lecture 8- elbow and wrist function

Question 1

function of the elbow

Answer 1

adjust the over-all function length of the upper limb

Question 2

two interlocking joints

Answer 2

ulnohumeral and radiohumeral

Question 3

the stability of the joint is dependent on the ___________- when the elbow is flexed

Answer 3

collateral ligaments

Question 4

ulnohumeral & radiohumeral ligaments

Answer 4

articular capsule- encloses all three articulations of the elbow region
medial collateral ligament- provides resistance to valgus forces
lateral collateral ligament- provides resistance to various forces

Question 5

valgus

Answer 5

forces that push toward the body

Question 6

varus

Answer 6

forces that push away from the centre of the body

Question 7

normal caring angle

Answer 7

5-10 degrees

Question 8

excessive cubitus valgus

Answer 8

30 degrees

Question 9

cubits varus

Answer 9

-5 degrees

Question 10

gun suck deformity

Answer 10

-15 degrees

Question 11

proximal radioulnar joint

Answer 11

supination and pronation give the upper extremity a mechanical advantage and improve function consider turning a screwdriver

Question 12

interosseous membrane

Answer 12

holds the radius and ulna together. useful in absorbing and transmitting forces received by the hand- especially when weight bearing on the upper extremity

Question 13

muscles acting on the elbow

Answer 13

most muscles that act on and cross the shoulder joint with the exception of supinators and pronators. stability at the shoulder joint has an impact on the function of the elbow joint

Question 14

muscles with an organ at the elbow

Answer 14

common extensor= lateral epicondyle
common flexors= medial epicondyle

Question 15

elbow felxors function

Answer 15

elbow flexor torques produced with the forearm are 20-25% greater than when they are pronated

Question 16

elbow flexor function

Answer 16

combining elbow flexion with shoulder extension naturally increases the torque of biceps. minimizes the rate and amount of shortening required by the long head of the biceps to completely flex the elbow

Question 17

combining shoulder flexion with elbow extension

Answer 17

minimizes the rate and amount of shortening required by the long head of the triceps

Question 18

supinators/ pronators- function

Answer 18

as a group supinators produce 25% greater isometric torque than pronators

Question 19

the stability of the elbow can be altered by:

Answer 19

weak imbalances
-weak muscles
-tight structures
instability
-ligament laxity
-injury
loss of neural control
-impacting dynamic stability

Question 20

ligaments of the elbow

Answer 20

radiohumeral& ulnohumeral ligaments
radioulnar ligaments

Question 21

radiohumeral& ulnohumeral ligaments action

Answer 21

action
articular capsule
medial collateral ligament
lateral collateral ligament

Question 22

radioulnar

Answer 22

annular ligament
interosseous membrane

Question 23

limiting structures
movement
ligaments
muscles

Answer 23

movement- flexion, joint capsule posteriorly soft tissue approximation, triceps brachii
extension, joint capsule anteriorly/ collateral ligaments, brachialis, biceps brachii, brachioradialis
supination- interosseous membrane- pronator teres \ pronator quadratus
pronation- interosseous membrane, supinator, biceps brachii

Question 24

active restraints- muscles

Answer 24

Biceps Brachii
Supinates forearm and flexes the elbow.Short head resists dislocation of the shoulder
Brachialis
Flexes the elbow in all positions.
Brachioradialis
Flexes elbow joint, especially in semi-
pronated position.
Triceps Brachii
Primary extensor of the elbow joint.
Anconeus
Assists triceps in extending the elbow,
stabilizes the elbow joint, may abduct the
ulna during pronation.
Supinator
Supinates forearm
Pronator Teres
Pronates forearm
Pronator Quadratus
Pronates forearm

Question 25

elbow conditions

Answer 25

lateral epicondylitis
elbow instability
dramatic dislocation
excessive strain

Question 26

lateral epicondylitis

Answer 26

tendinopathy
tendons become inflamed (micro tearing or degeneration) usually due to overuse

Question 27

elbow instability

Answer 27

dislocation-
elbow dislocations or subluxations are usually the result of a fall on the outstretched hand (FOOSH)
excessive strain-
Tommy John surgery
reconstruction of the UCL. usually replaced with tendon of the palmaris longus. common amongst pitchers in baseball