Baseball Wear and Tear

[Charles Jenkins]

Rip, this conversation came up recently between some friends and me. We were discussing the prevalence of arm injuries among pitchers and the effects that a pitcher's velocity has on injury rates. Someone made the claim that a max effort pitch is equally damaging on the arm regardless of velocity (i.e. my can't-break-glass fastball max effort is just as tough on my arm as an MLB closer's 98-mph max effort is on his).

It seems to me that the harder thrower's pitches would be much more damaging, as kinetic energy has a quadratic relationship with velocity but there's not much reason to assume that the strength of the arm's connective tissues scales with higher velocity. In the comparison above, the MLB closer is generating (and therefore must absorb in deceleration) roughly 50% more kinetic energy than I am, and is therefore going to be more prone to damage to the arm.

Does this analysis seem correct to you?

[Mark Rippetoe]

What if his shoulder has adapted to the higher force output? As human tissue has a tendency to do.

[Charles Jenkins]

What if his shoulder has adapted to the higher force output? As human tissue has a tendency to do.

Sure, there's certainly adaptation there. So obviously the risk wouldn't scale 1:1 with the increase in kinetic energy. It seems to me that the damage would scale faster than linearly but slower than quadratically with velocity. Isn't it the case in general that more talented/explosive people are more able to generate injurious levels of internal force?

[Mark Rippetoe]

Sure. But it's also true that more talented people are better at learning how to not hurt themselves, and that this is one of the reasons you know who they are. The shoulder is not a mechanical device, and neither is the pitcher.

[Charles Jenkins]

Sure. But it's also true that more talented people are better at learning how to not hurt themselves, and that this is one of the reasons you know who they are. The shoulder is not a mechanical device, and neither is the pitcher.

But I want them to be, because then I could do math at them. Why is the human body so damned inconvenient?

[AndrewLewis]

But I want them to be, because then I could do math at them. Why is the human body so damned inconvenient?

Because 100 million years of evolution doesn't give a fuck about our convenience. It only cares about the ability to reproduce.

[Tiburon]

Does this analysis seem correct to you?

You might like The Arm by Jeff Passan. Good read about Tommy John, pitch counts, Nolan Ryan, etc.

[Charles Jenkins]

You might like The Arm by Jeff Passan. Good read about Tommy John, pitch counts, Nolan Ryan, etc.

My brother actually bought it for me in the wake of that discussion. I'm starting on it once I get the silly ACSM cert next month. Looking forward to it.