Random Notes

In 1985, renowned orthopedic surgeon Dr. Arthur Pappas conducted some interesting research on 15 professional pitchers.1 Over the course of 147 pitches, he examined with high speed cinematography what he called the three main phases of the pitching delivery: cocking, acceleration, and follow through.

He reported the following data:

1) The Cocking Phase takes 1,500 ms(1.5 sec) and consumes 80% of the pitching cycle.

2) The Acceleration Phase lasts for 50 ms (1/20 sec) and consumes 2% of the pitching cycle.

3) The Follow Through Phase takes 350 ms (.4 sec) and consumes 18% of the pitching cycle.

Adding these times together, the average pitching delivery of a MLB pitcher takes about 2 seconds.

Arm Speed

Pappas further determined that the angular velocity of shoulder internal rotation during the acceleration phase of pitching to be as high as 9,198 degrees/second. The range was from 3,340 to 9,198 deg/sec, with an average of 6,180 deg/sec.

Pappas found peak angular velocities at the elbow to be 6,993 deg/sec with a range of 2,287 to 6,993 and an average of 4,593 deg/sec.

Point A: Beginning of Acceleration Phase, External Rotation

Point B: End of Acceleration Phase, Release Point

The movement of the arm from Point A above to Point B below is considered to be the single fastest movement made by the human body in all of sports.

Contrary to some thinking, the arm is not just “whipped along for the ride” generated by the force & momentum of the rest of the body.

Stored Elastic Energy: 2% vs. 98%

The only time the shoulder pitching/arm muscles are “inactive” is during the very short acceleration phase lasting 1/20 of a second. This is the amount of time the arm is “passively” whipped around by the body, from the position of external rotation (Point A) to the release point (Point B).

This necessarily short time frame is where the stored elastic energy that is generated during the cocking phase is expended. It is similar to the "amortization" phase of a plyometric exercise, where a muscle is first eccentrically loaded followed by concentric muscle action. This is also known as the "Stretch Shortening Cycle."

That this acceleration phase is of short duration does not diminish its importance, of course. It is vitally important.

Just keep in mind that during the remaining 98% of the pitching motion described by Pappas - cocking and follow through - the shoulder and arm pitching muscles are actively contracting, concentrically or eccentrically, along with muscles throughout the rest of the body involved in pitching.

And remember, 53% of the velocity of an overhand throw comes from the arm itself, with the trunk (stride/body rotation) contributing the remaining 47%.

Clearly this has implications as to how pitchers and all throwers should train, which we’ll continue to discuss in future issues of LD.

Based on what research tells us about how the body works, strong and flexible muscles will perform the mechanics of pitching more consistently and effectively and with less chance of injury.

1) American Journal of Sports Medicine, Vol 13, Issue 4 216-222, 1985 by American Orthopaedic Society for Sports Medicine.