NPTE Final Frontier Upper & Lower Extremity Nerves PDF

The Upper Extremity & Lower Extremity Nerves  2 Axillary Nerve ► Branch of the posterior cord of brachial plexus ► Nerve roots: C5-C6 ► Motor supply: ►...

The Upper Extremity & Lower Extremity Nerves  2 Axillary Nerve ► Branch of the posterior cord of brachial plexus ► Nerve roots: C5-C6 ► Motor supply: ► Teres minor Action: Shoulder ER, extension, abduction, horizontal abduction ► Deltoid - Anterior deltoid: Shoulder IR, flexion, horizontal adduction - Posterior deltoid: Shoulder ER, extension, horizontal abduction - Acromial fibers: Powerful shoulder abductors NPTE Final Frontier  3 Axillary Nerve ► Sensory supply ► Axillary nerve becomes upper lateral cutaneous nerve of arm and supplies the skin covering the lower half of deltoid and upper part of long head of triceps NPTE Final Frontier  4 Causes of Injury of Axillary Nerve ► Axillary nerve can be injured due to: - Dislocation of shoulder - Fracture of surgical neck of humerus ► Effects: - "Square shoulder” from deltoid muscle atrophy - Sensory loss over lower half of deltoid NPTE Final Frontier  5 Radial Nerve ► Branch of posterior cord of brachial plexus ► Nerve Roots: C5-8, T1 ► Exits axilla via triangular Interval, travels down humerus in radial groove. ► At the elbow, the radial nerve pierces the lateral muscular septum anterior to the lateral epicondyle and passes under the origin of the extensor carpi radialis brevis; it then divides into a superficial and a deep branch. NPTE Final Frontier  6 Radial Nerve – Motor supply ► Triceps - Elbow extension ► Anconeus - Weak elbow extensor ► Brachioradialis - Elbow flexion in mid-prone position ► Supinator - Supination of forearm NPTE Final Frontier  7 Radial Nerve – Motor supply ► Extensor Carpi Radialis Longus ► Extensor Digiti Minimi - Action: Wrist extension, radial deviation - Action: 5th digit extension at MCP, IP ► Extensor Carpi Radialis Brevis ► Extensor Pollicis Longus - Action: Wrist extension, radial deviation - Action: 1st digit extension at CMC, IP ► Extensor Pollicis Brevis ► Extensor Carpi Ulnaris - Action: 1st digit extension at MCP, IP - Action: Wrist extension, ulnar deviation ► Extensor Indicis ► Extensor Digitorum - Action: 2nd digit extension, wrist - Action: 2-5th digits extension at MCP, IP, extension Wrist ► Abductor Pollicis Longus - Action: 1st digit abduction and extension at CMC joint NPTE Final Frontier  8 Radial Nerve – Motor NPTE Final Frontier  9 Radial Nerve – Sensory supply ► Lower Lateral Cutaneous Nerve of the Arm - Skin of lower half of lateral side of arm ► Posterior Cutaneous Nerve of the Arm - Skin of back of the arm ► Posterior Cutaneous Nerve of the Forearm - Skin of back of forearm ► Superficial Branch - Skin of lateral half of dorsum of hand, lateral two and half digits including thumb NPTE Final Frontier  10 Radial Nerve Injury ► Radial nerve can be injured in axilla, musculospiral groove, around radial neck ► Radial Tunnel Syndrome: - Tenderness in the extensor muscle mass of the forearm (distal to lateral epicondyle), long finger extension test reproduces pain ► Posterior interosseous nerve syndrome ► Wrist drop NPTE Final Frontier  11 Ulnar Nerve ► Branch of medial cord of brachial plexus ► Nerve Roots: C7-T1 (main contribution from C8-T1) ► Passes behind the medial epicondyle ► Pierces the flexor carpi ulnaris to enter forearm ► Superficial to flexor retinaculum ► Enters hand via Guyon’s canal/ tunnel NPTE Final Frontier  12 Ulnar Nerve – Motor supply ► Dorsal Interossei (4) ► Opponens Digiti Minimi - Action: Abduction of 2nd, 3rd, 4th digits - Action: Flexion of 5th metacarpal, away from middle finger lateral rotation producing opposition - Mnemonic: DAB ► Flexor Digiti Minimi ► Palmar Interossei (3) - Action: Flexion of little finger - Action: Adduction of 2nd, 4th, 5th digits towards middle finger, flexion of digit ► Abductor Digiti Minimi at MCP, extension at IP - Action: Abduction of little finger at - Mnemonic: PAD MCP joint ► Adductor Pollicis - Action: Adduction of thumb NPTE Final Frontier  13 Ulnar Nerve – Motor supply ► Flexor Pollicis Brevis - Action: Flexion of thumb ► Flexor Digitorum Profundus (Medial half) - Action: Flexion of DIP - Secondary: Flexion of joints of digits, finger, wrist ► Flexor Carpi Ulnaris - Action: Wrist flexion, ulnar deviation ► Lumbricals- 3,4 - Action: Flexion at MCP, extension at IP NPTE Final Frontier  14 Ulnar Nerve – Sensory supply ► Palmar Cutaneous Branch - Supplies medial ½ of palm ► Dorsal Cutaneous Branch - Supplies skin of dorsal aspect of medial one and half fingers ► Superficial Branch - Supplies ½ of 4th, 5th digit NPTE Final Frontier  15 Ulnar Nerve Lesion ► Cubital Tunnel Syndrome - Compression at cubital tunnel at elbow - Paralysis of flexor carpi ulnaris, flexor digitorum profundus (ulnar half), hypothenar eminence, interossei, and the third and fourth lumbrical muscles - All sensations affected - Inability to grip paper ► Guyon’s Canal Syndrome - Sensory changes and progressive weakness of muscles innervated distal to the site Ulnar Claw hand - Hyperextension at 4th,5th MCP, Flexion at 4th, 5th IP due to weakness of lumbricals and interossei NPTE Final Frontier  16 Ulnar Nerve Lesion NPTE Final Frontier  17 Median Nerve ► Formed from medial and lateral cord of brachial plexus ► Nerve Roots: C5-8, T1 ► Descends lateral to brachial artery ► Enters forearm between two heads of pronator teres muscle ► Enters hand via carpal tunnel NPTE Final Frontier  18 Median Nerve – Motor supply ► Flexor Digitorum Profundus (radial half) ► Pronator Teres - Action: Flexion of DIP, - Action: Pronation of forearm, elbow flexion - Secondary: Flexion of joints of digits, ► Opponens Pollicis finger, wrist - Action: Opposition of thumb ► Flexor Pollicis Longus ► Palmaris Longus - Action: Flexion of wrist - Action: Flexion of distal phalanx of thumb ► Lumbricals 1,2 - Action: Flexion of MCP and extension of IP ► Pronator Quadratus ► Flexor Carpi Radialis - Action: Pronation of forearm - Action: Wrist flexion, radial deviation ► Abductor Pollicis Brevis ► Flexor Digitorum Superficialis - Action: Flexion of PIP joint - Action: Abduction of thumb at MCP, CMC joint ► Flexor Pollicis Brevis - Action: Flexion of thumb NPTE Final Frontier  19 Median Nerve – Sensory supply ► Palmar Cutaneous Branch - Skin of lateral two-thirds of palm ► Palmar Digital Branches - Supplies dorsal tips of 1st, 2nd, & 3rd finger, palmar skin of lateral three and half fingers NPTE Final Frontier  20 Median Nerve Injuries ► Pronator teres syndrome - Hypertrophy of pronator teres muscle can compress the median nerve. Pronator teres remains normal, but the other muscles supplied by the median nerve and the sensory distribution is affected. ► Carpal tunnel syndrome - Median nerve is compressed under the flexor retinaculum at the wrist ► Ape hand deformity - Wasting of the thenar eminence of the hand occurs because of a median nerve palsy NPTE Final Frontier  21 Musculocutaneous Nerve ► Branch of the lateral cord of brachial plexus ► Nerve Root: C5-C7 ► Motor supply ► Biceps: - Action: Elbow flexion, forearm supination, flexion of arm ► Brachialis - Action: Elbow flexion ► Coracobrachialis - Action: Flexion of arm ► Sensory supply ► Lateral cutaneous nerve of forearm: supply the skin on lateral side of forearm NPTE Final Frontier  22 Suprascapular Nerve ► Arise from upper trunk of brachial plexus ► Nerve Roots: C5-C6 ► Motor supply ► Infraspinatus - Action: Lateral rotation and abduction of arm ► Supraspinatus - Action: Shoulder abduction up to 15 degrees NPTE Final Frontier  23 Subscapular Nerve (Upper & Lower) ► Branch of posterior cord of brachial plexus ► Nerve Roots: C5-C6 ► Motor supply ► Teres Major (Lower Subscapular Nerve) - Action: Shoulder medial rotation, extension, adduction ► Subscapularis (Both Upper & Lower Subscapular Nerve) - Action: Shoulder medial rotation (when arm is by side), adduction NPTE Final Frontier  24 Lateral Pectoral Nerve ► Branch of lateral cord of brachial plexus ► Nerve Roots: C5-C7 ► Motor supply ► Pectoralis Major - Action: Medial rotation, adduction, horizontal adduction, scapular protraction, depression ► - Clavicular fibers: Shoulder flexion - Sternocostal fibers: Shoulder extension NPTE Final Frontier  25 Medial Pectoral Nerve ► Branch of medial cord of brachial plexus ► Nerve Roots: C8, T1 ► Motor supply ► Pectoralis Minor - Action: Downward rotation of scapula, scapular protraction, depression NPTE Final Frontier  26 Long Thoracic Nerve ► Arise from roots of brachial plexus ► Nerve Roots: C5,C6,C7 ► Motor supply ► Serratus Anterior - Action: Upward rotation of scapula, scapular protraction, depression ► Injury can cause: - Winged scapula NPTE Final Frontier  27 Thoracodorsal Nerve ► Branch of posterior cord of brachial plexus ► Nerve Roots: C6-C8 ► Motor supply ► Latissimus Dorsi - Action: Shoulder extension, adduction, medial rotation, depression and protraction of scapula NPTE Final Frontier  28 Dorsal Scapular Nerve ► Arise from root of brachial plexus ► Nerve root- C5 ► Motor supply ► Rhomboid Minor - Action: Scapular elevation, retraction, downward rotation ► Rhomboid Major - Action: Scapular elevation, retraction, downward rotation ► Levator Scapulae - Action: Scapular elevation, downward rotation NPTE Final Frontier  29 Nerve to Subclavius ► Arise from upper trunk of brachial plexus ► Nerve Roots: C5-C6 ► Motor supply ► Subclavius - Action: Depress & stabilize clavicle NPTE Final Frontier  30 Scapular Movements & Muscles ► Scapular Elevation ► Scapular Retraction - Upper trapezius, levator scapulae, - Trapezius, rhomboids rhomboids ► Scapular Downward Rotation ► Scapular Protraction - Levator scapula, rhomboids, - Serratus anterior, pectoralis minor pectoralis minor and major ► Scapular Upward Rotation ► Scapular Depression - Serratus anterior, trapezius (upper - Serratus anterior, pectoralis minor and lower fibers) and major, lower trapezius, latissimus dorsi NPTE Final Frontier  31 Scapular Movement Continued NPTE Final Frontier  32 Scapular Movement Continued NPTE Final Frontier  33 Spinal Accessory Nerve (CN XI) ► Motor supply ► Trapezius - Action: Upper fibers- scapula elevation, Middle fibers- Retraction, Lower fibers- depression, upper and lower fibers-Upward rotation ► Sternocleidomastoid - Action: Cervical lateral flexion and opposite side rotation NPTE Final Frontier  34 Superior Gluteal Nerve ► Nerve Roots: L4-S1 ► Motor supply ► Gluteus Medius - Action: Abduction of hip - Assist in medial and lateral rotation of hip ► Gluteus Minimuss - Action: Abduction of hip ► Tensor Fascia Latae - Action: Flexion, abduction, medial rotation of hip NPTE Final Frontier  35 Inferior Gluteal Nerve ► Nerve Roots: L5-S2 ► Motor supply ► Gluteus Maximus - Action: Hip extension & external rotation - Secondary action: Hip adduction NPTE Final Frontier  36 Nerve to Piriformis (Ventral Rami of L5-S2) ► Nerve Roots: L5-S2 ► Motor supply ► Piriformis - Action: Abduction and lateral rotation of hip NPTE Final Frontier  37 Obturator Nerve ► Nerve Roots: L2-L4 ► Enters the thigh by passing through the obturator canal ► Bifurcates into anterior & posterior divisions ► Motor supply of anterior division ► Adductor Longus - Action: Hip adduction, flexion, medial rotation ► Adductor Brevis - Action: Hip adduction, flexion, medial rotation ► Gracilis - Action: Hip flexion, medial rotation, adduction NPTE Final Frontier  38 Obturator Nerve ► Motor supply of posterior division ► Obturator Externus - Action: Hip lateral rotation, adduction ► Adductor Magnus - Action: Hip adduction, extension, medial rotation NPTE Final Frontier  39 Obturator Nerve – Sensory supply ► Cutaneous branch of obturator nerve supplies skin of medial thigh NPTE Final Frontier  40 Nerve to Quadratus Femoris ► Nerve Roots: L4-S1 ► Motor supply ► Gemellus inferior - Action: Lateral rotation of hip ► Quadratus Femoris - Action: Lateral rotation & adduction of hip NPTE Final Frontier  41 Nerve to Obturator Internus ► Nerve Roots: L5-S2 ► Motor supply ► Gemellus superior - Action: Lateral rotation of hip ► Obturator Internus - Action: Lateral rotation of hip NPTE Final Frontier  42 Sciatic Nerve ► Largest branch of sacral plexus ► Semitendinosus ► Nerve Roots: L4-S3 - Action: Knee flexion, hip extension, medial rotation of flexed leg in non– ► Motor supply weight bearing ► Biceps Femoris ► Semimembranosus - Action: Knee flexion, hip extension, - Action: Knee flexion, hip extension, lateral rotation of flexed leg in non– medial rotation of flexed leg in non– weight bearing weight bearing ► Adductor Magnus - Action: Hip adduction, extension, medial rotation NPTE Final Frontier  43 Sciatic Nerve ► Sciatica - Herniated disc or bone spur that compresses the sciatic nerve and cause radiating pain ► Piriformis Syndrome - Piriformis spasm or tightness compresses the sciatic nerve NPTE Final Frontier  44 Sciatic Nerve Continued NPTE Final Frontier  45 Femoral Nerve ► Nerve Root: L2-L4 ► Pectineus ► Passes through femoral triangle along - Action: Hip flexion, adduction, with femoral artery medial rotation ► Motor supply ► Sartorius - Action: Hip flexion, abduction, lateral ► Iliacus rotation, knee flexion - Action: Hip flexion - Works with psoas major & psoas ► Rectus Femoris minor - Action: Hip flexion, knee extension ► Vastus Medialis/Intermedius/Lateralis - Action: Knee extension NPTE Final Frontier  46 Femoral Nerve – Sensory Supply ► Medial Cutaneous Nerve of thigh - Branch of anterior division of femoral nerve - Supplies the skin on medial side of lower two third of thigh ► Intermediate Cutaneous Nerve of thigh - Branch of anterior division of femoral nerve - Supplies the skin on front of thigh ► Saphenous Nerve - Branch of posterior division of femoral nerve - Supplies the skin on the medial side of leg NPTE Final Frontier  47 Tibial Nerve ► Terminal branch of sciatic nerve ► Deep muscles: ► Nerve Root: L4-S3 - Popliteus - Action: Knee flexion, medial rotation of ► Motor supply flexed leg in non–weight bearing ► Superficial muscles: - Gastrocnemius - Tibialis Posterior - Action: Plantarflexion, knee flexion - Action: Plantarflexion, Inversion - Soleus - Flexor Hallucis Longus - Action: Plantarflexion - Action: Flexion of great toe, plantarflexion, Inversion - Plantaris - Action: Slight knee flexion, - Flexor Digitorum Longus Plantarflexion - Action: 2-5 toes flexion, plantarflexion, inversion NPTE Final Frontier  48 Tarsal Tunnel Syndrome NPTE Final Frontier  49 Tibial Nerve Branch – Medial Plantar Nerve: Motor supply ► Medial Plantar nerve ► Abductor Hallucis - Action: Great toe abduction ► Flexor Hallucis Brevis - Action: 1st toe flexion ► Flexor Digitorum Brevis - Action: 2-4th toe flexion ► Lumbrical 1 -Action: MTP flexion, IP extension NPTE Final Frontier  50 Tibial Nerve Branch – Lateral Plantar Nerve: Motor supply ► Plantar Interossei ► Abductor Digiti Minimi - Actions: Adduction of 3-5 toes, - Actions: 5th Toe abduction and flexion at MTP joints flexion ► Dorsal Interossei ► Lumbricals 2,3,4 - Actions: Abduction of 2-4 toes, - Actions: MTP flexion, IP extension flexion at MTP joints ► Adductor Hallucis ► Quadratus plantae - Action: Adduction of great toe - Actions: Flexion of toes NPTE Final Frontier  51 Tibial Nerve – Sensory Branches ► Branch from tibial Nerve and common peroneal nerve forms the sural nerve which supplies the skin over lower posterolateral leg ► Medial Calcaneal Branches - Supplies skin over heel ► Medial Plantar Nerve - Supplies skin on medial side of sole ► Lateral Plantar Nerve - Supplies skin on lateral side of sole NPTE Final Frontier  52 Common Peroneal Nerve ► Nerve Roots: L4-S2 ► Originates from sciatic nerve at popliteal fossa ► Bifurcates just below the neck of the fibula into: - Superficial peroneal nerve - Deep peroneal nerve NPTE Final Frontier  53 Deep Peroneal Nerve – Motor supply ► Nerve Roots: L4-S1 ► Extensor Digitorum Brevis ► Tibialis Anterior - Action: Toes extension - Dorsiflexion, inversion ► Peroneus Tertius ► Extensor Hallucis Longus - Action: Ankle dorsiflexion, eversion - Action: 1st toe extension, ankle ► Injury to the deep peroneal nerve dorsiflexion, inversion results in foot drop and unopposed ► Extensor Digitorum Longus eversion during gait - Action: Toe extension, ankle dorsiflexion, eversion NPTE Final Frontier  54 Superficial Peroneal Nerve – Motor supply ► Nerve Roots: L4-S2 ► Peroneus Longus - Action: Plantarflexion, eversion ► Peroneus Brevis - Action: Plantarflexion, eversion NPTE Final Frontier  55 Superficial & Deep Peroneal Nerves – Sensory Supply ► Deep Peroneal Nerve: - Webbing between 1st & 2nd toes of foot on the dorsal surface ► Superficial Peroneal Nerve: - Dorsum of foot (Except webbing between 1st & 2nd toes) and anterolateral part of lower leg NPTE Final Frontier