“Great starting speed is dependent on the ability to achieve deep angkes and complete extension from the starting blocks…”(Charlie Francis)
Charlie, is the above the same as having " low shin angles"? Also, is it important to have these low shin angles on contact or at toe off?
Thanks
I’m not sure on that one, as you might have a low shin angle, yet have a much higher angle at the femur if the knee isn’t straight. I’d rather think of full extention and the angle of the whole body.
I think longterm addaptations of sprinting and general strength (and core strength) will help here. Any attempt to get down will cause the athlete to slow down. While I think John Smith’s “Drive Phase” has been a nice addition to the sprinting world by instructing athletes to value the acceleration, I think a lot of confusion of how an athlete rises his or her hips gradually is causing a lot of harm now. The first step will dictate the second step, and the second step will dictate the third. Any attempt to fight the natural elevation and posture from the start will cause the athlete to shift gears at the wrong time and negate the athletes power.
Good points! My acceleration is a disaster though, so anytime anyone talks abuot poor acceleration mechanics I think they’re talking about me. :o Actually, I’m finding it very hard to analyze and accomodate my form because of lack of proper equipment (not a damn camera to the name of anyone I know in athletics here in Argentina).
The reference to full extension makes me realize you are talking about the “toe off” phase of the stride. I am more concerned (confused) about what should be happening on ground contact.
Nine times out of ten on the first and second stride out of the blocks there is an acute tibia angle at ground contact. These angles become more vertical to the ground as the run goes on. What I would like to know is: can the angles on the first and second step be vertical on contact as long as they are BDC, followed by deep push off angles and full extension.
Thanks
bump pump pump
Here’s a sequence of Linford in 88.
I know exactly what you are talking about. I think that the angles have to be acute. I always pay particular attention to step 2, it’s a great visual testing point on the start.
Starting is about pushing, not pulling. Pushing has to be an acute angle.
Even if the straight leg drops under BDC it still means that there is pulling happening and it is going to lead to problems as the race unfolds.
I think what Charlie says about the full extension is important to the tibial angle, but there will still be people that try to pull at the start rather than push. Some people just have a fear of falling that holds over from when they were weaker. Some people try to look up to see where they are going (maybe they are afraid of getting lost?). Some people don’t have a feel for the sensation. There’s lots of reasons for this.
Hills and sleds are great for helping this problem.
Thanks a lot for the reply Dcw, and the pics are appreciated.
Do you think there should be a feeling of a upward push during the first few steps? What should be the sensation (details please)?
Thanks
As a learning tool I think it can be good to ask the athlete how they would push a car. If they try to use a 90 degree tibia angle or greater its going to feel very unnatural not to mention rather painful in the hamstrings.
Putting it into perspective what we are trying to do whether starting or pushing something very heavy is to overcome weight and accelerate an object. We need to use the best angle possible which, in order to achieve this is as horizontal as possible. If there was a wall behind you and you wanted to push a car as powerfully as possible you would place your feet on the wall and push - sort of like a swimmer pushing off a wall, because in this case, the downward force of gravity isn’t a factor.
Of course when coming out of the blocks, downward force is an issue and we can only go as horizontal as our levels of power allow.
I absolutely know that I’m speaking for the board when I say that dcw has a knack for conveying extemely relevant information [and the illustrations to support the info] in an easy-to-digest manner, which makes him a great teacher. I’m not ashamed to admit that I seek out his posts ravenously whenever they appear, because much like reading the posts from the head honcho, I get a little more savvy every time I do. Great teachers are hard to find. Much respect-Johnny
Thanks Johnny. Very nice of you. I just make it up as I go along and sometimes it makes sense. 
At a 45 degree angle the horizontal to vertical ratio is 1:1. Any angles bigger than 45 would have more of a vertical componant. I know of athletes leaving the blocks at 42-45 angles, but does any athlete hit these angles on the 2nd or 3rd step. I am guessing no, therefore, the vertical force has to be equal to or greater than the horizontal force.
I think many athletes try to go as horizontal as possible and it prevent their hips from coming up. Have you ever notice how all those SMTC guy had that “bounce” during early acceleration? It would put them behind early, but they never stayed there.
Thoughts please.
Yes, its a constant shifting.
The role of horizontal force is purely acceleration.
Think of the role of vertical force as defeating friction. Kind of like the air in a hovercraft.
The truly powerful can still produce enough vertical force at such extreme angles, though with each step the horizontal force becomes less and less and is required less and less.
You are right that some athletes try to get too an extreme angle for their strength, but these are precisely the ones that end up with the 90 degree tibial angle (or even worse - an obtuse angle) as they don’t produce enough vertical force and end up having to catch themselves, effectively decelerating with each contact and using up way too much energy in the process.
It’s all a balance. Everything about this event is a balance which makes it so damn difficult!
Those SMTC guys may not have had the vicious gut wrenching power of a David Woodhouse ( ) but they had amazing elastic reactive hovercraft power which allowed them to acclelerate with less “friction”.