The hurdle that goes wrong: what a runner does in the stride after contact

The event as a stride pattern

A hurdles race is run to a fixed number of strides between barriers, which converts the event from free running into a rhythmic pattern. The pattern means the athlete does not choose where to take off, since the take-off point is determined by the strides that preceded it. A runner whose stride length changes slightly will arrive at the barrier from the wrong distance, and the arrival determines everything about the clearance.

This is why hurdling is described as a rhythm event rather than as a series of jumps, and why athletes count rather than judge. Contact with a barrier therefore does structural damage, because it disturbs the pattern rather than merely costing time at that hurdle.

What contact actually does

Striking a hurdle with the lead leg pushes the athlete upward and backwards, extending the flight and delaying the landing. A delayed landing places the foot further from the barrier than the pattern requires, which means the strides to the next hurdle are now too long. Striking with the trail leg has a different effect, rotating the athlete and disturbing the alignment of the hips as the foot returns to the ground.

The trail-leg error is more damaging because it affects balance rather than distance, and balance takes longer to restore than a stride length does. Both errors compound, since a disturbed approach to one barrier makes contact with the next one more likely.

Rebuilding rather than chasing

The instinctive response to losing ground is to run harder, which lengthens the stride and pushes the athlete further from the correct take-off point. The productive response is the opposite, which is to restore the stride pattern even at the cost of a slightly slower stretch between barriers. This requires a decision made in a fraction of a second while the athlete is travelling at close to full speed and is already off balance.

Athletes rehearse it deliberately, practising recovery from a disturbed rhythm rather than only practising clean sequences. Trying to make up the lost distance before the next barrier is the choice that turns one error into two.

The two legs and their separate jobs

The lead leg is driven forward and up with the knee rather than the foot, and it is straightened only as the hip passes over the barrier. An athlete who reaches with the foot lifts the centre of mass higher than necessary, which lengthens the flight and costs time on every barrier. The trail leg is pulled through sideways with the knee high and the foot turned outward, which is the least natural of the movements involved.

Fatigue affects the trail leg first, and a trail leg that drops is the earliest sign that an athlete is in difficulty. The two legs therefore have different failure modes, and identifying which one has gone wrong determines what the athlete works on.

Why the barrier is not jumped

A hurdle is cleared rather than jumped, and the distinction is that the athlete is trying to minimise the disturbance to his running rather than to gain height. Any vertical movement is time spent in the air rather than pushing against the ground, which is why the flight path is kept as flat as the barrier allows. This is also why the barriers are designed to tip forward when struck, since the alternative would make a small error into a fall.

The tolerance changes what a rational athlete does, because clearing the barrier by a comfortable margin costs more than an occasional light contact. The best hurdlers therefore make contact regularly and at the right point, which looks like a mistake and is closer to an optimisation.