Hip Flexion vs Hip Extension

Is there any direct corrleation in terms of speed increase when there is less hip Flexion thereby causing more hip extension in a sprint?

You must have flexed at some point to run at all. The amount of extension that is proper and useful is limited to good shin angles and velocity.

no I understand that you have to flex at some point but my question is can the amount of flexion be purposly limit by one in order to get back to extension quicker?

will your extension be more powerful this way?

besides, you can’t cut and measure and think about things while sprinting…

thoughts?

thats what I was asking, if you cut down on the flexion it has to make the extensions quicker to get into

that means lower knee height and smaller strides.

I guess you can cut down on flexion up to the point where the foot of the recovering leg passes over the opposite leg and no further.

Watch little kids run. Often, especially if they haven’t been coached, they’ll run from the hips with high knee lift and full knee extension (in the other, grounded leg). It’s not naturally a function of training or strength conditioning.

Knee lift is a consequence of the process of delivering force through the leg which is being grounded, applying force down and backwards into the floor. In keeping with Isaac Newtown’s laws of motion, you get an equal and opposite reaction manifested in a hip extension (and usually also a knee lift) which in the best athletes is apparently effortless.

It’s like at least the final part of the knee/thigh elevation is a component of a recovery action. It may also be a symptom of the timing/rhythm mechanism in sprinting. I’m no exercise physiologist but, from observation, the fastest 100m people I have seen have a full rotation/range through the hips. Have I missed the point? kk

quicker maybe, but what’s the point if they are not more powerful and shorter?

and if they are not powerful your knee lift will be lower anyway…

thoughts?

Well put. It’s important to watch kids in action to see how things occur naturally- before some jerk “re-patterns” them. comes under the heading: “Stop telling God what to do!”

Here is a different take on hip flexion. “The stretch reflex acts similarly to loading a ‘Y’ sling shot, or forked sling shot. Before shooting the projectile, it remains poised in the stretched elastic, just as the hip flexors remain stretched before the recovery phase. When the sling shot elastic is released, it pops back into original form, sending away the projectile. Novacheck along with Vaughan claim that sprint efficiency is due in part to the storage and later return of elastic potential energy by the stretch of elastic structures(especially tendons) Furthermore, stretched tendons efficiently return energy upon recoil. The stretch reflex refers mainly to the knee cycling during the recovery phase.
The sling shot release parallels the leg recovery phase: the knee cycles through because the hip flexor pops back into normal position from its stretched position. Therefore, the coming through occurs naturally and does not necessitate an athlete’s conscious effort. Furthermore, conciously lifting the knee high while sprinting inhibits the legs natural timing during the recovery phase. Conciously creating a high knee lift is like stretching back a sling shot with projectile and helping push the projectile with the hand while the elastic is releasing. The action would cause a reduction of elastic force, resulting in slower movement with the sling shot as well as with sprinting” (Tom Tellez)

very interesting, Yes I agree that a abnormally high flex hip is not the way to go but then using this same anaoly of a Y sling if you have less hip flexion you wouldn’t be able to send your projectile(hip ext) great distances