Ch 11 - elbow joint Flashcards
how many axes does synovial joint have?
0-3 axes
when a muscle has contracted (shortened) over all of its joints as far as it can, it becomes?
actively insufficient
when a muscle has lengthened over all of its joints as far as it can, it becomes?
passively insufficient
Distal (fixed); proximal (open)
closed kinetic chain
distal (open); proximal (fixed)
open kinetic chain
3 bones, 3 ligaments, two joints, one capsule
elbow complex
articulation of humerus with ulna and radius
elbow joint
uniaxial hinge joint with flexion and extension
elbow joint
occurs in the sagittal plane around the frontal axis
flexion and extension
145 degrees
flexion
trochlea on humerus articulates with trochlear notch of ulna
humeroulnar articulation
capitulum on humerus articulates with head of radius
humeroradial articulation
this does not occur because olecranon process of ulna fits into olecranon fossa of humerus
hyperextension
if hyperextension occurs, it’s due to _____
laxity of ligaments
head of radius pivots within the radial notch of ulna
proximal radioulnar joint
articulation between radius and ulna
radioulnar joint
involves each bone articulation with the other at both ends of the forearm; uniaxial joint; allows pronation and supination
radioulnar joint
occurs in transverse plane around vertical axis
supination and pronation
90 degrees of motion
supination
80 degrees of motion
pronation
distal end of radius rotates around distal end of ulna
distal radioulnar joint
____ moves around _____
radius; ulna
shorten or lengthen the upper extremity and to place hand in space; allows forearm to move hand closer and farther from body
elbow function
in order to pronate and supinate, the muscle must attach on the _____
radius
when in anatomical positions, the longitudinal axes of humerus and forearm form an angle
carrying angle
5 degrees
carrying angle of men
10-15 degrees
carrying angle of women
occurs because distal end of humerus is ot level- medial side (trochlea) is lower than lateral side (capitulum)
carrying angle
soft end feel because muscle bulk of arm compresses together and limit motion
elbow flexion
bony end feel because olecranon process of ulna moves into olecranon fossa of humerus
elbow extension
firm end feel due to muscle and ligament tension
forearm supination
bony end feel due to connection between radius and ulna
forearm pronation
_____ on _____ relationship
concave on conves
trochlea and capitulum are _____ of humerus
convex
trochlear notch and radial head glide posteriorly
elbow extension
trochlear notch and radial head glide anteriorly
elbow flexion
glides ____ direction as the motion of forearm
same
raised portion on the inferior lip of glenoid fossa that provides attachment of long head of triceps muscle
infraglenoid tubercle of scapula
raised portion on the superior lip of glenoid fossa that provides attachment of biceps muscle
supraglenoid tubercle of scapula
projection on anterior surface that provides attachment for the short head of biceps muscle
coracoid process of scapula
groove that the radial nerve runs through as it spirals around the midhumerus
spiral groove of humerus (distal end)
located on medial side of distal end and articulates with the ulna
trochlea of humerus (distal end)
on lateral side next to trochlea and articulates with head of humerus
capitulum of humerus (distal end)
located on medial side of distal end above trochlea; larger and more prominent; provides attachment for pronator teres muscle
medial epicondyle of humerus (distal end)
located on lateral side of distal end above capitulum; provides attachment for anconeus and supinator muscles
lateral epicondyle of humerus (distal end)
located above the lateral epicondyle and provide attachment for the brachioradialis muscle
lateral supracondylar ridge of humerus (distal end)
located on posterior surface between the medial and lateral epicondyles; articulates with the olecranon process of ulna
olecranon fossa of humerus (distal end)
medial bone of forearm
ulna
located at the proximal end of the ulna on the posterior surface; forms prominent point of elbow; provides attachment for triceps muscle
olecranon process of ulna
semilunar notch; articulates with the trochlea of humerus; makes up anterior surface at proximal end
trochlear notch of ulna
located just below trochlear notch; provides attachment for brachialis muscle
coronoid process of ulna
located at proximal end on lateral side just distal to trochlear notch; articulation point for head of radius
radial notch of ulna
at distal end on posterior medial side
styloid process of ulna
located below the coronoid process; provides attachment for brachialis muscle
ulnar tuberosity of ulna
at distal end on the lateral side; ulnar notch of radius pivots around it during pronation and supination
head of ulna
lateral bone of forearm
radius
proximal end and has a cylindar shape with a depression in superior surface where it articulated with capitulum of humerus
head of radius
located on medial side near proximal end; provides attachment for biceps muscle
radial tuberosity of radius
located on posterior lateral side at distal end; attachment for brachioradialis
styloid process of radius
medial collateral, lateral collateral, annular ligament
ligaments of elbow
triangular; attaches proximally on lateral epicondyle of humerus and distally on annular ligament and lateral side of ulna
lateral collateral ligament
triangular and spans medial side of elbow; attaches to medial epicondyle of humerus and runs obliquely to medial side of coronoid process and olecranon process of ulna
medial collateral ligament
what ligaments provides medial and lateral stability of elbow joint
medial and lateral collateral ligament
attaches anteriorly and posteriorly to radial notch of ulna encompassing head of radius and holding it against the ulna
annular ligament
broad, flat membrane located between radius and ulna that holds the radioulnar articulations together; keeps the two bones from separation and provides more surface area for attachment of forearm and wrist muscles
interosseous membrane
attaches around distal side of humerus and encompasses the trochlea, capitulum, and fossa located above them; attaches around proximal end of ulna under the radial notch and coronoid process and around trochlear notch; attaches around radius just under head
joint capsule
strengthened anteriorly and posteriorly by annular ligaments; collateral ligaments reinforce capsule on joint side
joint capsule
in elbow flexion, the joint capsule is taut on the ____ aspect and slack on the ____ aspect
posterior; anterior
in elbow extension, the joint capsule is taut on the _____ and slack on the ____ aspect
anterior; posterior
between biceps tendon and brachioradialis muscle but not considered to be within fossa
radial nerve
divides into radial (superficial) and ulnar (deeper) arteries near inferior apex of fossa
brachial artery
3 superficial veins (superficial to fossa)
medial cubital, cephalic, basilic
main vertical structures within fossa
biceps tendon, brachial artery, and median nerve (lateral to medial)
if the muscles cross on the anterior aspect of elbow, it performs
elbow flexion
if the muscles cross on the posterior aspect of elbow, it performs
elbow extension
muscles of the elbow and forearm originate on
humerus and sometimes scapula
muscles of the elbow and forearm insert on
radius and ulna
originated medially and cross anterior aspect of joint to insert on radius
pronation
originated posteriorly and cross lateral side of forearm to insert on radius
supination
brachial plexus and innervate all muscles of elbow
terminal nerves
innervates muscle of anterior arm involved in elbow flexion
musculocutaneous nerve
descends arm anteriorly sending branches to pronator muscles
median nerve
travels through axilla and around middle portion of humerus to innervate the posterior surface of arm, forearm, and hand; responsible for elbow extension
radial nerve
“tennis elbow”; common overuse condition that affects the common extensor tendon where it inserts into lateral epicondyle of humerus
lateral epicondylitis
“golfer’s elbow”; inflammation of common flexor tendon that inserts into medial epicondyle
medial epicondylitis
overuse injury of medial epicondyle caused by repetitive throwing motion; places carious stress on elbow causing lateral compression and medial distraction on joint
little league elbow
nursemaid’s elbow; common in children under 5 who experience a sudden strong traction force of arm; force causes radial head to sublux out from under annular ligament
pulled elbow
common in children; caused by falling on outstretched hand; distal end of humerus fractures above condyles
supracondylar fracture
when great deal of force is applied to elbow that is slightly flexed; caused ulna to slide posterior to distal end of humerus
elbow dislocation
which pathologies could potentially damage brachial artery?
supracondylar fracture and elbow dislocation
rare but potentially devastating ichemic necrosis of forearm muscles
Volkmann’s ischemic contracture
pain from hitting funny bone; superficial where it crosses the medial elbow between bony olecranon process and medial epicondyle; creates pain, numbness, and tingling in medial hand and 4th-5th fingers
ulnar nerve compression
brachialis is ____ to biceps
deep