PHYSIOLOGY

Ground control

The limits on acceleration are commonly

described in terms of horsepower, be it from

internal combustion or accompanied by real

hoofbeats.

But motorbike and drag-racing aficionados

know that too much acceleration can lift front

wheels off the ground, sacrificing control.

Sarah Williams and her colleagues from the

Royal Veterinary College in Hatfield, UK, have

found that quadrupeds face the same problem.

Data from racing greyhounds (pictured,

below) and polo ponies showed that

acceleration limits at high speeds are

predicted by models of muscle power. At

lower speeds, however, animals do not

reach the acceleration theoretically possible

from muscle power. Instead they seem to

be limited by the rate that would cause the

quadruped equivalent of a ‘wheelie’.