Equine Conformation and Biomechanics Midterm

determine soundness, longevity in a career, athletic ability

Why do we evaluate conformation?

Balance, structural correctness, muscling, breed/sex character, quality

What 5 things do we evaluate when looking at a horse’s conformation?

balance

the overall symmetry, blending of parts together

-results from correct skeletal structure

True

true/false: a horse should divide equally into thirds

high

a horse’s neck should be long and ____ tying

long

the horse should have a ____ hip

potential soundness problems

evaluating structural correctness can give insight into _________

65%

what percentage of a horse’s weight is on its front legs at rest

-may be more when the horse is in motion

front leg

this leg is constructed for a larger supportive role

hind leg

this leg is constructed for a more propulsive role

scapula

the ____ generally moves in one plane only

True

true/false : there is no bony connection between the front leg and the axial body

balance

a longer shoulder contributes to greater _____

(though shoulder angle contributes more than length)

dressage and showjumping

a long shoulder is found in both elite ___ and ____ horses

knee action

in general, a steeper angle of the should results in more ________

flatter stride

a flatter angle of the shoulder contributes to a _______

slope of shoulder, stride length

there is a positive correlation between _____ and ____

(quality of gaits)

concussive

this kind of damage is associated with a more upright shoulder angle

-along with synovitis in knee and fetlock joints

humerus

this bone facilitates lateral movement

scope and stability

a longer humerus contributes to more of this

choppy

a horse with a short humerus will have a ____ stride

freedom of shoulder

comes primarily from increased flexion of elbow and carpus

flatter

a flatter angled humerus will cause a ____ stride

higher

a steeper angled humerus will lead to a ____ ability to raise knees

90

ideally, the angle between the scapula and the humerus should be ___ degrees

-will be greater in jumpers and high-stepping horses

large, square, flat

the carpus should appear ____, ___ and ____ from the front

center

the cannon should exit directly out of the _____ of the knee

short

cannons should be ___ in length

same

cannons should be the ____ circumference at the top as the bottom

shock absorption

a longer pastern allows for more _____ and elastic rebound of the limb

ringbone, arthritis

too long of a pastern can break down and predispose the horse to ______ or ______ of the pastern and coffin joints

shock absorbing

a short, upright pastern loses its ______ abilities and is more prone to concussive injuries

shoulder and pastern

the angle of the pastern should be similar to the angle of the ____ and_____

broken-back hoof-pastern axis

term for a long toe, low heel

-often extensive toe length

-predisposes horse to

• sole bruises

• contracted heels

• ligament strains

need to shorten toe and/or support the heel

broken-forward hoof-pastern axis

term for a short toe, long heel

-predisposes horse to

• sesamoid injuries

• coffin joint arthritis

• suspensory ligament strains

-club foot (usually asymmetric)

need to adjust dorsal hoof angle to match the pastern and lower the heel

straight pastern

what is wrong with B

too long pastern

what is wrong with C

calf kneed

what is wrong with D

buck kneed (over at the knee)

What is wrong with E

tied in at the knee

What is wrong with F

base narrow

horses that are _____ will

• lack adequate base of support

• will have difficulty balancing when turning

  • will interfere

wing-in

horses that are toed out will _____ when moving

paddle

horses that are toed in will ____ when moving

rope walk

horses that are base narrow will _____ when moving

carpal

knock-kneed horses will have increased _____ stress

hindquarters

this is the engine for the rest of the body

hindlimbs

conformation of the _____ determines potential for speed, agility, power, stopping ability, and collection

less

hind limbs are ___ prone to lameness than the front limbs

positively

a longer pelvis is ____ corelated with stride length and jumping ability

better

a longer hip contributes to _____ balance

false

true/false : pelvic and croup angle are the same

flatter

a _____ angled pelvis allows the horse to push behind, but hard to step forward under their body

-often seen with a high set tail

femur

this bone should be long and forwardly-sloping

-allows the horse to balance and carry more weight on its hindlimbs

-places stifle under point of hip

long

a ____ femur results in lower stifle and deeper-tying, stronger muscling

-also gives lower hocks and more power

positive

there is a ____ correlation between pelvic and femur length and the length of the stride

hocks

the ____ are one of the most complex and hardest worked joints in the body

-propulsion, turning, shock dissipation

friction/strain

large, well-conformed hocks have less _____ than small, narrow, poorly-conformed hocks

small angle

HOCK: a _____ angle has an increased risk of lameness and back pain

large angle

HOCK: a ____ angle has an increased risk of lameness and concussive damage

Sickle-hocked

What is wrong with C

Post-legged

what is wrong with D

camped under

what is wrong with E

cow hocks

hocks point towards each other, with cannons and fetlocks deviating to the outside

type

certain physiological characteristics can distinguish between breeds or between sexes

proportional to body, broad forehead, large eye set on corners of head, refined, small muzzle, large nostrils

what are 6 things to look for on a horse’s head?

roman nose, large ears, pig eyes, small nostrils, overshot or undershot jaw

what are 6 head faults?

dished profile

a dish below the eyes that is often associated with slightly bulging forehead

-seen in horses with arabian descent

roman nose

when the nose of a horse “bumps” outwards

-associated with cold-blooded breeding

-may have advantage in cold climates

pig eye

small eye that is associated with coarse features

-may be associated with a smaller field of vision

-advantages in cold climates

carcinoma

the white skin around a blue eye can predispose the horse to ____

-reduce their exposure to UV

narrow head

a lack of width between the eyes

-may be narrow in the jaw

-any restriction to air intake can limit performance ability

overbite

top of mouth is over the jaw

-parrot mouth

underbite

bottom of jaw is over the top of mouth

-sow/monkey mouth

A-O joint

this spinal joint allows for flexion at the poll

C-T joint

this spinal joint has a relative location that can influence how well a horse can shift its center of gravity

L-S joint

when this spinal joint is flexed, the hindlimb comes under the body; lateral flexion

S-I joint

this spinal joint aids in shock absorption, transfers forces from hindlimb to vertebral column

1/3

the neck should be about ____ the body length

ewe neck

the widest part of the neck is at the bottom

-hypertrophy of underside of the neck

-associated with

• low base of the neck

• straight shoulder

• stargazing

• horse that evades rider

  • low back/back pain

fallen crest

this occurs when fat deposits accumulate above the nuchal ligament

-may get top heavy and fall

-horse may lose weight, but neck fat dissipates slower

-often associated with obesity/equine metabolic syndrome

knife neck

a long, skinny neck with poor muscle

-horizontally set onto the shoulder

-can be seen with low body condition

mutton withers

low, flat withers

-may be associated with wide backs and downhill conformation

-can cause saddle fit issues, difficulty shifting back center of gravity

high withers

serve as lever for muscles of the neck and back. Attachment point for nuchal ligament

-makes it easier for horses to round back, or use head and neck

-exacerbated with low body condition

-saddle fit issues

roach back

kyphosis of the back

-bump on back of horse

-occurs occasionally in young horses that grow rapidly

-sometimes acquired as a result of trauma or chronic pain

sway back

lordosis of the back

-often seen in older horses and those with a long, weak loin

-weakening of ligaments of back can cause sagging over time

-can be congenital

widows peak

horse appears to have a hollow area between lumbar span and tuber sacral

-rough coupling can be more aesthetically displeasing rather than functionally significant

-may be associated with weak, poorly muscled loin or mild roach back

hunters bump

visible bump at the high point of croup due to SI strain or injury

-dislocation or partial dislocation of SI joint

-sometimes caused by tearing of associated ligaments

wry tail

tail carried to one side

-typically does not affect health or usefulness

stallions vs. geldings

-shorter

-shorter ear

-neck crest

-more muscle

mares vs. males

-broody facial features

-longer ears

-longer body length

bowed tendon

usually a tearing of tendon fibers of SDFT or DDFT

-occasionally due to uneven compression (bandage bow)

-more common in front limbs

-fetlock joint overextends, usually due to fatigue

-conformation risk factors

• long toe/low heel/broken back axis

• long, weak pasterns

• long cannon bones

• tied in behind knee

osselets

traumatic arthritis of the fetlock

-begins as swelling in front of joint, pain

-usually bilateral

-periosteum and articular cartilage turns to bone

-conformation risk factors

• short, upright pasterns

• uneven stresses to the fetlock

ringbone

degenerative arthritis of pastern and/or coffin joint

-one or multiple limbs

-conformation risk factors

• short, upright pasterns (can be deviated)

• big horse, little feet

sidebone

calcification of lateral cartilage in hoof

-some ossification normal with age

-not usually lame

splints

injury to the interosseous ligament or periosteum of the splint bone or cannon

-starts out soft and painful, then becomes bony and no longer painful

-may be caused by trauma or heavy training in young horses

-conformation risk factors

• offset/bench knees

• base narrow

• toe out

bone spavin

arthritis of the lower hock joints due to cartilage compression and/or uneven loading

-usually in older horses

-can cause lameness

-conformation risk factors

• sickle hocks

  • cow hocks

bog spavin

excess fluid/edema in the tibiotarsal joint

-usually not lame

-may be due to underlying OCD or trauma

-conformation risk factors

• straight hocks

• long back/loin

curb

enlargement of plantar ligament due to inflammation or tearing

-may be due to trauma

-conformation risk factors

• sickle hocks

stride cycle

consists of the stance phase and the suspension phase

limb cycle

consists of the stance phase and the swing phase