I was recently checking out some slow-mo clips of top-ranked college pitchers and I came across a video of this kid named Logan Verrett, now a sophomore at Baylor. At 6’2” 170lbs the kid is a beanpole, and yet he was gunned as high as 94 mph when this clip was taken his freshman year. Given another couple years to keep maturing and build up some strength, this kid should be touching upper 90sby the time he’s draft eligible. The scouting report on this website had only positive things to say about him, until it mentioned that his mechanics included a common flaw of “traditional” mechanics: “reverse forearm bounce.”

I was scratching my head at this point. That’s a BAD thing? You see, every high level thrower (yes, this includes outfielders and anyone else who throws at least mid 90s) that I have ever seen, not to mention nearly all amateur players as well (to varying degrees) exhibit this mechanical trait. But I’m getting ahead of myself. Let me first present you with the definition of “reverse forearm bounce” that the website provided, and explain why it was called a “flaw.”

Logan Verrett

Reportedly coined by Mike Marshall, this “bounce” refers to “the downward motion of the pitching forearm caused by the inertial mass of the ball, pitching hand, and pitching forearm.”

That is, the “forearm layback” that every high level thrower exhibits. I’m not really sure how many examples I need to supply our readers with to prove this point, so I’ll just include some synchronized clips of a diverse assortment of both active and retired high level throwers (some have been flipped to appear as lefties). These throwers range in peak velocity from mid 90s to in excess of 100 mph.

**Note that I did not use photos as evidence for my claim. Although photos are far better than nothing, and in this specific case may have sufficed, when it comes to illustrating a point that has to do with mechanics, photos can be taken way out of context. For example, a player reaches landing position with their hips open, shoulders closed, throwing arm vertical – the classic “high cocked” position…but how did they get to that position? Unless you have a very trained eye, it can be hard to tell much from just a photo of a player at landing position unless you know how to look for subtle cues that give away how they got there (elbows pinched back, back foot turned over, etc.) So to better make a point when it comes to mechanics, do yourself a favor and learn to use clips to illustrate this kind of thing (maybe this will be the topic of a future post if there is sufficient interest).**
So what reasons did the website give as to why “Reverse forearm bounce” was a flaw? And, additionally, is this something that can (or should) be fixed, or is it just an inherent, albeit stressful, part of throwing hard?

This particular website cites various studies showing that the more extreme the “bounce” and the closer the throwing elbow is flexed to 90, the greater the stress will be on the UCL. Is this true? Yes, I have no reason to doubt the studies – in fact, I would have been surprised if this was not what the studies had concluded. My point though, is that high level throwing is inherently stressful on shoulder and elbow – this is apparent from looking at ANY 95 mph thrower, noting the elbow flexed to 90 degrees during acceleration, and the ridiculous amount of external rotation (near 180 degrees) at the glenohumeral joint. To go a step further, I’m asserting that the very mechanical traits that allow a player to hit such high velocities are the same traits that place the most stress on the throwing arm. That is, the “bounce” is necessary because it

1.    increases the range of motion over which force is applied to the baseball.

If we’re trying to maximize velocity (v= distance traveled/time) then one way to do it is increasing distance traveled over which force is applied to the ball while holding time constant. Thus, a player with a full 180 degrees of external rotation is going to throw harder than a player with 160 degrees of ER if all other variables are held constant.

2.    increases the reflexive action and thus strengthens the following concentric contraction of the internal rotators of the shoulder due to the Stretch Shortening Cycle.

The SSC basically says that when you eccentrically lengthen a muscle under tension (in this case all the internal rotators) it will store elastic energy (like a rubber band) which can then be used to strengthen the following concentric contraction. The quicker and more powerful the “Stretch” the more powerful the resulting contraction has the potential to be (provided all of it can be harnessed).

What though, is the significance of this conclusion? What should you do with this knowledge? Should you stunt your potential as a pitcher by focusing solely on reducing the stress to your UCL? (see marshall video) That depends on your goal. If you’re attempting to reach the highest levels of the game, it’s pretty much a given that you need a good fastball. Like it or not, scouts don’t care about 85 mph fastballs unless you’re absolutely flawless in every other aspect of your performance. Even Greg Maddux had a low 90s heater out of high school…without it he may not have ever been given a shot at professional ball. If, however, you just want to have fun, allegedly improve your chances of staying healthy and in all likelihood not make it past high school ball then by all means, reduce your “reverse forearm bounce,” stop trying to throw hard and follow the advice of this scouting report and of Dr. Marshall (see video). Otherwise, keep throwing the crap out of the ball, making sure to manage as best as possible the inherent risk that accompanies these throws. Guys like Eric Cressey have figured this part out pretty damn well.

Dr. Marshall showing how to allegedly reduce UCL wear and tear while simultaneously stunting velocity:

Marshall

I don’t even know where to start on this video, so I’ll leave it to you to decide what to make of it for now. I look forward to hearing your comments and opinions!