Tyler-
I just finished a quantitative (not just observational / qualitative) biomechanical analysis on Smoot’s sprint mechanics. I’d like to address some of your comments based on what I found and observed.
[i]Originally posted by Tylerkelly[/i]
The first thing I noticed is your lack of leaning into the run. Starting from a 0 velocity, you should be leaning more nito the direction of travel to facilitate more force exerted in acceleration.
While much of what you have said is true, I actually don’t think he should be leaning more into the run. His initial body lean is more than sufficient for a standing start (~50 degrees). Sprinters in blocks or athletes starting from a crouched position will have greater body leans due to their initial starting position which puts their feet behind them and their COM low right from the start. A standing (and side-ways for baseball) start doesn’t permit this type of body lean. Smoot could “fake” a bigger body lean by bending more at the hips but this wouldn’t be advantageous.
Also, I think you could use more arm movement…it doesn’t look complete to me. It looks to me as if your arms aren’t being used to increase speed, though that is an indiviudal limit that is dependent upon your flexibility and strength. (Look at elite sprinters starting..their arms are almost completely straight when they reach the apex of swing. Possibly to counter force exerted by oppostite leg?)
Smoot does have some arm swing issues but I was actually not concerned about what you mentioned. The arm swing you describe in elite level sprinters is due to the fact that their push angles are very low at the start of the acceleration and the leg movements have to be very large with complete extension. The arm movements must then be of equal magnitude to counterbalance the leg action. Because Smoot doesn’t have (or need) the low push angles (because he’s starting from a standing position) and because his higher starting position doesn’t make greater magnitude leg movements beneficial, his arm swing won’t need to open up as much behind him.
Looking over the video some more, it seems that your first 1-2 strides seem to have the right body angle (one that delivers force directly along body). You seem to lose this position shortly thereafter. You cease utilization of the “drive phase” of the run and transisition into a MaxV style much too early in my opinion. I woudl recomend extending the drive phase as well as an emphasis on complete and total movement of the arms (it looks rushed) in order to increase your speed.
I found that this is actually an illusion. Smoot’s initial body push off angle is very good but it actually doesn’t progress at all (as you suggest). In fact, his push off angle (the line of force application from his ankle through the long axis of his body at the moment of pushoff) for his first 7 strides actually doesn’t increase to any significant degree. What you’re seeing is that his trunk position (the angle formed by his trunk and the horizontal plane of the ground) in his initial steps is too low because he is bent a little too much at the hips. This is caused by him tucking his chin to his chest for the first 3 steps. As a result, when he picks his head up at around step 4, it causes his hips to tuck under him and give the illlusion of him standing up when in fact his push angle hasn’t changed at all. In fact, as I mentioned earlier, seven strides into the acceleration he is not much closer to upright running posture than his was after the first step. Smoot’s forward lean is actually too great at maxV. He has a forward trunk position which is on average 20 degrees off perpendicular to the ground and also exhibits excessive backside mechanics. This makes it difficult for Smoot to apply vertical forces to the ground (vertical force application is associated with higher top end running speeds). I’ve got the quantitative data to back this up but this picture might show it even better. The red line indicates Smoot’s push off body angle and the blue line indicates a more optimal progression of body angles. Also note the chin-tuck and subsequent hip alignment (pictures 1-3) that I discussed earlier.
