It’s easy to compare Internet sensations Trevor Bauer and Dylan Bundy—they both are huge proponents of “extreme” long toss (300+ feet), they both have unorthodox workout plans, and they have similar mechanics, though Bauer has a more exaggerated “C posture” like Tim Lincecum has at ball release. But Tyson Ross? He’s their polar opposite—a short stride with a low three-quarters delivery.
Looking at their pitching mechanics from the side, it becomes clear how Bundy and Bauer both heavily rely on the lower half to generate their plus velocities, while Ross doesn’t (huge file, tried to cut it down as much as possible):
Beyond the lower half, there are a few things I’d like to point out. The first is the obvious difference in max trunk forward flexion among the three right after ball release:
You can see that Ross is fairly upright while Bauer and Bundy have significantly more forward flexion. In Comparison of Kinematic and Temporal Parameters Between Different Pitch Velocity Groups (Matsuo et al – link), “…forward trunk tilt at the instant of ball release… [was] significantly greater in the high velocity group.”
Additionally, trunk forward flexion is thought to give pitchers a longer deceleration path, thus reducing peak loads on the posterior (rear) shoulder. This is comparable to why larger values of Maximum External Rotation (really Maximum Forearm Layback, but that’s another debate) are desirable; the ball can be accelerated over a greater distance and a longer period of time, thus creating higher ball velocities. The deceleration paths of Bauer and Bundy vs. Ross couldn’t be more staggering when slowed down:
You can see that Ross has a secondary recoil with his pitching arm, indicating his arm has not yet dissipated all the force from the delivery. If you look closely, you can see that Bauer and Bundy do a much better job of rotating their pitching arm shoulders into the target as well, which should help the larger muscles in the back (latissimus dorsi, mainly) to take on the deceleration forces.
Training for deceleration
Mechanical changes aren’t the only ways this issue can be addressed. In a YouTube video I published, I talked about how the posterior shoulder could be trained to withstand these forces:
Other pitching coaches agree with this philosophy, from the mainstream – Tom House‘s NPA Velocity program to the “crazy” alternatives, like Dr. Mike Marshall, who has been advocating the use of wrist weights to train in a ballistic fashion to strengthen eccentric contractions in the shoulder (this is former first-round pick Tyler Matzek training with Lon Fullmer, a certified Marshall coach):
Bundy uses a punching bag routine to train the posterior shoulder:
Bauer uses bands to do reverse throws (and Wolforth’s camp is known to do medicine ball rebounder work as well):
Secondary issues: Cascade injuries
Deceleration forces are largely responsible for posterior shoulder stress, but also can affect the elbow in a general sense. If peak forces in the shoulder are larger than a desirable range for a given ball velocity, fatigue in the smaller muscles can set in rapidly, which can greatly alter movement patterns (mechanics) of the delivery. Experts widely theorize that altered mechanics are responsible for injuries in the pitching arm (my research indicates larger variance in vertical release point could be linked to elbow injuries), so this is clearly a red flag.
The proper approach to player development will take a multivariate approach—using high-speed video and kinematic/kinetic analyses for mechanical flags, prehabilitation protocols to build up posterior shoulder strength and elbow stability, and active trainer intervention through massage, active release technique, and other soft tissue manipulation methods—to keep pitchers healthy and throwing as hard as possible.