HK 4250 exam 2 sg

GH joint flexion PA muscles

anterior deltoid, coracobrachialis, pec major clavicular

GH joint extension PA muscles

posterior deltoid, teres major, latissimus dorsi

GH joint abduction PA muscles

middle deltoid and supraspinatus

GH joint adduction PA muscles

teres major, latissimus dorsi, pec major sternal

GH joint internal rotation PA muscles

subscapularis, teres major, latissimus dorsi, pec major clavicular, pec major sternal

GH joint external rotation PA muscles

infraspinatus and teres major

GH joint horizontal abduction PA muscles

posterior deltoid

GH joint horizontal adduction PA muscles

anterior deltoid, pec major clavicular, pec major sternal

ST joint elevation PA muscles

upper trapezius, rhomboids, levator scapula

ST joint depression PA muscles

lower trapezius, pec minor

ST joint abduction (protraction) PA muscles

serratus anterior

ST joint adduction (retraction) PA muscles

middle trapezius and rhomboids

ST joint upward rotation PA muscles

serratus anterior, upper trapezius, lower trapezius

ST joint downward rotation PA muscles

levator scapula

ST joint upward tilt PA muscles

pec minor

HU joint flexion PA muscles

biceps, brachialis, brachioradialis

HU joint extension PA muscles

triceps and anconeus

proximal and distal RU joint pronation PA muscles

pronator teres and pronator quadratus

proximal and distal RU joint supination PA muscles

biceps and supinator

radiocarpal joint flexion PA muscles

flexor carpi radialis, flexor carpi ulnaris, palmaris longus

radiocarpal joint extension PA muscles

ext carpi radialis longus, ext carpi radialis brevis, ext carpi ulnaris

radiocarpal joint radial deviation PA muscles

flexor carpi radialis, ext carpi radialis longus

radiocarpal joint ulnar deviation PA muscles

flexor carpi ulnaris and ext carpi ulnaris

MCP joint flexion PA muscles

lumbricales and flexor digiti minimi

MCP joint extension PA muscles

ext digitorum, ext indicis, ext digiti minimi

MCP joint abduction PA muscles

dorsal interossei (DABs) and abd digiti minimi

MCP joint of fingers adduction PA muscles

palmar interossei (PADs) and add pollicis

CMC joint of the pinky finger opposition PA muscles

opponens digiti minimi

PIP joints of the thumb and fingers flexion PA muscles

flexor digitorum superficialis

PIP joints of the thumb and fingers extension PA muscles

ext digitorum, ext indicis, ext digiti minimi, lumbricales

DIP joints of the thumb and fingers flexion PA muscles

flexor digitorum profundus

DIP joints of the thumb and fingers extension PA muscles

ext digitorum, ext indicis, ext digiti minimi, lumbricales

MCP joint of thumb flexion PA muscles

flexor pollicis brevis

MCP joint of thumb extension PA muscles

ext pollicis brevis

MCP joint of thumb abduction PA muscles

abd pollicis brevis

MCP joint of thumb adduction PA muscles

add pollicis

IP joint of thumb flexion PA muscles

flexor pollicis longus

IP joint of thumb extension PA muscles

ext pollicis longus

CMC of thumb flexion PA muscles

flexor pollicis brevis

CMC of thumb extension PA muscles

ext pollicis brevis and abd pollicis longus

CMC of thumb abduction PA muscles

ext pollicis brevis, abd pollicis longus, abd pollicis brevis

CMC of thumb adduction PA muscles

add pollicis

CMC of thumb opposition PA muscles

opponens pollicis

bones that form the shoulder complex

sternum, clavicle, scapula, humerus

joints that form the shoulder complex

SC, AC, ST, GH

functions of clavicle

-site for muscle attachments

-protects underlying nerves and blood vessels

-contributes to increased ROM of shoulder

-helps transmit muscle force to scapula

articulations of the clavicle

SC and AC joints

articulations of the SC joint

clavicle, sternum, superior aspect of the first costal cartilage

structures that contribute to stability in the AC and SC joint

ligaments

SC joint motion

elevation/depression, protraction/retraction, upward/downward rotation

function of AC joint

maintaining articulation of the clavicle with the scapula

functions of the ST joint

-amplifies the motion of the GH joint

-shock absorber to protect the shoulder

ST joint motions

elevation/depression, protraction/retraction, upward/downward rotation

articulations of the ST joint

no bony articulations, held in place by muscular tension

how is the shoulder is an example of dynamic stability?

the surrounding musculature (rotator cuff)

why is the clavicle "S" shaped?

to clear the ribs and provides more rotation

scapulohumeral rhythm

-smooth, integrated, and coordinated movement of the humerus, scapula, clavicle, thorax

-scapula rotates upward, GH joint flexes or abducts

what are the purposes of normal scapulohumeral rhythm?

-maintain glenoid fossa in optimal position for articulation with head of humerus

-maintain appropriate length-tension ratios of the GH and SH muscles

-maintain full, pain-free shoulder complex ROM

what is the ratio of GH to ST joint movement?

2:1

muscles of the scapula

serratus anterior, upper trapezius, middle trapezius, lower trapezius, rhomboids, pec minor, levator scapula

action of serratus anterior

abd of scapula

action of upper trapezius

elevation of scapula and SC joint

action of middle trapezius

add of scapula

action of lower trapezius

depression of scapula

action of rhomboids

elevation and add of scapula

action of pec minor

depression and upward tilt

action of levator scapula

elevation and downward rotation

force couple of scapula

upper trapezius, lower trapezius, serratus anterior

motion the force couple of scapula produces

upward rotation

irregular motions of ST joint

upward tilt and lateral tilt (winging)

what is upward tilt?

inferior angle of scapula moves away from thorax

what is lateral tilt (winging)?

medial border of scapula moves away from thorax

articulations of the GH joint

humeral head and glenoid cavity of scapula

structures that contribute to the stability of the GH joint

joint capsule, GH ligaments, coracohumeral ligaments, surrounding musculature, labrum

muscles of the shoulder

teres major, coracobrachialis, latissimus dorsi, pec major clavicular and sternal

actions of teres major

extension, add, internal rotation

action of coracobrachialis

flexion

action of latissimus dorsi

extension, add, internal rotation

actions of pec major clavicular

flexion, internal rotation, horizontal add

actions of pec major sternal

add, internal rotation, horizontal add

muscles of the rotator cuff (SITS)

supraspinatus, infraspinatus, teres major, subscapularis

action of supraspinatus

abd

action of infraspinatus

external rotation

action of teres major

external rotation

action of subscapularis

internal rotation

how does the rotator cuff contribute to dynamic stability

all of the rotator muscles stabilize the head of humerus and glenoid fossa during shoulder motion

functions of labrum

-increases depth of fossa

-promotes joint stability

-increases articular contact area

-decreases stress on glenoid fossa

GH joint capsule

Large, loose bundle of tissue that is 2x the surface area of the humerus

closed packed position of the GH joint

full GH external rotation with abd to 90 degrees

open packed position of the GH joint

30 degrees scapation

articulations of the humeroradial joint

capitulum of humerus and head of radius

articulations of the proximal radioulnar joint

head of radius and radial notch of ulna

articulations of the distal radioulnar joint

head of ulna and ulnar notch of radius

articulations of the radiocarpal joint

distal radius with the proximal row of carpals (scaphoid and lunate) and distal ulna with the fibrocartilaginous disc

stabilizing ligaments of elbow

medial collateral ligament (MCL) and lateral collateral ligament (LCL)

function of MCL

resist valgus forces applied to the elbow

function of LCL

resists varus forces applied to the elbow

ligament supporting the proximal radioulnar joint

annular ligament

function of the annular ligament

stabilizes the head of the radius against the ulna

what is the carrying angle?

in anatomical position, the forearm is slightly abd (10-15 degrees) relative to the humerus