<<

This document was created by Alex Yartsev ([email protected]); if I have used your data or images and forgot to reference you, please email me. segments, and Dermatomes and Myotomes of the upper Myotomes of the , and the muscles they influence A is the group of muscles supplied by one spinal segment Brachii Brachialis Flexion of the C5 Coracobrachialis “five six, pick up sticks” Deltoid Also abduction and internal rotation of the Teres Major Infraspinatus C6 Supraspinatus muscles Subscapularis Teres minor Brachii Extension of the arm Extensor Carpi Radialis Brevis Extension of the C6 Extensor Carpi Radialis Longus and the Extensor Carpi Ulnaris Except the pinky. The pinky is Extensor Digitorum extended by the C7-C8 segment; C7 Extensor Indicis but its still attached to the other Extensor Pollicis Longus extensor by a Extensor Pollicis Brevis ligamentous band, so weak extension can still occur Palmaris Longus Flexion of the Flexor Carpi Radialis

Pronator teres Supinator Abductor Pollicis Longus

Anconeus C7 Extensor Digiti Minimi Flexion of the fingers…again, C8 Flexor Digitorum Profundus except the pinky . The pinky is Flexor Digitorum Superficialis flexed by flexor digiti minimi – C8 and T1

Abductor Pollicis Brevis Adductor Pollicis Thumb movements: Flexor Pollicis Brevis Everything except extension C8 Flexor Pollicis Longus

Flexor Digiti Minimi Flexion, abduction, opposition T1 Abductor Digiti Minimi of the pinky finger Opponens Digiti Minimi So, all the hypothenar muscles.

Interossei Abduction and Adduction of the fingers Lumbricals

Palmaris brevis Pronator Teres Flexor Carpi Ulnaris

This document was created by Alex Yartsev ([email protected]); if I have used your data or images and forgot to reference you, please email me.

Segmental supply to arm movements and reflexes

Shoulder Flexion, abduction, external rotation C5

Extension, adduction, internal rotation C6 C7 C8

Elbow Flexion; BICEPS REFLEX C5 C6

Flexion; TRICEPS REFLEX C6 C7 C8

Forearm Supination C6 Pronation C7 C8

Wrist

Flexion C6 C7 C8

Extension C6 C7 C8

Fingers and Thumb- long tendons

Flexion C7 C8 Extension C7 C8

Small Muscles of the Including some thenar and all hypothenar All movements T1

In summary; Small muscles are ONLY T1 Supination is ONLY C6 Shoulder abduction, extension and external rotation is ONLY C5 C7 and C8 participate in just about everything.

This document was created by Alex Yartsev ([email protected]); if I have used your data or images and forgot to reference you, please email me. Dermatomes of the Upper Limb

DERMATOMAL DISTRIBUTION

5 C4 C6 C5 C6

T1

T2

C8 6

6

C7 7 8

8 7

AREAS OF SHARP DEMARCATION: o Anteriorly, C5 abuts T1 up until the wrist. o T1 is the lonely thoracic dermatome which runs all the way down the anterior arm o C5 is the shoulder o C6 is the thumb o C7 is the index and o C8 is the ring and

References: Moore’s Clinically Oriented Anatomy 5th edition