DD used the Finch trainer several years ago for 3 months and it produced about 2 mph improvement. At the time she was working with an instructor that taught the push type motion. About a year later we switched her to a whip mechanic and since then she has gained about 12 mph. Part of this improvement can be attributed to maturing and strength gains to be sure. While these gains are purely anecdotal they do lead me to the following conclusions.
The Finch trainer promotes good shoulder rotation, but its primary benefit is in strengthening the shoulder. It is fundamentally an exercise machine. The strength increase achieved should in and of itself reduce the potential for injury and would likely be demonstrable in a before and after study. One would likely see modest gains in speed if used regularly, but those gains are limited.
A whip arm circle requires lag – the elbow trails the shoulder; the hand trails the elbow until the hand whips past at release. It is an absolute and can be clearly seen in the Finch clip. Attempting to do a whip arm circle with the Finch trainer is nearly impossible and would likely cause injury because it would put a significant amount of stress on the shoulder from 12 o’clock to release.
The reason for this is one has to set the resistance relatively high and continue to increase the resistance in order to gain shoulder strength. This requires a push arm circle because the resistance is constant throughout the circle. This constant resistance means that the arm and shoulder are trying to accelerate the ball from zero through every degree of the circle - there is no momentum.
In a whip pitching motion there is also a constant resistance at the shoulder while the ball is lagging behind, but the ball is also accelerating. At the general point where the internal rotation of the arm occurs, the ball is accelerating faster than the shoulder.
The several studies I have seen state that for overhand pitching the majority of injuries occur during the deceleration phase, while the majority of injuries in underhand pitching occur during the acceleration phase.
It would seem to me that the shoulder has to be accelerating through the spin/release phase of the motion with the push model otherwise the ball would slow down. This means there is a constant resistance in the shoulder to accelerate the ball through the entire motion – the very feeling the Finch trainer promotes. In the whip model the shoulder accelerates through the first three quarters of the motion – more or less. During the spin/release phase the shoulder is decelerating as it transfers energy into the arm. At that point the shoulder rotates to support the internal rotation of the forearm – basically a separation of duties – an entirely different feeling than is achieved from the trainer.
Both the whip and push models have potential for injury. The constant acceleration of the shoulder in the push model puts a significant amount of stress on the shoulder at release, but is fairly easy to sequence. The amount of lag and the timing of internal rotation of the whip model are more difficult to sequence and can put additional stress on the shoulder if not sequenced correctly.
As one increases the amount of energy put into an action the potential for injury increases so one has to develop the underlying strength to support the action. So the Finch trainer is a useful piece of exercise equipment and can reduce injury by strengthening the shoulder. But, there is a limit to how much one can accelerate the shoulder and no amount of additional strength will produce significant improvement or reduce the risk of injury – there is a point of diminishing returns.
The difference in mechanic is another matter. One can accelerate the shoulder equally in push and whip mechanics. Because of this the push mechanic is a dead end. Spin and speed are tied directly to shoulder acceleration in the push model. In the whip model the lag to internal rotation creates an additional source of both speed and spin.
The risk of injury can be mitigated in either mechanic by proper strength and conditioning programs among many other factors.
The Finch trainer promotes good shoulder rotation, but its primary benefit is in strengthening the shoulder. It is fundamentally an exercise machine. The strength increase achieved should in and of itself reduce the potential for injury and would likely be demonstrable in a before and after study. One would likely see modest gains in speed if used regularly, but those gains are limited.
A whip arm circle requires lag – the elbow trails the shoulder; the hand trails the elbow until the hand whips past at release. It is an absolute and can be clearly seen in the Finch clip. Attempting to do a whip arm circle with the Finch trainer is nearly impossible and would likely cause injury because it would put a significant amount of stress on the shoulder from 12 o’clock to release.
The reason for this is one has to set the resistance relatively high and continue to increase the resistance in order to gain shoulder strength. This requires a push arm circle because the resistance is constant throughout the circle. This constant resistance means that the arm and shoulder are trying to accelerate the ball from zero through every degree of the circle - there is no momentum.
In a whip pitching motion there is also a constant resistance at the shoulder while the ball is lagging behind, but the ball is also accelerating. At the general point where the internal rotation of the arm occurs, the ball is accelerating faster than the shoulder.
The several studies I have seen state that for overhand pitching the majority of injuries occur during the deceleration phase, while the majority of injuries in underhand pitching occur during the acceleration phase.
It would seem to me that the shoulder has to be accelerating through the spin/release phase of the motion with the push model otherwise the ball would slow down. This means there is a constant resistance in the shoulder to accelerate the ball through the entire motion – the very feeling the Finch trainer promotes. In the whip model the shoulder accelerates through the first three quarters of the motion – more or less. During the spin/release phase the shoulder is decelerating as it transfers energy into the arm. At that point the shoulder rotates to support the internal rotation of the forearm – basically a separation of duties – an entirely different feeling than is achieved from the trainer.
Both the whip and push models have potential for injury. The constant acceleration of the shoulder in the push model puts a significant amount of stress on the shoulder at release, but is fairly easy to sequence. The amount of lag and the timing of internal rotation of the whip model are more difficult to sequence and can put additional stress on the shoulder if not sequenced correctly.
As one increases the amount of energy put into an action the potential for injury increases so one has to develop the underlying strength to support the action. So the Finch trainer is a useful piece of exercise equipment and can reduce injury by strengthening the shoulder. But, there is a limit to how much one can accelerate the shoulder and no amount of additional strength will produce significant improvement or reduce the risk of injury – there is a point of diminishing returns.
The difference in mechanic is another matter. One can accelerate the shoulder equally in push and whip mechanics. Because of this the push mechanic is a dead end. Spin and speed are tied directly to shoulder acceleration in the push model. In the whip model the lag to internal rotation creates an additional source of both speed and spin.
The risk of injury can be mitigated in either mechanic by proper strength and conditioning programs among many other factors.
