ELBOW

100問 • 1年前

問題一覧

The elbow complex serves the ______ by providing mobility for positioning the _____ in space

hand

______ at the elbow complex enhances the hand’s mobility, working in conjunction with stability for skilled movements involving tool

rotation

Elbow joint includes

humeroulnar, humeroradial

Humeroulnar and humeroradial joints classififed as a _______ joint that functions as a ________ joint

compound, modified or loose hinge

Proximal and distal ______ joints work together as one functional unit, producing forearm rotation

radioulnar

Humeroradial and humeroulnar joint degree of freedom

Elbow joint has ___ major ligaments and ___ associated muscles

2, 5

Five associated muscles in elbow jts

3 flexors, 2 extensors

Radioulnar joints have ___ ligaments and ___ associated muscles

6, 4

Muscles associated with radioulnar jts

2 supination, 2 pronation

The elbow joints and distal radioulnar jt share a single joint capsule but form distinct articulations

False

Articulating surfaces of the humerus

trochlea, capitulum, fossae

Located on anterior aspect of distal humerus

trochlea

Forming part of the humerulnar articulation

trochlea

Hourglass shaped and angled medially, lying slightly anterior to the humeral shaft

trochlea

Located on the anterior lateral surface of the distal humerus

capitulum

Forms part of the humeroradial articulation

capitulum

What separates the trochlea and capitulum

capitulotrochlear groove

Located above the trochlea

coronoid fossa

Designed to receive the coronoid process of the ulna at the end of elbow flexion

coronoid fossa

Situated above the capitulum

radial fossa

Designed to receive the head of the radius in elbow flexion

radial fossa

Located on the posterior side of the distal humerus

olecranon fossa

Designed to receive the olecranon process of ulna at the end of the elbow extension

olecranon fossa

The articulating surface at the humeroulnar jt is the

trochlear notch

A deep, semicircular, concave surface

trochlear notch

The articulating surface at the humeroradial jt is the

radial head

Slightly cup-shaped concave surface known as the fovea

radial head

Slightly cup-shaped concave surface

fovea

Occurs as sliding motion of the ulnar trochlear ridge on the humeral trochlear groove

humeroulnar jt

Shallow concave radial head sliding iver the convex capitulum

humeroradial jt

Joint surfaces are slightly incongruent

humeroradial jt

against valgus(outward) forces

MCL

Against varus(inward) forces

LCL

Primary fiber of MCL

anterior fiber

Primary fiber of LCL

lateral radial fibers

Fibers of LCL

lateral radial fibers, lateral ulnar fibers

MCL fibers

anterior, transverse, posterior

The humeroulnar, humeroradial and inferior radioulnar joints are enclosed in a single joint capsule

False

Attaches to the ulna along the coronoid process margin and blends with the annular ligament

distally

Attaches above the coronoid and radial fossae of the humerus

proximally

Continuous with the collateral ligaments

medially, laterally

Located between the capsule and synovial membrane near the olecranon, coronoid and radial fossa

fat pads

Joint capsule of elbow is _____,______,_____ in the anterior and posterior regions

large, loose, weak

Capsule contains folds that expand to allow full elbow motion

true

Lines the coronoid, radial and olecranon fossae as well as the medial trochlear surface and the lower part of the annular ligament

synovial membrane

Plays crucial role in valgus stability at the elbow, preventing the joint from moving too far inward

MCL

MCL: primary stabilizer against valgus stress, especially between 20 to 120 deg of flexion

anterior bundle

MCL: Tightens in a reciprocal manner eith the elbow flexing and extending, and provides crucial restraint at various flexion angles

anterior bundle

MCL: helps limit elbow extension but is less important for valgus stability

posterior bundle

MCL: Ligament connects the medial humeral epicondyle to the coronoid process of the ulna, with a broad insertion that helps distribute stress

posterior bundle

MCL: Injuries often occur during activities with repeated valgus stress, such as pitching in sports

posterior bundle

Important for stabilizing against varus stress and longitudinal distraction

LCL

Crucial for maintaining the stability of the elbow joint during various movements

LCL

Major flexors of the elbow

brachialis, biceps brachii, brachioradialis

Mobility

spurt

Origin far from jt

spurt

Insertion near the jt

spurt

Muscle fibers almost perpendicular to the bony lever where it is inserted

spurt

Moment arm is nice if fibers are almost perpendicular to the bone being pulled

spurt

Rotary effect

spurt

Stability

shunt

Origin near the jt

shunt

Insertion far from jt

shunt

Muscle fibers are parallel to the bony lever where it is inserted

shunt

When it contracts, it pulls the bony lever and results to compression or approximation

shunt

Compression/translatory effect

shunt

Shunt muscle of elbow flexors

brachioradialis

Spurt muscle of elbow flexors

brachialis, biceps brachii

Affected by FA position

brachioradialis, biceps brachii

Unaffected by FA position

brachialis

MMT of brachialis

forearm pronation

MMT of brachioradialis

midprone/neutral/misposition

MMT of biceps brachii

forearm supination

Major extensors of elbow

triceps brachii, anconeus

Strongest head of triceps

lateral head

Prone to active/passive insufficiency head of triceps

long head

Which is active whether resisted/unresisted in the triceps head

short

Triceps brachii: FA position

unaffected

Triceps: Shoulder position

affected

Small muscle that assists in elbow extension and acts as a stabilizer during FA rotation (supination)

anconeus

Everytime the biceps brachii contracts, this muscle simultaneously contracts

anconeus

Provides elbow extension just to counteract the elbow flexion produced by the biceps brachii

anconeus

Flexion and extension is cancelled out by this muscle leaving supination

anconeus

Opposes unwanted action of the agonist

synergist

Forearm supination prime mover

biceps brachii

Synergist of forearm supination

anconeus

Unwanted action of biceps in forearm supination

elbow flexion

Traditionally, the axis for elbow flexion and extension is considered a relatively fixed _______ line that passes through the center of _______ and ________ of the humerus, bisecting the humeral shaft

horizontal, trochlea, capitulum

Purpose of knowing traditional axis of motion of elbow

crucial for designing elbow prostheses

When UE is in the anatomical position, the long axes of the humerus and FA form an acute angle medially at the elbow

carrying angle

The angulation of carrying angle is due to the medial aspect of the trochlea extending more proximally that the lateral aspect. This configuration shifts the medial ulna trochlear notch upward, resulting in a lateral deviation or valgus angulation of the ulna relative to humerus.

Both statements are false

The carrying angle helps in tasks like carrying a bucket without it hitting the lower limb, as it allows the hand to be positioned above thee center of the mass of the weight

True

Carrying angle: no significant difference in carrying angle between males and females

infancy

Carrying angle: femlae children typically have a larger carrying angle compared to male children

childhood

Carrying angle is formed by

axis of humeral shaft, axis of ulna

Lateral angulation at the elbow

carrying angle

Females have larger careying angle

true

Normal values for male carrying angle

5-10 deg

100

Normal values for female carrying angle

10-15 deg

ROM

Kyla Rafols · 71問 · 2年前

ROM