Leg Strength and stiffness as ability factors in 100 m sprint running

Expert Discussion Biomechanics and Physiology
1

While at the library this evening searching sprint mechanics material I ran across this study that consist of leg strength and stiffness, the study is by C Bret, A. Rahmani, A.-B. Dufour, J Sports Med Phys Fitness 2002 ;42: pg274-81

The purpose of this study was to determined the importance of leg strength and stiffness relative 100 m sprint races and all the phases of the race.

The study had 19 guys times range from 10.5 to 12.4 over 100 m…

I’m not getting the term “stiffness” can someone please explain this term to me…
I’ll take a guess… are they saying the legs should look stiff during the cycle of the stride? :smiley:

If anyone read this article let me know you think. I also have a few questions about the statistical analysis section on page 277

Thanks in Advance

Kenny Mac~~~

2

I think they are referring to tension in the muscle which will permit elasticity. Not too tense or rigid but enough to obtain a sizeable rebound or reflexive action. This is why, among other possible reasons, many people advocate dynamic but not static(at least not a significant amount) flexibility work before speed sessions or meets. That’s my take on it though I could certainly could be wrong-it would be the second time, just kidding. :wink:

3

Thanks for the clarification…
That makes a lot of sense to me.

I stop doing a lot of stretching before races last fall.

I perform about 20 minutes of stretching after races and workout sessions. I notice a difference in my over power. I do more slow tempo before sprinting…ie 10-15 x 100 on grass @ 70% times under 17 sec (100yds) followed by drills up to 50 m & leg swings and a short circuit for 10 minutes @ 50%

After doing some research on stretching before speed work I found that it takes at least 4 hrs before you muscles recovery from stretching.

That’s my 0.02… :smiley:

Kenny Mac~~

4

Originally posted by Pioneer
I think they are referring to tension in the muscle which will permit elasticity. Not too tense or rigid but enough to obtain a sizeable rebound or reflexive action. This is why, among other possible reasons, many people advocate dynamic but not static(at least not a significant amount) flexibility work before speed sessions or meets. That’s my take on it though I could certainly could be wrong-it would be the second time, just kidding. :wink:

Which muscles are you referring to, i.e. hip area, hamstrings or quads?

Thanks

5

I would guess any muscles which undergo an eccentric loading after touchdown.

6

Well that’s all the muscles in the legs I would say :smiley:

Thanks

7

High muscular stiffness means greater forces is required to deform it or lengthen it. A stiff leg on touchdown will prevent the
COM from deviated downwards and are a result more strain energy is generated.

A good example is a stiff rubber band, if you where to stretch it substantial strain energy would be stored. The problem with a stiff rubber band is that stretching it beyond its elastic limit
will cause a rupture in its material.

The same applies to muscles, you wont a muscle to be stiff so you can rebound off the track but at the same time your at a greater risk off tearing a muscle.