Track Speed and Soundness

[TGJB]

This was written by Jeff Seder of EQB Inc.



Some observations on physics and the new Santa Anita dirt track  --  
 
 
Physics says force increases as an exponential (actually the square) of velocity [ i.e.,  f = mass*(velocity squared) ].
 
The faster times we\'re seeing at Santa Anita now, mean more multiples of the force (see physics summary below).  
 
Could this possibly mean it will lead to more injuries?
 
The new 7 furlong record the other day at Santa Anita was 1:19 and change.
 
According to the Thoroughbred Times Racing Almanac (master racing journalist Don Clippinger\'s creation), Spectacular Bid\'s record was 1:20, and the fastest time in 2007 on the new synthetic was 1:20.37. The fastest 7f time on the old dirt track that year was 1:21.11 by Latent Heat.
 
 The average force already on a Thoroughbred racehorse leg at 12 secs per furlong (55 ft per sec) is roughly describable by  force =  mass (1,000 lbs) times velocity (55 ft/sec) squared.  (see Nat\'l Science Foundation studies by Kingsbury in Journal of Biomechanics]
.
[note --  the foreleg retracts - goes backwards, before hitting the ground so the leg velocity is less at impact than the main inertial mass velocity. On the other hand, the faster they go, the more extended they are,  and the less foreleg retraction before impact. The rear legs really don\'t have that sort of retraction.]
 
 Changing from about 1:22 for seven furlongs to 1:19 is a change of  3 seconds overall, or probably at least 1 sec per furlong of velocity somewhere in the race.
 
Go 1 second per furlong faster and the overall velocity is about 5 ft/sec faster. So, for example, if you go 1 sec per furlong faster, instead of a velocity of 55 ft/sec, you\'d have 60 ft per second. Put that into the force equation above. 55 squared is 3,025 times the mass = force.  60 squared is 3,600 times the mass = force.
That is 575 times more units of force possible.
 
Yes, Santa Anita\'s new track could conceivably now be improved in some ways in that it may be \"softer\", or springier, or match the spring constant of a horse\'s leg better than expected, and have fewer inconsistencies in depth and composition and drainage ( future drop hammer tests and ground penetrating radar studies from the Jockey Club\'s track safety initiative will help determine these things).  Furthermore, good athletes there may compensate in the velocity of their foreleg retraction somewhat,
 
but, --  still, --   more potential force in mega units, is still just that.

[covelj70]

Its all anecdotal at this point but unfortunately, some of the injuries that you think would result from a lightening fast track that is producing these fast times are starting to show up.

Obviously, Sydney\'s Candy came out of his last race with an issue and, while he\'s back in training now, it was noted that Twirling Candy came out of his last monster performance with a foot bruise.

Again, this is obviously just anecdotal and not at all rigorous but it\'s ashame to see very good horses come out of races badly, presumably because of the track surface.

Let\'s hope some of the 3 year olds that prep out there don\'t suffer the same fate (especially Asmussen\'s Tapit that looks really nice) so that we can fill the starting gate on the first Saturday in May to make it a competitive race.