Kinesiology Exam 3 (Elbow + Radioulnar Joints)

What bones make up the elbow

• distal end of humerus

• ulna (larger proximally)

• radius (larger distally)

the lateral humeral epicondyle is on what bone

humerus

the medial humeral epicondyle is on what bone

humerus

the medial condyloid ridge is on what bone

humerus

olecranon process

ulna

coranoid process

ulna

radial tuberosity is on what bone

radius

the humeroulnar joint (elbow) is what type of joint and what motions are permitted

ginglymus (hinge)

only allows for flexion and extension

the radiohumeral joint is what type of joint

condyloid

there is more bony contact in full extension which means there is ____ motion in the ____ plane

minimal to no motion in the frontal plane

when the elbow reaches full extension, there is increased joint stability because of what

the olecranon process received by the olecranon fossa

as the elbow flexes 20 degrees or more, the ____ _______ is unlocked which allows for more side to side laxity

bony stability

elbow stability in frontal plane during flexion is dependent on the ______ ligaments

collateral

radial and ulnar collateral ligaments

the ulnar collateral ligament provides _____ structure to prevent elbow from _____ when stressed

medial

abducting

the UCL is crucial in ______ (sport) for medial elbow stability

baseball pitching

what surgery is done to surgically reconstruct the UCL using a tendon graft from palmaris longus tendon

Tommy John surgery

_____ force stresses medial ligaments (valgus or varus)

valgus

the radial collateral ligament provides ___ stability

lateral

what is the carrying angle

common for forearm to deviate laterally from arm 5 to 15 degrees

• dominant limb greater than non dominant

• females usually have a higher carrying angle than men

A normal carrying angle is a _____ projection and is usually between ____ degrees

lateral

5-15

An excessive cubitus valgus carrying angle has a degree of ____ or more

30 degrees

A cubitus varus carrying angle has a degree of ____ or less

-5 degrees

Gun stock deformity is a _____ projection of ____ degrees or less

medial

-15 degrees

how many degrees of freedom at the elbow and what motions occur to what degree

1

flexion (150 degrees)

extension (0 degrees)

*hyperextension 10 degrees or less

the radioulnar joint is what type of joint

trochoid or pivot-type

the ____ head rotates around the proximal ____

radial, ulna

the ____ ligament maintains radial head in its joint

annular

what holds the radius and ulna together

interosseus membrane (sydesmosis)

what motion occurs at the radioulnar joint (1 pair)

supination and pronation

what plane of motion do pronation and supination occur in

transverse plane

what are the 3 main elbow flexors

• biceps brachii

• brachialis

• brachioradialis

what are the 2 elbow extensors

• triceps brachii

• anconeus

the short head of the biceps brachii originates ____ and inserts ____

O: coracoid process/glenoid fossa

I: radial tuberosity

what 3 functions does the short head of the biceps brachii do

• elbow flexion

• supination

• weak GH flexion

the long head of the biceps brachii originates ____ and inserts ____

O: supraglenoid tuberosity

I: radial tuberosity

what 3 motions does the long head of the biceps brachii permit

• radioulnar supination

• elbow flexion

• weak GH flexion

the biceps brachii is bi or mono articulate

biarticulate

the brachialis originates _____ and inserts ____

O: humerus

I: coronoid process and ulnar tuberosity

what motion does the brachialis muscle do

elbow flexion

the brachioradialis is known as the ______ muscle

beer drinking muscle

the brachioradialis originates ____ and inserts____

O: supracondylar ridge of humerus

I: styloid process of radius

what 2 motions does the brachioradialis do

• elbow flexion

• gets radioulnar joint back to neutral (from either supination or pronation)

the pronator teres originates on _____ and inserts _____

O: medial condyloid ridge of humerus and ulna (2 heads)

I: lateral radius

what major function does the pronator teres have

pronation

what head of the triceps brachii is biarticulate

long head

all 3 heads of the triceps brachii do what function

elbow extension

the anconeus originates on ___ and inserts on _____

O: lateral condyle of humerus

I: olecranon process of ulna

the anconeus does what

elbow extension

what are the 3 radioulnar pronators

• pronator teres

• pronator quadratus

• brachioradialis

what are the 3 radioulnar supinators

• biceps brachii

• supinator

• brachioradials

the pronator quadratus originates ___ and inserts ____

O: distal anterior ulna

I: distal anterior radius

what function does pronator quadratus serve

pronation

the supinator originates ____ and inserts ____

O: lateral condyloid ridge of humerus + ulna

I: proximal radius

supinator muscle does what motion

supination

forearm flexors and pronators originate on the

medial epicondyle

forearm extensors and supinators originate on the

lateral epicondyle

the common flexor tendon is located on the _____ side, acts as a _____ stabilizer of the elbow and resists _____ force

_____ humeral epicondyle

• medial

• dynamic

• valgus

medial

the common extensor tendon is located on the _____ side, acts as a _____ stabilizer of the elbow and resists ____ force

_____ humeral epicondyle

• lateral

• dynamic

• varus

lateral

which is more common: lateral epicondylitis or medial?

lateral

what is tennis elbow

• lateral epicondylitis

• common problem involving the extensor digitorum muscle near its origin

• associated with gripping and lifting exercises

what is golfers elbow

• less common than tennis elbow

• associated with medial wrist flexor and pronator group

• over pronation and flexion

both lateral and medial epicondylitis involve muscles that cross the ____ but act on the ____

• elbow

• wrist/hand

what muscles are found on the anterior medial side of elbow/forearm and anterior at hand (3)

• flexor carpi radialis

• flexor carpi ulnaris

• palmaris longus

what muscles are found posterior laterally at elbow/forearm and posterior at hand (3)

• extensor carpi radialis longus

• extensor carpi radialis brevis

• extensor carpi ulnaris

how many biarticulate muscles are there in the elbow/forearm

10