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Acceleration Phase

Posted: Tue Mar 30, 2004 11:41 am
by jetlag
I know I always ask very specific questions but here I go again.

In the 60's the sprinters used a stay low approach to sprinting the 100 and 200. There were some fast times, but not like current sprinters are running on a world level. By the 80's, Charlie Francis had implemented a very different start that incorporated a starting style which ejected the sprinter, namely Ben Johnson and Desai Williams, out at about a 45 degree angle and they would be up and running in almost full form by the 3rd step.

In 1996, another Canadian sprinter, Donovan Bailey who was consistent for almost four years at a high caliber competition level, (flash in the pan), used a start that was very explosive but clearly stayed in a lower running position for a specific number of steps. He used this method throughout the prelim and semi heats and then broke the world record at that time in the '96 Olympics. In the final, he was mediocre out of the blocks and in second to last place at mid point of the race and still won convincingly. He actually stayed in that low acceleration phase longer than anyone else.

Now everyone from Marion Jones, Inger Miller, Maurice Green, Alto Bolden and Tim Montgomery are using the stay low method for 10-15 steps depending on their height and running style. Most of the runners who popularized this method of sprinting are or have been under John Smith who makes good sense of his logic when asked.

Interestingly enough, Marion Jones has now incorporated (at her first meet since having the baby) a method of coming out of the blocks.
Last thing, interestingly enough, Marion Jones, who let go of Charlie Francis after scrutiny, uses Coach Pfaff and has used a start that gives a very explosive but quick push of the front leg and then it follows the lead leg out of the blocks so that it is ready for the second step out of the blocks immediately. She loses no momentum because the initial push is so aggressive it gives good time to recover and get the legs back under her, strikingly similar to Ben Johnson's old start.

What I want to know is, where do you stand on the various starts that are used? Allyson Felix is using the 80's method of starting and acceleration. Her coach was Evelyn Ashford's coach at one time.

Also, when do you use this method? I have a junior high school runner who just ran a 7.7 fully automatic in the 60 but she is up and running erect by the 4th-5th step. She is only about 4 and a half feet tall. She has run as fast as 11.8 in the 100 in her sophomore year. I want to change her start, but I am uncertain if I should do so.

Acceleration Phase

Posted: Tue Mar 30, 2004 9:57 pm
by Mgoblue
Much of the starting technique will be due to the starting/set position. The set position including the block spacing (though I find the two and one method to be a pretty good way to begin - not had much success with the measuring of trochanter lengths, find that it ends up in too much of a bunch start) is largely dictated by the athlete's current strength and power levels.

So often you hear coaches say stay low or drive low, where, in fact, the athlete has nowhere near the necessary strength levels to drive out low while remaining in a straight line and not piked over like you see so many athletes. As Francis and others have pointed out, it is important to allow the trunk or back to raise the head and not the other way around. If the head rises prematurely, the athlete will be upright too soon, the hips will drop down and though they may be moving very well in mid-race (100m) they will fade out from about 60-70 meters out.

I would look for straight lines and complete extension of the body. I think the best coaches design the athlete's set/start position around whatever their strength or lack of current strength will permit and not around what others are doing.

I always felt like one of Marion's problems is that she allowed her shoulders to get too far forward of her hands and not directly over her hands, thus not allowing her to have much tension in the blocks -virtually falling out of the blocks. You can see Francis did this looking at his two athletes in the Seoul final in Ben and Desai Williams. Two athletes coached by the same guy with very different starting techniques, but both great starters despite differences in maximum strength levels.

By the way, specific questions are great, that way people can get right to the heart of the matter.

With regards to Donovan, he was not a bad starter, but he had a very short torso and very long legs that hindered his leverage and somewhat limited his acceleration in the first 5-10 meters or so. As leverage became less of an issue and the longer leg length becomes an advantage, he is able to really move on the field in the '96 games. His leg length, in my opinion, would prevent him from ever becoming a terrific starter though he was not bad.

I would focus on making sure the athlete is in a good set position and keep the legs tensed against the blocks. Many starting problems are due to the athlete typically appearing to be too bunched in the set position and not able to keep a flat back at set. Most athletes will have their feet too close to the line rather than too far, though too far is certainly not ideal either. Hope this helps.

Good stuff

Posted: Wed Mar 31, 2004 6:29 am
by jetlag
Thanks. One question, what is a trochanter length?

Trochanter

Posted: Thu Apr 01, 2004 3:27 pm
by Guest
To measure the trochanter length, x-rays and special tools are required. How does one measure the trochanter? For those questioning the definition of trochanter:

Trochanter: One of the bony prominences toward the near end of the thigh bone (the femur). There are two trochanters:

· The greater trochanter: A powerful protrusion located at the proximal (near) and lateral (outside) part of the shaft of the femur;
· The lesser trochanter: A pyramidal prominence projecting from the proximal (near) and medial (inside) part of the shaft of the femur.

The greater trochanter is also called the major trochanter, the outer trochanter, and the lateral process of the femur. The lesser trochanter is alternatively called the minor trochanter, the inner trochanter and the medial process of the femur.

The trochanters are points at which hip and thigh muscles attach. The greater trochanter gives attachment to a number of muscles (including the gluteus medius and minimus, piriformis, obturator internus and externus, and gemelli muscles) while the lesser trochanter receives the insertion of several muscles (including the psoas major and iliacus [iliopsoas] muscles).

Coach Payan
www.CoachesEducation.com

Acceleration Phase

Posted: Sun Apr 11, 2004 5:08 pm
by Tony Veney
In response to questions about the acceleration phase of the sprint start, we need to focus on not what they do but why they do it. It is important to note that when we examine the great sprinters, all of their coaches work with them long enough to determine their strengths and weaknesses when placed in the blocks. The longer acceleration phase we are seeing today is in an effort to accomplish two things:

1.
To prevent a premature transition to top end speed or a sprint panic. Carl Lewis and Donovan Bailey both were criticized for poor starts, but were both efficient at maximizing their acceleration, transition to top end and speed maintenance phases. To say they were slow starters is deceiving when they run 9.8+!

2.
To make sure that the acceleration is pushed deeper into the race as possible to reduce the later phases and the affect of negative acceleration on the race finish.

The difference between a world-class man and an average sprinter in the first 10-20 meters is visibly clear but the time difference is small. But when the stronger, more powerful, more gifted sprinter reaches max speed the separation is stunning. Acceleration is the springboard to where the medals are won. In springboard diving, you don't get points for how you bounce the board, but how you complete the skill in mid-air and enter the water. But the cleaner and more efficient the bounce is, the better everything else is.

A little girl under 5 feet tall must learn to drive as deep as her body and skill (power) will let her and then she must develop the speed strength to run like a sewing machine to the wire. Warning: If she is a "little girl", make her run like a little girl and not like a big girl. When we emulate a sprinter, know what you are looking at and why they do what they do. I hope this helps.

Tony Veney