Equine Science Hoof care and biomechanics

Question 0

Three layers of external hoof

Answer 0

Periople – thin layer covering wall near coronary band

Stratum medium – bulk of hoof wall
Stratum internum – laminar layer connecting wall to P3

Question 1

External parts of the hoof

Horn tubules

Answer 1

created at coronary band

Cemented together

Question 2

 Action of the external hoof

Answer 2

Expands upon impact with ground
Elasticity depends on water content in hoof
Forces blood out of hoof
Shock absorption

Question 3

Sole

Answer 3

Insensitive
Plate attached to P3, interdigitates with sensitive sole
Concave, allows wall to bear most weight
White line – where sole meets wall
Sensitive
Covers bottom of coffin bone, tissue similar to coronary band Prone to bruising if trimmed too thin

Question 4

Frog

Answer 4

Horny frog – incompletely keratinized tissues
Sensitive frog – nourishes horn-producing cells
Shock absorption

Question 5

Digital Cushion

Interior parts of the hoof

Answer 5

Fibro-fatty, subcutanous tissue

Part of internal frog
Supports P3, shock absorber

Question 6

Laminae

Parts of the hoof internal

Answer 6

Sensitive – attached to P3
Insensitive – attached to hoof wall
60,000 points of attachment, ~8 ft2 per hoof (weight distribution)

Question 7

Biomechanics

Limb cycle

Answer 7

Stance phase
Impact, flexion of fetlock as weight descends
Body moves forward, flexor tendons tighten (point of
maximum stress)
Breakover, toe should dig into ground a little (ease stress)
Effect of toe length, foot shape
Swing phase
Hoof leaves the ground
Extensor muscles pull leg forward
Extends lower leg, repeat cycle

Question 8

Weight-supporting structures

Answer 8

Horn tubules spiral-shaped (spring-like)

Hoof is cone-shaped
Laminar attachment

Question 9

Concussion-reducing structures

Answer 9

Shoulder, pastern slope
Elasticity, movement of hoof wall, ligaments, cushions,
cartilage
Frog’s shape, design, redirects concussion

Question 10

Hoof, non-slip design

Answer 10

Sole is concave
Frog – wedge shape holds foot in place
Toe – sharp, angled, cuts into ground for traction
Wider front hooves (stability)
Narrower hind hooves (maneuverability)
Consistency – rubbery, traction on wet/slick ground

Question 11

Ligaments

Answer 11

General – connect bone to bone
Suspensory ligaments
Between metacarpals and DDFT
Prevents hyperextension of fetlock
Check ligaments
Assist suspensory and form stay apparatus
 Sesamoidean, pastern, navicular ligaments
Aid in supporting joints
Plantar ligament
Outside back of hock

Question 12

Tendons

Answer 12

General – Muscle to bone
No muscle below knee/hock
Longer, prone to problems
Deep digital flexor tendon (DDFT)
Back of leg, attach to P3
Superficial digital flexor tendon
(SDFT)
Back of leg, splits, attach to P2,
P1
Common digital extensor tendon
Front of leg, attach to P1, P2, P3

Question 13

PARTS OF THE LEG BONES

Answer 13

Metacarpal III / Metatarsal III, Cannon bone
Bear weight
 Splint bones
Protect vessels, nerves, etc.
Create larger surface area for knee
Sesamoids
Fulcrum for tendons, ligaments

Question 14

PARTS OF THE LEG BONES

Answer 14

P1, Long pastern bone
Increase flexibility of fetlock joint
Reduce concussion
P2, Short pastern bone
Allow twisting of hoof
P3, Coffin bone
Provide attachment for tendons, etc.
Protect blood vessels, nerves, etc.
Distal sesamoid, Navicular bone
Fulcrum for deep flexor tendon