Lecture 15: Posture and Passive Stay Apparatus in Horses

Question 1

Importance of passive stay apparatus

Answer 1

Reduce muscular support while standing for long periods

Question 2

How does passive stay apparatus reduce muscular effort while standing (general)

Answer 2

Combine force of gravity with properties of skeleton, tendons and ligaments to maintain balance

Question 3

3 components of passive stay apparatus

Answer 3

Suspensory apparatus
Check apparatus
Stay apparatus

Question 4

2 components/ligaments of suspensory apparatus

Answer 4

Interosseus ligament
Distal sesamoidean ligaments

Question 5

Suspensory ligament: definition, origin, insertion

Answer 5

Tendinous interosseus muscle
O- palmar carpal ligament and metacarpal III
I - proximal sesamoid bones, extensor digit or um

Question 6

Distal sesamoidean ligaments

Answer 6

Extend suspensory apparatus to pattern

Question 7

Function of suspensory apparatus

Answer 7

Prevent hyper extension of manus and pes
Prevent overextension of MCP/fetlock, PIP/pattern and DIP/coffin without muscular action

Question 8

How does suspensory apparatus work

Answer 8

Pull of apparatus —> coffin/DIP flexes —> palmar surface of distal phalanx and hoof moved into caudal position (rather than being flat) —> extensor branch of interosseus inserts on middle and distal phalanx —> coffin joint extended back to proper position without extension of fetlock and pastern

Question 9

2 components of check apparatus

Answer 9

Flexor digitorum profundus
Flexor digitorum superficialis