I agree with the over dorsiflexion but not the cause that you attribute it
to. The three Morris horses Karen refered to have much more hill work than
any of those with problems and ride harder in more difficult terrain.>>>
This could mean "better preparation" as a factor in prevention.
>>I subscribe to some of Rooney's concepts on the cause being the foot
periodically not in sync and having to speed up to land properly. This
causes a flipping motion over extending the foot (speed of motion with mass
of foot) and fetlock joint. Then the impact of landing with a dorsiflexed
fetlock. An additional insult also occurs, due to the more rapid motion, of
actual joint erosion caused by the hypervelocity induced in the sonovial
fluid going from one side of the joint to the other. >>
I can see this as a factor, but the real crunch comes when that pastern is
level with the ground or lower and the fetlock bearing surfaces are being
squashed at the edges. This situation often brings in sesamoid problems, too.
Any significant incidence of sesamoiditis?
>>In our experience, up hill travel in the properly conditioned horse will
see the forefoot actually landing in a flexed, toe first, condition, then
the fetlock straightens and with the impulsion of the rear the toe breaks
over on the front foot.>>
I'm not understanding--"flexed, toe first"--that suggests to me that the hoof
is not extended (in-line p1-p2 axis) but flexed at the pastern joint, bent
down, as if about to stumble, when impacting.
>> "Now, it could occur with a poorly conditioned horse that the forefoot
land in an extended condition and in working off the forehand and "pulling"
instead of pushing the fetlock then can become dorsiflexed. ">>>
I'd want an extended foot. In racehorses, where the dosiflexion occurs is
with delayed breakover. This can occur with fatigue or with long, low hoof
angles or toe grabs--anything that elevates the toe, including
>> With my knowledge of the horses considered, the four that underwent
this was not the case as these were well conditioned, competitive horses.
But then I was not there when the damage was precipitated.>>
Be interesting to see the x-rays to see if these chips originated in the same
areas we see--essentially, forward lips of the joint.
>> Bob Morris >>