by Jimson Lee 9 Comments
This guest blog was written by Adarian Barr, Assistant Track Coach, Jump/Hurdles/Multi-events at the University of North Carolina in Pembroke.
He also wrote Shoulder Rotation: The Secret to Longer Stride, Faster Running and
To read Adarian’s past articles, click here.
Lastly, here was my Freelap Friday Five with him.
What is the Drive Phase in Sprinting?
The “Drive phase” is one of the most controversial and abstract concepts in track and field.
If asked to describe what it is, you get a varied of answers. From keep your head down to pushing to both head down and pushing but a concrete description of when the drive phase is actually taking place and for how long is not given.
This is my concrete concept of the drive phase.
In the photo you have a sprinter coming out the blocks. The set position shin angle is 21 degrees measure from the track not the angle of the knee flexion.
The 3rd photo shows the shin angle when the athlete starts to push. Which is 14 degrees. A reduction of 7 degrees.
In the next photo the right leg touches down shin angle is 40 degrees, then goes to 31 degrees as the leg is loaded, then to 27 degrees as he starts to push and then down to 23 degrees as he reaches extension.
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That reduction in shin angle from touchdown to toe off is what I would classify as a drive phase when landing on the toe with knee and hip flexion.
The touch down angle is when the foot has initial contact with the ground
the prior to angle is the reduction in angles as the leg is loaded. The hip move to just behind the knee.
The start of push is describe when the hip is over the knee or slightly in front of the knee.
The above description would give coaches something concrete to look for and try to help the athlete improve upon. It would also allow analysis to classify what is a good drive phase and what isn’t a good drive phase.
The speed at which the reduction takes place is a factor in sprint speed a they would indicator faster horizontal hip speed.
Waiting until the optimal shin angle to push would also factor into sprint speed. As they would give maximum push to the hips in a horizontal direction.
Just pushing or holding the head down should not classify a drive phase!
In setting up shin angles, The more aggressive the shin angle is in the blocks the closer together the foot pads setting should be to prevent the athlete from stumbling. Also the heel recovery should be lower to get the back leg to the front faster to also prevent the athlete from stumbling.
When is the drive phase over? When the shin angle is close to vertical at toe or foot touch down. So a shin angle of 65 plus degrees would be an indication that that part of the sprint phase has ended.
The part of the foot that makes initial contact in relationship to shin angle also matters.
Once the shin angle goes 65 plus degrees than the 5th metatarsal becomes the optimum initial contact point.
REFERENCE:
- Toe means phalanges to MTP joint
- MTP joint is the ball of the foot.
- 5th metatarsal is the outside metatarsal
About the Author
Adarian Barr is the Assistant Track Coach, Jump/Hurdles/Multi-events at the University of North Carolina in Pembroke. He is also Movement Specialist and Track & Field coach with Next Level Athletics and Fitness, as well as the inventor of PALO.
About Jimson Lee
I am a Masters Athlete and Coach currently based in London UK. My other projects include the Bud Winter Foundation, writer for the IAAF New Studies in Athletics Journal (NSA) and a member of the Track & Field Writers of America.
Reader Interactions
Comments
Chip Keeler saysWhen the athlete is still in the blocks, is it only the front angle that must be 40 degrees or is there an optimal angle for both? What officially starts the second phase (17%). Is it the percentage until the back foot leaves the blocks? How does this progress to further parts of the race? Would love to see this progress in a future article/series? Love what you stand for, great site for experienced coaches to young eager coaches who are still in school competing like myself.
Chip KeelerReply
- adarian Barr says
The front leg’s shin is the only angle that I look at. The lower it is the better. The push angle will be when the front leg’s shin angle stop dropping or being reduced. Best way to see this is watch the knee, when the knee stops moving downward that is the push angle. The speed at which you go from the set angle to the push angle is the key to really getting a great push out of the blocks. Also being patience enough to wait until you get to the push angle to fire the glutes.
The next phase of acceleration is when the shin angles are above as little as 55 to 65 degrees when the toe makes initial contact with the ground. At that time maintaining a forward lean is critical to keep producing optimal acceleration . This is about the 4th or 5th step out of the blocks. For some athletes it can be as early as the 3rd step out of the blocks.
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- Lplates says
This is great from a coaches point of view, but what is the best way to teach an athlete to drive out correctly? Shin angles and horizontal hip speed would go straight over most young/Junior athletes heads.
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- adarian Barr says
I start the athletes barefooted to see what the shin angles are and to give them a proprioceptive feel of what it is like to be in that position.
I then have them put on shoe s and then spikes and try to get them to replicate the same angles and timing a when they were barefooted.
The next article will be on drills to do to practice getting optimal push during the drive phase.
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- adarian Barr says
The drive phase which in in dispute is really the initial acceleration phase from the blocks to about the 4th or 5th step from the blocks. It could be as short as the 3rd step from the blocks. Each athlete is different. But the shin angles will tell when one phase begins and one ends. You can give that initial acceleration phase any name you like so that takes away the dispute about a drive phase existing or not.
Why shin angles? The shin angles determine how the body is pushing. Also what part of the foot is loaded will dictate what muscles are being used. You can’t push the same way at 60m with shin angles at 55 degrees as you can with shin angles at 10 degrees,
Being on the toes to the MTP joint will activate the glutes and hamstrings. Being on the ball of the foot and heel will activate the quads.We have been trained over the years to look for triple extension, the problem is both ways will get you triple extension but triple extension doesn’t mean you had an optimal push.
But that is what patience is about waiting until your body is on the optimal position to push. The rear leg knee should be slightly in front of the push leg. The hips should be over the knee, the arm should not have been actively moved in any direction until the other body parts are in their optimal positions.
On a side not, foot position will inhibit joints, knee , ankle and hip which dictates which muscles are fired and in what sequence. ” In my opinion as I don’t have any scientific proof”
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- adarian Barr says
The other issue is this gives you an idea of what should be low for that phase of the race. It also will give an insight into when is your athlete pushing. Just because they move or reacted doesn’t mean they have stated to push. In my hope this will move us past yelling at athletes to stay low and also reduce the amount of time we spend on talking about reaction time. If you ever wonder why a Usain Bolt at his length longer reaction time can’t get away from the blocks as fast as a shorter Tyson gay with a shorter reaction , it is because he pushes first and pushes for a longer duration.
Tyson gay has good extension but poor push mechanics.Reply
- adarian Barr says
Not my words but taken from around the web
“What is the drive phase for a sprinter?The drive phase is from the time where the sprinter comes out of the starting blocks to 20 meters down the track. During this phase the spinter is keeping their head and upper body down.”
“The drive phase in sprinting occurs as you lean forward just after starting out of the blocks. Just as the name suggests, you propel yourself by the forceful driving of the balls of your feet into the ground. ”
“http://www.slideshare.net/AthleticsNI/the-biomechanics-of-sprinting”
“Drive the back leg forward keeping the heel low until the shin is approx 45° to the ground and then drive the foot down (see picture to the right) hitting the ground just behind the body’s centre of mass
Over the next 7-8 strides (approx. 10 metres) the angle of shin of the front leg, before it is driven down, will increase by 6-7°/stride so that by the 7-8 stride the shin is vertical
Over the first 7-8 strides the whole body angle will increase from 45° to approx. 30° degrees – approx. 2°/step” as taken from http://www.brianmac.co.uk/sprints/Reply
- Martin says
good
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- Allen Adamson says
Why do we want the shin angle to decrease from 40 degrees to 17 degrees? This will lower the centre of gravity and increase forward rotation, resulting a higher energy requirement in raising the CoG. See Dan Pffaf’s video on the Canadian web site where he coaches high hips in the set position and keeping the hips up through the drive phase.
In the throws a 40-45 degree angle of release is recommended. Is this not the same for a sprinter projecting his CoG, if we are trying to project the hips as far out as possible at the start so that the first contact step is behind the CoG?
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