PT3 - The Elbow And Throwing

Question 1

What type of joint is the elbow joint?

Answer 1

• modified hinge/pivot joint

Question 2

What is the function of the elbow?

Answer 2

• stability for wrist action
• allow us to bring hand to face
• fills in the space between reach of shoulder and brining the hand closer
• elbow provides supination/pronation of the wrist
• generates force e.g. striking/throwing => acts as a lever between elbow and shoulder
• creates torque through elbow

Question 3

What is GIRD?

Answer 3

• glenohumeral internal rotation deficit
• humerus has similar torsion during development as femur
• twist in humerus e.g. in baseball throwers this twist has become more exaggerated to an external rotation to increase elasticity for throwing (torque), however, still have the same ROM as non-throwers
• greater torque can lead to insufficiency of ulnar collateral ligament => overload through trauma e.g. tennis players

Question 4

What are the functions of the elbow?

Answer 4

• increase ROM for hand
• humero-ulnar joint flexion + extension
• radio-ulnar joint rotation (pronation + supination)
• large area for muscle attachment => common flexor/common extensor tendons
• interosseous membrane binds ulna + radius
• shock absorption e.g. redirect momentum from catching
• joint surfaces are close packed and congruent

Question 5

What movement loads the lateral elbow?

Answer 5

• supination

Question 6

What is the purpose of the interosseous membrane?

Answer 6

• transferral of forces in open and closed chain movements

Question 7

What happens when the collateral ligaments are lax/insufficient?

Answer 7

• can drive other changes in olecranon fossa => wiggles fossa around

Question 8

What can happen when the radius gets compressed laterally (lateral valgus)?

Answer 8

• radius sits next to humerus and can become compressed
• stressing bony structures of humerus, compression of bone and change in cartilage

Question 9

What structures are involved in maladaption of the elbow?

Answer 9

• bone and ligament distruption
• capacity for accommodation mechanical problems at the shoulder is more limited => knock on effect on hand and wrist function
• internally rotated shoulder posture => increase supination requirement => increased tension/shortening of supinations

Question 10

Which muscles perform pronation in the elbow?

Answer 10

• pronator teres and pronator quadratus

Question 11

What muscles perform supination?

Answer 11

• supination and strong biceps

Question 12

What muscles before both supination and pronation?

Answer 12

• brachioradialis aids both => supination from extreme pronation + supinating from extreme pronation

Question 13

What is a common extensor tendon injury?

Answer 13

• lateral epicondylalgia

Question 14

What is lateral epicondylalgia?

Answer 14

• tennis elbow, although most cases are work associated
• epicondylitis => micro/macro tears @ common extensor tendon due to chronic overuse (inflammatory)
• epicondylosis => no inflammation, dense population of fibroblasts + collagen (degenerative)
• epicondylalgia => theres pain, but we don’t know the cause

Question 15

What is the most common cause of elbow pain?

Answer 15

• lateral epicondylalgia

Question 16

Which muscles are most commonly associated with epicondylosis?

Answer 16

• extensor carpi radial is brevis

Question 17

What is the function of the common extensors?

Answer 17

• provide extension of the wrist and hand
• aid grip
• protect radio-ulna joint from excessive forces by absorption in their musculo-tendinous junctions

Question 18

Why does lateral epicondylalgia commonly affect extensor carpi radialis brevis?

Answer 18

• runs from 2/3rd metacarpals => common extensor tendon + lateral ligament of elbow + inter muscular septum
• ECRB small origin => less capable of dissipating excessive force up arm + intimate relationship with lateral ligament of elbow + annular ligament
• symptoms present in lateral ligament + annular ligament may be due to ECRB