Thoracic Limb

Question 1

Describe the movement of the dorsal border of the scapula as the limb goes in flexion and extension

Answer 1

Limb moves forward – dorsal border of scapula moves caudoventral and lateral.

Question 2

Know how an upright shoulder affects the elbow and the shock absorbing capacity of the limb

Answer 2

Upright shoulder usually combined with an elbow in more flexion and short upright pasterns. This takes away much of the shock absorption of the front limb and will leave the horse prone to concussive injury. Horse will likely have shorter, choppier gates.

Question 3

Know how pronation or supination affects the movement of the limb in flexion

Answer 3

Slight abduction is associated with flexion

Slight adduction is associated with extension

Question 4

Describe the movement of the carpal bones as the carpus flexes and extends

Answer 4

Flexion – carpal bones move towards palmar

Extension – carpal bones move towards dorsal

Question 5

Know which carpal bone has tendinous connections with both the elbow and the foot

Answer 5

Accessory carpal bone

Question 6

List the nerves of the brachial plexus and the muscles they innervate

Answer 6

1. Suprascapular – C(5) C6-C7
   - Supraspinatus
   - Infraspinatus
2. Subscapular – C6-C7
   - subscapularis
3. Musculocutaneous – C6-C7-C8
   - Coracobrachialis
   - Biceps Brachii
   - Brachialis
4. Axillary C(6) C7-C8
   - Deltoid
   - Teres major
   - Teres minor
5. Radial C7-C8-T1(2)
   - Triceps
   - Anconeus
   - Tensor fascia antebrachia
   - Ulnaris lateralis
   - Lateral digital extensor
   - Common digital extensor
   - Extensor carpi radialis
   - Extensor carpi obliquus
6. Median C8-T1(2)
   - Flexor carpi radialis
   - DDF radial head
   - DDF humeral head
7. Ulnar C8-T1(2)
   - Flexor carpi ulnaris
   - SDF
   - DDF ulnar head
   - DDF humberal head

Question 7

Know the attachments for the teres major and minor and the tensor fascia antebrachii

Answer 7

Teres major – caudal distal scapula to lateral proximal humerus

Teres Minor – caudal scapula to medial proximal humerus

Tensor Fascia antebrachia – caudal border of scapula and tendon of latissimus dorsi to olecranon and deep fascia

Question 8

Know the directions of movement/restrictions: coffin joint

Answer 8

1. Flexion/extension
2. Abduction/adduction
3. Internal/external rotation
4. translation

Question 9

Know the directions of movement/restrictions: pastern

Answer 9

1. Flexion/extension
2. Abduction/adduction
3. Internal/external rotation

Question 10

Know the directions of movement/restrictions: proximal sesamoids

Answer 10

1. Medial/lateral

2. Abduction/adduction

Question 11

Know the directions of movement/restrictions: fetlock

Answer 11

1. Flexion/extension

2. Abduction/adduction

Question 12

Know the directions of movement/restrictions: carpus

Answer 12

1. Flexion/extension

2. Dorsal translation

Question 13

Know the directions of movement/restrictions: carpal bones

Answer 13

Accessory: medial/lateral, dorsal/ventral

Question 14

Know the directions of movement/restrictions: elbow

Answer 14

Abduction/adduction

Question 15

Know the directions of movement/restrictions: shoulder

Answer 15

1. Flexion/extension

2. Abduction/adduction

Question 16

Know the directions of movement/restrictions: scapulothoracic joint

Answer 16

Medial/lateral