by Adarian Barr, Assistant Track Coach, Jump/Hurdles/Multi-events at the University of North Carolina in Pembroke.
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.
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.
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.
- 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.