FF - UE and LE Nerves

What nerve roots form the axillary nerve?

C5-C6

What muscles does the axillary nerve innervate?

Teres minor and deltoid

Motor supply of the Anterior deltoid:

Shoulder IR, flexion, horizontal adduction

Motor supply of the Posterior deltoid:

Shoulder ER, extension, horizontal abduction

Motor supply of the Acromial fibers:

Powerful shoulder abductors

Motor supply of the Teres minor:

Shoulder ER, extension, abduction, horizontal abduction

What movements are lost with an axillary nerve injury?

Shoulder abduction (especially >15°) and external rotation

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

Axillary Nerve Injury Presentation

"Square shoulder" due to deltoid atrophy, and sensory loss over lower deltoid

Radial Nerve Roots

C5-C8, T1

What muscles are primarily innervated by the radial nerve?

Triceps, brachioradialis, supinator, and all wrist/finger extensors

Main action of the radial nerve?

Elbow, wrist, and finger extension

What area of skin does the Lower Lateral Cutaneous Nerve of the Arm supply?

Skin of the lower half of the lateral side of the arm

What nerve supplies sensation to the back of the arm?

Posterior Cutaneous Nerve of the Arm

What area does the Posterior Cutaneous Nerve of the Arm innervate?

Skin of the posterior (back) aspect of the arm

What nerve supplies sensation to the back of the forearm?

Posterior Cutaneous Nerve of the Forearm.

What area does the Posterior Cutaneous Nerve of the Forearm innervate?

Skin of the posterior (back) aspect of the forearm.

What does the superficial branch of the radial nerve provide sensory innervation to?

Skin of the lateral half of the dorsum of the hand and the lateral 2½ digits (including the thumb)

The superficial branch of the radial nerve supplies sensation to which digits?

The thumb, index finger, middle finger, and lateral half of the ring finger on the dorsal hand

Which nerve supplies the dorsolateral hand and lateral 2½ digits?

Superficial branch of the radial nerve

Quick Memory Trick: Radial nerve =

"Back side + Thumb side"

Posterior arm →

Posterior forearm →

Dorsolateral hand →

Lateral 2½ digits →

Posterior arm → Posterior cutaneous nerve of arm

Posterior forearm → Posterior cutaneous nerve of forearm

Dorsolateral hand → Superficial radial branch

Lateral 2½ digits → Radial sensory distribution

Classic radial nerve injury?

Wrist drop

Tenderness distal to lateral epicondyle; pain reproduced by long finger extension

Radial Tunnel Syndrome

Branch of medial cord of brachial plexus ( (C7-T1) mainly C8-T1))

Ulnar nerve

What are the actions of the dorsal interossei (4 muscles)?

Abduction of the 2nd, 3rd, and 4th digits away from the middle finger

Mnemonic: DAB = Dorsal interossei ABduct

Which digits are abducted by the dorsal interossei?

Digits 2, 3, and 4 move away from the middle finger

What are the actions of the palmar interossei (3 muscles)?

Adduction of the 2nd, 4th, and 5th digits toward the middle finger

Flexion at the MCP joints

Extension at the IP joints

Mnemonic: PAD = Palmar interossei ADduct

Ulnar nerve motor supply

Dorsal Interossei (4)

Palmar Interossei (3)

Adductor Pollicis

Opponens Digiti Minimi

Flexor Digiti Minimi

Abductor Digiti Minimi

Flexor Pollicis Brevis

Flexor Digitorum Profundus (Medial half)

Flexor Carpi Ulnaris

Lumbricals- 3,4

Which digits are adducted by the palmar interossei?

Digits 2, 4, and 5 move toward the middle finger

What area does the palmar cutaneous branch of the ulnar nerve supply?

Skin of the medial ½ of the palm

Which nerve branch supplies sensation to the medial half of the palm?

Palmar cutaneous branch of the ulnar nerve

What area does the dorsal cutaneous branch of the ulnar nerve supply?

Skin of the dorsal aspect of the medial 1½ fingers

Which fingers receive sensory innervation from the dorsal cutaneous branch of the ulnar nerve?

5th digit (pinky)

Medial half of the 4th digit (ring finger)

What does the superficial branch of the ulnar nerve supply?

Sensation to the palmar surface of the 1½ medial digits

Which digits are supplied by the superficial branch of the ulnar nerve?

5th digit

Medial half of the 4th digit

What is the sensory distribution of the ulnar nerve in the hand?

Palmar side: medial 1½ digits

Dorsal side: medial 1½ digits

Medial palm: palmar cutaneous branch

Compression at cubital tunnel at elbow which leads to 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

Cubital Tunnel Syndrome

Sensory changes and progressive weakness of muscles innervated distal to the site

Guyon's Canal Syndrome

Ulnar Claw Hand Presentation

Hyperextension at 4th/5th MCP joints and flexion at IP joints

Formed from medial and lateral cord of

brachial plexus; nerve roots: C5-C8, T1

Median nerve

Median Nerve Motor Supply (Hand)

Thenar muscles (except adductor pollicis) and lateral two lumbricals

Median Nerve - Motor supply

Flexor Digitorum Profundus (radial half)

Flexor Pollicis Longus

Pronator Quadratus

Abductor Pollicis Brevis

Pronator Teres

Opponens Pollicis

Palmaris Longus

Lumbricals 1,2

Flexor Carpi Radialis

Flexor Digitorum Superficialis

Flexor Pollicis Brevis

What area does the palmar cutaneous branch of the median nerve supply?

Skin of the lateral ⅔ of the palm

Which nerve branch supplies sensation to the lateral two-thirds of the palm?

Palmar cutaneous branch of the median nerve

What areas do the palmar digital branches of the median nerve supply?

Palmar skin of the lateral 3½ digits

Dorsal tips of the 1st, 2nd, and 3rd fingers

Which digits receive sensory innervation from the palmar digital branches of the median nerve?

Thumb (1st digit)

Index finger (2nd digit)

Middle finger (3rd digit)

Lateral half of ring finger (½ of 4th digit)

Ape Hand Deformity Cause

Wasting of the thenar eminence due to median nerve palsy

Median nerve is compressed under the flexor retinaculum at the wrist

Carpal tunnel 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.

Pronator teres syndrome

Musculocutaneous Nerve Roots

C5-C7

Branch of the lateral cord of brachial plexus

Musculocutaneous Nerve Motor Supply

Biceps brachii, brachialis, and coracobrachialis

Musculocutaneous Nerve Sensory Supply

Lateral cutaneous nerve of the forearm

Suprascapular Nerve Roots & Motor

C5-C6; supplies supraspinatus and infraspinatus

Subscapular Nerve (upper and lower)

Branch of posterior cord of brachial plexus

Nerve Roots: C5-C6

Motor supply of subscapular nerve

Teres Major (Lower Subscapular Nerve)

Subscapularis (Both Upper & Lower

Subscapular Nerve)

Lateral Pectoral Nerve

Branch of lateral cord of brachial plexus

Nerve Roots: C5-C7

Motor supply of Lateral Pectoral Nerve

Pectoralis Major

Clavicular fibers

Sternocostal fibers

Medial Pectoral Nerve

Branch of medial cord of brachial plexus

Nerve Roots: C8, T1

Motor supply of Medial Pectoral Nerve

Pectoralis Minor

Long Thoracic Nerve Roots & Motor

C5-C7; supplies serratus anterior

Long Thoracic Nerve Injury Sign

Winged scapula

Thoracodorsal Nerve Roots & Motor

C6-C8 (posterior cord); supplies latissimus dorsi

Dorsal Scapular Nerve Roots & Motor

C5 (arise from roots of brachial plexus); supplies rhomboids and levator scapulae

Nerve to Subclavius

Nerve Roots: C5-C6

Upper trunk of brachial plexus

Which muscles perform scapular elevation?

Upper trapezius

Levator scapulae

Rhomboids

Which muscles perform scapular protraction?

Serratus anterior

Pectoralis minor

Pectoralis major

Which muscles perform scapular depression?

Serratus anterior

Pectoralis minor

Pectoralis major

Lower trapezius

Latissimus dorsi

Which muscles perform scapular retraction?

Trapezius

Rhomboids

Which muscles perform scapular downward rotation?

Levator scapulae

Rhomboids

Pectoralis minor

Which muscles perform scapular upward rotation?

Serratus anterior

Upper trapezius

Lower trapezius

Spinal Accessory Nerve (CN XI) Motor Supply

Trapezius and sternocleidomastoid

Superior Gluteal Nerve Roots & Motor

L4-S1; supplies gluteus medius, gluteus minimus, and tensor fasciae latae

Inferior Gluteal Nerve Roots & Motor

L5-S2; supplies gluteus maximus

Nerve to Piriformis (Ventral Rami of _____) and Motor

L5-S2

Piriformis

Obturator Nerve Roots

L2-L4

Obturator Nerve Motor Supply Anterior division

Adductor Longus and Brevis, gracilis

Obturator Nerve Motor Supply Posterior division

Obturator Externus & Adductor Magnus

Obturator Nerve - Sensory supply

Cutaneous branch of obturator nerve supplies skin of medial thigh

Nerve to Quadratus Femoris

L4-S1; Gemellus inferior and Quadratus Femoris

Nerve to Obturator Internus

Nerve Roots: L5-S2

Motor supply: Gemellus superior and Obturator Internus

Femoral Nerve Roots

L2-L4

Femoral Nerve Motor Supply

Rectus femoris, sartorius, pectineus, iliacus, and Vastus Medialis/Intermedius/Lateralis

Femoral Nerve - Sensory Supply

Medial Cutaneous Nerve of thigh

Intermediate Cutaneous Nerve of thigh

Saphenous Nerve

Saphenous Nerve Supply

Branch of femoral nerve supplying skin on the medial leg

Sciatic Nerve Roots

L4-S3

Sciatic Nerve Motor Supply

Hamstrings (semitendinosus, semimembranosus, biceps femoris) and adductor magnus

Herniated disc or bone spur that compresses the sciatic nerve and cause radiating pain

Sciatica

Piriformis spasm or tightness compresses the sciatic nerve

Piriformis Syndrome

Tibial Nerve Roots

L4-S3

Tibial Nerve Motor Supply (Leg)

Gastrocnemius, soleus, plantaris, popliteus, tibialis posterior, FHL, and FDL

Medial Plantar Nerve Motor Supply

Abductor hallucis, flexor hallucis brevis, flexor digitorum brevis, and 1st lumbrical

Lateral Plantar Nerve: Motor supply

Plantar Interossei, Dorsal Interossei, Quadratus plantae, Abductor Digiti Minimi, Lumbricals 2,3,4, Adductor Hallucis

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 - Sensory

Supplies skin over heel

Medial Plantar Nerve

Supplies skin on medial side of sole

Lateral Plantar Nerve

Supplies skin on lateral side of sole

Common Peroneal Nerve Root and Motor supply

Nerve Roots: L4-S2

Tibialis Anterior, Extensor Hallucis Longus, Extensor Digitorum Longus, Extensor Digitorum Brevis, Peroneus Tertius

Injury to the deep peroneal nerve results in

foot drop and unopposed eversion during gait

Deep Peroneal Nerve Roots

L4-S1