Muscles of the extremeties and Levors

Wk 6

serratus anterior

protracts the scalular and rotates the glenoid cavity superiorly

pectoralis minor primarily

abducts arm

latissimus dorsi action

extension, adduction, medial rotation of humerus at shoulder joint

prime shoulder abductor

deltoid

what are the muscles of the rotator cuff

supraspinatus, infraspinatus, subscapularis, teres minorare the four muscles that stabilize the shoulder joint and assist with various arm movements.

biceps brachii function

supination and elbow flexion

primary elbow flexor deep to biceps

brachialis

triceps brachii action

extend elbow

muscle that pronates the forearm and assists elbow flexion

pronator teres

posterior forearm muscles generally

extend wrist and digits

flexor carpi radialis action

flex and abduct wrist

flexor digitorum profundus flexes

distal phalanges digits 2-5

extensor digitorum extends

medial four digits

supinator muscle works with

biceps brachii

flexor retinaculum helps form the

carpal tunnel

appendicular muscles control what regions

limbs, pectoral and pelvic girdles

distal attachment

is on the bone most likely to move

muscles that stabilize or move the scapular

pectoralis minor, serratus anterior, trapezius, levator scapulae, rhomboid minor, rhomboid major

pectoralis minor

lowers scapula and protracts shoulder

serratus anterior

protracts shoulder and rotates scapula so glenoid cavity moves superiorly

trapezius

elevates, retracts, and rotates scapula, lower fibers depress scapula

levator scapulae

elevates scapula medially, inferiorly rotates glenoid cavity

rhomboid minor

adducts and inferior rotation of scapula

rhomboid major

adducts and inferior rotation of scapula

prime movers of the glenohumeral joint/ arm

lattisimus dorsi and pectoralis major

latissimus dorsi

extends, adducts, and medially rotates shoulder

pectoralis major

flexes and adducts shoulder, rotates shoulder medially

muscles that move glenohumeral joint/arm

biceps brachii, triceps brachii medial/lateral head, triceps brachii long head, deltoid, coracobrachialis, teres major, rotator cuff msucles

biceps brachii

flexion at elbow and shoulder, supinates forearm at elbow

triceps brachii medial/lateral head

extends forearm at elbow, extends and adducts arm at shoulder

deltoid

abduction at shoulder

coracobrachialis

flexes and adducts at shoudler

teres major

extension and medially rotation at shoulder

rotator cuff muscles

supraspinatus, infraspinatus, teres minor, subscapularis

supraspinatus

abduction at shoulder

infraspinator

lateral rotation of shoulder

teres minor

lateral rotation and adduction at shoulder

subscapularis

medial rotation of shoulder

arm and forearm muscles that move the elbow joint/ forearm

anterior compartment (flexors): biceps brachii, brachialis, brachioradialis

posterior compartment (extensors): triceps brachii medial/lateral head, triceps brachii long head, anconeus

biceps brachii

flexion at elbow and shoulder, supinates forearm at elbow, anterior compartment of forearm

brachialis

flexes forearm at elbow, anterior compartment of forearm

brachioradialis

flexes forearm at elbow, anterior compartment of forearm

triceps brachii medial/ lateral head

extend forearm at elbow, posterior compartment of forearm

triceps brachii long head

extend forearm at elbow, extends and adducts arm at shoulder, posterior compartment of forearm

arm and forearm muscles that move the elbow joint/ forearm

anterior compartment: pronator teres, pronator quadratus

posterior compartment: supinator

pronator teres

pronates forearm and assists with elbow flexion, anterior compartment of forearm

supinator

supinates forearm, posterior compartment, works with biceps brachii to supinate forearm

forearm muscles that move wrist, hand, fingers

tendons of anterior compartment muscles pass over anterior surface of carpal bones, held in place by flexor retinaculum

tunnelis carpal

space between carpal bones and flexor retinaculum

extensor retinaculum

holds together the tendons of extensors

anterior forearm muscles

superficial layer: pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris

intermediate layer: flexor digitorum superficialis

deep layer: flexor pollicis longus, flexor digitorum profundus

pronator teres

pronates forearm and assists with elbow flexion

flexor carpi radialis

flexes and abducts hand at wrist

palmaris longus

flexes hand at wrist

flexor carpi ulnaris

flexes and adducts hand at wrist

flexor digitorum superficialis

flexes middle and proximal phalanges, flexes hadn at wrist

flexor digitorum profundus

flexes distal phalanges of digits 2-5, assists with flexion of hadn at wrist

if your left hand covers the medial epicondyle of your right arm, name the superficial anterior forearm muscles from lateral → medial

pronator teres, flexor carpi radialis, palmaris longus, flexor carpi radialis

posterior arm muscles

superficial layer: extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris

extensor carpi radialis longus and brevis

extends and abducts had at wrist

extensor digitorum

extends medial four digits, assists in wrist extension

extensor digiti minimi

extends the fifth digit

extensor carpi ulnaris

extends and adducts hand at wrist

spinal nerve problem indicates

damage to roots of brachial plexus

high shoulder trauma indicates

damage to trunks of brachial plexus

axillary level injury indicates

damage to cords of brachial plexus

nerve deficits indicate

damage to branches of brachial plexus

Erb’s palsy

lateral neck traction, birth injury or football, stingers

deficits: loss of shoulder abduction (deltoid), ER (infraspinatus), elbow flexion (biceps)

resolves in 6 weeks

Waiter’s tip

affected muscles: axillary and musculocutaneous nerve

forced shoulder depression causes

damage to upper trunk of brachial plexus

shoulder is traumatically pushed down while head is stretched the other way

common with repetative overhead heavy lifting

forced arm traction overhead causes

damage to lower trunk of brachial plexus

nerves and arm violently pulled one way and the head is stretched the other way

common with motorcycle crashes

shoulder dislocation causes

damage to axillary nerve of brachial plexus

midshaft humerus fracture causes

damage to radial nerve of brachial plexus

neck compression causes

damage to roots of brachial plexus

C5-T1 pinched/stingers

trunks of the brachial plexus

upper, middle, lower

upper trunk of brachial plexus

C5-C6

middle trunk of brachial plexus

C7

lower trunk of brachial plexus

C8-T1

trunk injuries

mimic root injuries but spare paraspinals

if there is a pattern of weakness in extensor or flexor muscles,

think division levela

anterior divisions

flexor compartments

posterior divisions

extensor compartments

common mechanisms of trunk injuries to brachial plexus

shouler depression trauma, heavy backpack compression, thoracic outlet syndrome

born with a sharp accromion? might

tear supraspinatous overtime

lower trap weakness? might

cause kyphosis

emg electromyograph

measures electroactivity of muscles to determine whether healthy functioning

what makes you human?

the ability to touch your fingers to your thumb

pinching of the medial nerve causes

carpel tunnelc

carpel tunnel is relieved via

cut flexor to make room for nerve

plump part of palm atrophies with

carpel tunnel syndrome

saturday night palsy

numbness or droop in the wrist due to compression of radial nerve, relief on its own

components of a levor

rigid structure, muscle that produces angular motion, fulcrum (joint), load of the body part being moved

first class lever

the fulcrum is in the middle of the effort and the loads

second class lever

the load is in the middle of the fulcrum and the effort

effort of fulcrum

direction of movement

third class levers

effort is in the middle between the fulcrum and the load

examples of first class levers

trapezius, triceps, scm

second class

gastroc/ soleus, brachioradialis, temporalis/masseter

third class examples

biceps, hamstrings/quads , deltoid

muscles of the anterior thigh compartment

psoas major, iliacus, sartorius, rectus femoris, fascia lata, tensor fascia latae

hip and thigh flexors

iliopsoas muscle

psoas major and iliacus share the same distal attachment