1. Force Output/Projection
Factors:
Start position ex: Track block stance, Football stance, Baseball stealing a baseTransition Start
ex: Soccer-breaking on the ball, Lacrosse turnover getting upfield
The optimal body angle is 45 degrees to the ground at the initial start. This relates more to a traditional start position. The stronger the athlete, the lower he/she can get and hold that angle. In the case of a transitional acceleration, the athlete will not have the time to get to a 45-degree angle. They are already moving, so the low angle is less important as compared to the application of force in the proper direction. Horizontal Force output turning into vertical Propulsive forces. This will help with the projecting the hips up and out. Check Alex Morgans Transitional Acceleration.
2. Stride Rate/Rhythm
The Cadence/ Stride Rate will increase now that the athlete has overcome inertia. The Athlete will produce a Piston-like action during this phase. In Pure Acceleration the Horizontal Force output to aid in the Rise (Transition) to Top speed. The Horizontal Forces will transition into more Vertical Forces over time, typically between 15-30 yards.
3. Drive Taller/Rise
One of the misconceptions of acceleration mechanics is the idea that the body is at a 45-degree angle throughout the acceleration phase. Strides 1-3 will adhere to the 45-degree angle or even lower (depending on the ability of the athlete) The stride length increase as does the hips rising taller throughout each stride. The transition from horizontal force application to the Vertical force application will increase the rise of the hip, thus the Rise of the hips/ body. The Transition from pure acceleration to Top Speed is vital in maintaining the speed that has been built up in the 1st 10-15meters/yards.