← Blog

Should the lead leg be straight over a hurdle?

Nearly, for an instant, but how the leg gets there matters far more than how straight it ends up.

The question usually follows a slow-motion clip of an elite high hurdler, where the lead leg looks almost ruler-straight over the barrier, and then a look at your own athlete clearing it with the knee bent at a right angle. The natural response is to tell the athlete to straighten the leg. What most athletes do with that instruction is kick.

What the good version is doing

A good lead leg is a sequence rather than a position. The knee drives forward and up first, with the foot tucked underneath it. As the knee approaches the height of the barrier, the lower leg unfolds, so the leg opens out across the top of the hurdle. At that moment it is close to straight, often with a little softness left in the knee, and it stays that way very briefly before the whole leg is pulled back down towards the track.

That is what the slow-motion clip actually shows. The straight leg in the still frame is the middle of a movement that began with a bent knee and ends with the foot landing under the hips.

Why kicking it straight makes things worse

An athlete told to straighten the leg tends to swing the whole thing up from the hip with the knee already locked. It can look nearly right in a photograph, and it goes wrong in three ways.

• A straight leg is a long lever, so it is slow to lift and slow to bring back down. The athlete spends longer in the air waiting for it.
• Swinging a long leg up hard tips the upper body back to balance it, which takes away the forward dip over the barrier.
• A leg still reaching out in front as the athlete comes down lands ahead of the body and brakes, so the first stride off the hurdle starts slow.

Why it stays bent instead

A lead leg that never opens usually has a cause, and the cause is rarely that nobody mentioned straightening it.

• Taking off too close. With the barrier right in front of them there is no room for the lower leg to unfold, so the knee comes up and the foot stays tucked.
• Taking off too far away. Now the athlete has to jump to reach the hurdle, and jumps get cleared by tucking.
• Fear of the barrier, which is completely reasonable in a beginner and produces the same tuck.
• Hamstrings that will not allow it. Dipping the trunk and extending the lead leg at the same time is a long stretch down the back of that leg, and an athlete who cannot manage both will give one up, usually the extension.

Barrier height changes the answer as well. The lower the hurdle is compared with the athlete's leg length, the less the leg needs to open to get over it. A tall athlete over intermediate hurdles can clear cleanly with a lead leg that never looks straight, and that is not automatically a fault.

What the Film Room reports, and the catch

The hurdles setting reports lead-leg extension alongside trunk dip over the barrier, how far the hips rise at the hurdle, and overstride between barriers. If no knee in the tracked frames opens past about 155 degrees, it tells you the lead leg is staying folded and names lead-leg snap-downs over a low barrier, which train the lower leg to extend and then pull straight back down.

The catch is worth knowing before you trust a clean result. The number is the widest angle either knee reaches across the frames it tracked, and it does not work out which leg is leading. The takeoff leg straightens as it pushes off the track, so it can supply a wide angle even when the lead leg stayed tucked. That makes a warning trustworthy, because if no knee opened that far the lead leg did not either. A pass is a reason to frame-step to the barrier and look before you believe it.

The other two numbers often say more about this fault. A kicked straight leg tends to arrive with a trunk that stays upright, and the app flags a dip under about 35 degrees. A tucked leg tends to arrive with hips that climb, and the app flags a rise of more than about 22 per cent of body height as jumping the hurdle. Walkover leads at a low height and close-spacing run-throughs are the drills those two findings bring with them.

Film square to the lane from the side, level with the barrier, and far enough back that the takeoff, the clearance and the first stride after it all stay in frame. A camera looking down the lane at an angle can make a bent knee look straighter than it is, or a straight one look bent.

Related