arm

Question 1

key points

Answer 1

• the humeroulnar & humeroradial joints function together in elbow flexion – extension.
• the humeroulnar & humeroradial joints gain stability from bony architecture, ligamentous reinforcement and muscle action.
• the proximal RUJ, interosseous membrane & distal RUJ function together in pronation – supination & force transmission.

Question 2

Distal humerus - humeral lateral torsion

Answer 2

The plane of the distal condyles of the humerus is rotated laterally with respect to a line through the centre of the humeral head

Question 3

Distal Humerus - Anterior curve distal end

Answer 3

anterior curvature of its distal portion, which favours a greater flexion versus extension range of movement from the anatomical position.

Question 4

Distal Humerus - Oblique inferomedial joint axis

Answer 4

Medial edge of the trochlea extends farther than the lateral Creates an inferomedial joint axis

Question 5

Valgus

Answer 5

Normal elbow valgus 10-15˚

= lateral deviation of distal segment relative to proximal segment

Question 6

Varus

Answer 6

Medial deviation of distal segment relative to proximal segment

Question 7

2 Compartments of the arm - muscles

Answer 7

anterior & posterior

Question 8

brachial fascia of the arm

Answer 8

medial & lateral intermuscular septa

Question 9

anterior compart.

Answer 9

Coracobrachialis*
biceps brachii – long & short head brachialis
musculocutaneous nerve
- elbow flexion

Question 10

posterior compart.

Answer 10

Triceps brachii– long head, lateral head, medial head
anconeus
radial nerve
- elbow extension
Elbow flexor strength > extensor strength

Question 11

anconeus

Answer 11

anconeus pull capsule out of road so doesn’t get pinched whilst triceps does the work

Question 12

medial and lat. head of triceps brachii

Answer 12

largest force transfer

Question 13

biceps brachii:

Answer 13

Supraglenoid tubercle & coracoid process
> Radial tuberosity
crosses:
•glenohumeral joint •radiohumeral joint •humeroulnar joint •proximal radioulnar joint

Question 14

brachialis

Answer 14

• Humerus > Ulnar tuberosity
crosses:
•humeroulnar joint
always working

Question 15

Brachioradialis:

Answer 15

Lateral supraepicondylar ridge > Distal radius

Recruited with resistance or speed

Question 16

medial epicondyle of humerus

Answer 16

apophysis - secondary ossification centre that doesn’t contribute to increase length of bone