Doing a starting block analysis is one of the most popular topics on the Blog.
When I critique someone’s form, whether it’s out of the starting blocks, or maxV (maximum velocity), I try to find 2 or 3 things they are doing right, 2-3 things what can be corrected or adjusted, and finally HOW TO correct it.
It’s easy to pinpoint what they are doing wrong. If you watch me run, you’ll notice I have quite a few flaws myself. Anybody can be an armchair coach, but coaching someone HOW to correct the flaw is the key. And sometimes you just have to let them run the way they run, like Michael Johnson’s unique upright running form. Or Dwain Chambers “toe-drag”, even if coach Stu McMillan doesn’t teach or endorse it.
Carmelita Jeter Block Start & Drive Phase Analysis
This next section was written and critiqued by Adarian Barr, Assistant Track Coach, Jump/Hurdles/Multi-events at the University of North Carolina in Pembroke.
To read Adarian’s past articles, click here as well as my Freelap Friday Five with him for more background info. Make sure you read “What is the Drive Phase in Sprinting?” Part 1 and Part 2 and Part 3 afterwards once you master your start and starting blocks. Add up a great start, drive phase, maxV, and speed endurance and I can guarantee you a PR in your next 100m.
So let’s start with Carmelita Jeter.
Here is the original video on YouTube.
I didn’t look at the traditional stuff that the sprint coaches or Biomechanist look for which is why I think Jimson asked me to do this series.
Here is my video on Youtube with my voice-over. If you prefer to read and look at a frame by frame analysis, scroll down for the entire critique.
Carmelita Jeter Block Start & Drive Phase Analysis
In this frame here I notice that her right arm or elbow is too far in front of her left leg or knee.
Why is this an issue? The legs will follow the arms, so that arm will stop moving and so will the left leg. She will then have to intentionally lift or drive that knee forward. While she is doing that the right leg will stop pushing, cutting short the duration of her force application period. It will also start a vertical over horizontal movement or more north south than west south. What is really good is how the load has totally shifted to her right leg, which with better arm movement would set her up for a very explosive start and initial high velocity of the blocks.
In this frame here we get to see the short stride length, which is the distance between the heel of the lead leg and the shin of the trail leg. If she increased the duration of her force application period by not lifting or driving the left leg she would actual drag the toe of the right leg as her air time begins.
She shows great patience here by holding her right arm in position or blocks with it to start her air time. The extension of the back leg is a false extension create by the knee extension and not by hip extension. There is a difference in what they do when it comes to force application and what the force is being applied to and the direction of travel the force creates.
Here her left foot has touch down soon after her right leg left the foot pad. Which is short air time and low initial velocity out of the blocks which will effect her top end speed. This is not saying she will have poor top end speed just not optimal.
In this frame her we see that her wrist is loose and from a fascia stand point she is on the back arm line. If the wrist was cocked forward she would be on the front arm line. Which gives and elastic response as oppose to having to use energy to swing the arm forward. The next is the compact body position is really good. Notice how she has flexion at the knee, hip and the foot. If the wrist was cocked forward and she drove through the shoulder, this leg is set to really push her forward as the glutes. This would increase her air time and her velocity.
But wrist action is causing her to spend too much time in a support position instead of a force application period.
Side note here, notice that her right hand is now making a fist. Her left hand stays open with fingers spread through the whole race.
In this photo you now she she has a an open hand again, looking at the right hand. Also her arm is still too far ahead of her leg movement, She is not in-sync yet with her arm and leg movement. The sooner you get in sync the sooner can open up and run .
Here we see again a short stride length and a short air time due to the unsync movement between her arms and legs. One thing that she does well is swinging her arms forward instead of down and back.
This frame shows the start of her air time. The left leg is ready to touch down again shortly after the right leg leaves the ground.
This frame shows the lack of push coming from her legs. Her rear leg is almost coming off the ground and she still has flexion at the knee and hip. I do like the forward aggressive torso lean that she is maintaining. She needs to let her hands travel higher, this will increase her stride length and her air time as the rear leg will increase the force application duration.
Here is a good example of being vertical, You see that her foot is off the ground as she begins her air time or flight time, he stride length phase has just ended and the gap or distance between the heel of the front leg and rear leg is small. Her shin is pushing vertical instead of pushing her horizontal. That aggressive torso angle and her shin angle are matched up which is a good thing.
In this frame here after 10m you see she is still maintaining an aggressive torso lean. Her arms and legs have sync up and now she is getting good flight time. Her stride length cold still be longer if her hands rose higher when coming forward.
If you agree or disagree with me, please comment below. Healthy discussion is great.
Leave a Reply