexor support zone into the sole of the foot. The medial plantar nerve, through the deep surface of the bunion muscle, runs along the medial side of the plantar, distributing in the medial group of the plantar muscles and the skin of the medial and medial three halves of the metatarsal surface of the plantar. The lateral plantar nerve, which passes through the deep surface of the bunions and the short toe flexors to the lateral aspect of the plantar aspect of the foot, is distributed to the middle and lateral groups of the plantar muscles and to the skin of the lateral and lateral one half toe plantar surface of the foot. The tibial nerve also gives off muscular branches in the N fossa and calf to innervate the posterior group of the calf muscle.
The tibial nerve gives off the medial peroneal cutaneous nerve, which travels down with the lesser saphenous vein and anastomoses with the lateral peroneal cutaneous nerve (from the common peroneal nerve) in the lower calf to form the peroneal nerve, which arches forward through the posterior aspect of the lateral ankle and distributes to the skin of the dorsum of the foot and the lateral margin of the little toe.
Injury manifestations
The main motor impairment of tibial nerve injury is the inability to plantar flex the foot, weak inversion, and inability to stand on the toes. Due to the excessive stretching of the anterolateral group of calf muscles, the foot is dorsiflexed and externally turned, resulting in a “hooked foot” deformity. The sensory impairment area is mainly on the plantar surface of the foot. Femoral supracondylar fractures and knee dislocations can easily damage the tibial nerve, causing paralysis of the posterior calf flexors and intrinsic plantar muscles, resulting in plantar flexion, inversion, inversion of the foot, plantar flexion, abduction and adduction of the toes, and sensory impairment of the posterior calf, dorsolateral foot, lateral heel and plantar surface of the foot.
Peroneal nerve damage The common peroneal nerve branches out from the sciatic nerve above the N fossa, bypasses the head of the fibula and reaches the anterior part of the calf, branches out into the lateral peroneal cutaneous nerve, which is distributed on the lateral side of the calf, and then forms the superficial peroneal nerve and the deep peroneal nerve. The superficial peroneal nerve innervates the peroneus longus and peroneus shortus muscles and divides into the dorsal medial cutaneous nerve of the foot and the middle cutaneous nerve of the foot, which are distributed on the dorsal skin of the 2-5 toes. The deep peroneal nerve innervates the anterior tibial muscle, the long extensor (of the mother of the foot), the short extensor (of the mother of the foot), and the short toe extensor, and divides into dermal branches to the dorsal aspect of the 1st and 2nd interdigital toes. Injury to the common peroneal nerve causes paralysis and atrophy of the peroneal and tibialis anterior muscles, and the patient is unable to extend the foot, lift the foot, raise the toes and extensor the foot, and has a horseshoe foot. When walking, the patient lifts the foot high, causing excessive flexion of the hip and knee joints, and when the foot hits the ground, the toe drops first, followed by landing with the whole foot and plantar, resembling the gait of a horse or a chicken, or called the cross-threshold gait. Sensory deficits are distributed in the anterolateral calf and dorsum of the foot, including the first toe gap. The Achilles tendon reflex is not affected. The common peroneal nerve is superficially located in the upper part of the fibula and is susceptible to damage by external factors such as impingement, pinching, compression, freezing, etc. It may also be involved by metabolic disorders (diabetes), connective tissue disease (polyarteritis nodosa), and leprosy. Treatment should be tailored to the cause of the injury. Physiotherapy, electrical stimulation, acupuncture, body therapy and B vitamins can be given to promote the recovery of nerve function.