Those who cannot remember the past are condemned to repeat it. George Santayana
STRETCH-SHORTENING CYCLE (SSC)
The mechanical characteristics of skeletal muscle have such a major effect on the force and speed of muscle actions that the central nervous system has a preferred muscle action strategy to maximize performance in most fast movements. This strategy is most beneficial in high-effort events but is also usually selected in submaximal movements. Most normal movements unconsciously begin a stretch-shortening cycle (SSC): a countermovement away from the intended direction of motion that is slowed down (braked) with eccentric muscle action that is immediately followed by concentric action in the direction of interest. This bounce out of an eccentric results in potentiation (increase) of force in the following concentric action if there is minimal delay between the two muscle actions. Duane Knudson Fundamentals of Biomechanics Second Edition
The following is from a post that I made in the SETPRO forums on 5/30/2000.
By comparing “early” Steve to “present day” Steve and using info about the imprtance of elasticity, scapula loading, arm action path, etc, I could start to see what had changed in Avery.
The biggest difficulty in diagnosing Avery‘s problem is the change appears to have been a gradual process. It appears to have taken place over a 4-5 year period.
He did have an injury to his rib cage (1995?)which may have caused some of the problem.
Unless you really know what you are looking for, you would not see anything remarkably different.
Paul’s rule #203 states: “at the highest levels of performance, small changes create large results”.
Here’s the clip of Avery with Red Sox (horrible season, fast ball 82 MPH) to Avery, World Series 1991.
For the “video purists”, the camera angles for both clips are almost identical.
My estimate was that Avery had reduced his effective throwing path (length that force is applied over) by about 15% (maybe more).
He also lost a lot of “pre loading” (compare hand break “take back” path).
Clip on right (1991) looks more like a “slinger” (more horizonat take back of elbow, shoulder complex).
Clip on left (1997) he goes to the dreaded “high cock” (verticle lift of elbow, shoulder complex, does “jumping jack” ring a bell?).
As I said, when the “pedal is to the metal”, small changes can produce large effects.
Steve Avery throwing analysis that I did in 2000
Momentum is a vector.
Vector has direction and magnitude. Throwing speed (mph) and throwing efficiency (least amount of effort) depend on effectively transferring momentum. The most effective transfer of the body’s upper torso rotational momentum occurs when the arm moves in the same plane as the rotation of the shoulders.
This same principle holds true for the Stretch Shortening Cycle (SSC). The direction of stretch and then the corresponding contraction wants to take place in such a way as to maximize the application of force in the desired direction which in the case of throwing the baseball is in the plane of rotation.
Ideally the separation of ball from glove (hand break) wants to be centered we stretch the muscles in the plane around the upper spine in the direction that the shoulders will then rotate to create external rotation of the shoulder.
The clip of Steve Avery dramatically shows both reasonably good (clip on the right) and very poor (clip on the left) hand break (SSC) action.
The clip of Matt Harvey showing hand break also demonstrates less effective (left clip 93 mph) and more effective hand break (SSC) action (right clip 97 mph).
The clip on the left shows Harvey with more of a lifting of the arm upwards (vertical separation) in preparation to throw the baseball. Whereas the clip on the right shows Harvey with pulling back of the arm (horizontal separation).
Also there is a significant difference in the "intent" to throw the baseball.
Next in Part5: Development, storage and release of connective tissue elastic energy.