Some Elements of Structure and Function Flashcards
In the cold how does horses structure influence their ability to cope?
-minimize heat loss
-warm air entering the lungs
In the heat how does horses structure influence their ability to cope?
-maximize heat loss
-humidify air entering the lungs
More surface area/mass means:
more heat loss
Large horses dissipate heat ________ ________ than smaller/skinnier horses:
more poorly
Internal air conditioning
horses have a long nasal passage and trachea so the air has time to warm before it gets down into the lungs
Why do we want the “ideal” structure for horses legs?
landing and pushing forces are distributed equally through the whole leg and the limb swings forward and back
“Ideal” leg structure
limbs should be parallel and a line should be perpendicular to the ground (through the entire leg)
Base narrow
legs are more narrow together
-more forces on the outside
Base wide
legs are wider apart
-more forces on the inside
Toed out/splay footed
toes are facing out
Toed in/pigeon toed
toes are facing in
In at the knee/knock-kneed/carpus valgus
knees are more in towards the midline
Carpus /bow legged
knees are more out away from the midline
Cow-hocked
hocks are pointed in towards each other
-puts more stress on the hocks
Horses that toe in often:
paddle out (wing out)
Horses that toe out often:
wing in (more potential for the limbs to hit each other)
Defect in movement:
-can contribute to wasted motion
-can predispose to limb interference
-often become more exaggerated at speed or with fatigue
Misalignment:
-reduces even force distribution
-affects limb flight
Angular limb defects:
-carpus valgus
-cow hocks
-carpus varus
Forelimb stride characteristics:
-length of stride (ability to reach forward)
-arc of hoof flight (close or away from the ground)
The structure of the shoulder and lower limb affects:
the force distribution of the forelegs
The fetlock and pastern do what?
absorb concussion
What happens with an upright pastern?
it absorbs less concussion and forces are transferred to other structures
The structure of the pelvis, femur, and lower leg affects:
the stride characteristics of the rear legs
Hind limb stride characteristics:
-engagement and power of the hind quarter (ability to reach under and support the body during push off and turning)
Speed =
stride length x stride rate
What characteristics of structure can increase speed?
-long legs
-long period of suspension
What characteristics of structure effect efficiency?
-less energy used if low to the ground
-light legs (fewer bones, heavy bones are close to the body, major muscles are close to the body or smaller)
-gaits
-upper arm to lower leg conservation of momentum
-pendulum motion recycles energy
What characteristics of structure effect strength?
-bone histology (fibers are parallel)
-enlarged bones (ie: coffin bone)
-fused bones
-tongue and groove support structure of joints
-limited rotation of joints
-straight column of bone
