# Arm Length

All things being equal, does the length of a pitchers arm have any effect on the potential velocity it can…produce? achieve? Hopefully someone knows where Im going with this . Could this be one of the reasons most Major League scouts are looking for the taller guys? I know its just one piece of the pitching puzzle but the arm is one of the most vital.

Yes, all other things being equal, the amount of torque (rotational equivalent of force) that a pitcher can apply to the ball during his rotational movement leading up to release point is directly proportional to the length of his “moment arm”–that is, the distance the ball is held from the pitcher’s own rotational axis.

That is why short levers are not as effective as long levers, all other things being equal.

But the devil, as usual, is in the details…the longer the lever, the more difficult it becomes to accelerate it, and vice versa. So, “all other things” are rarely, if ever, equal…

I only could hope that is the case because i have a longer wingspan than my roommates who are bother pitchers in the 6’2 6’3 range

Could this fact, in and of itself, be the end to all questions regarding why they take tall and underdeveloped over short and 32 years old in an 18year old body. Or just tall guys in general. We rock. (no offense to anyone)

[quote=“Hoysauce”][quote=“laflippin”]

That is why short levers are not as effective as long levers, all other things being equal.

[/quote]

Could this fact, in and of itself, be the end to all questions regarding why they take tall and underdeveloped over short and 32 years old in an 18year old body. Or just tall guys in general. We rock. (no offense to anyone)[/quote]

I wouldn’t say short levers or short guys aren’t as effective. While it’s not mathematically possible to throw the ball as hard as taller guys, we can get the ball going just as fast, as stated it’s harder to get a longer lever accelerating faster. Us short levers’ are pocket rockets. Take a look at Jon Rauch, tallest guy in the league but little Tim Lincecum can throw harder. Us short guys rock too.

Heres another thing to think about.

A long lever made of pine wood won’t be as good as a short lever made of oak.

There are 6’3 guys on my team that have glass arms and are very sensative while we got a 5’9 guy who threw 80 innings and consistently went 7 8 innings deep per start

BillyBob,

I was quoted without full context:

[b]"That is why short levers are not as effective as long levers, all other things being equal.

But the devil, as usual, is in the details…the longer the lever, the more difficult it becomes to accelerate it, and vice versa. So, “all other things” are rarely, if ever, equal…"[/b]

I completely agree with you: Height is not a primary determinant of any of the following: pitcher’s velocity, his work ethic, intelligence, “heart”, or focus.

I felt the OP was basically asking about a principle of physics so that’s the way I tried to answer.

But, geez, obvious proof that short guys can throw the ball hard and be successful at all levels of baseball, including MLB, can be found all over the place…I don’t have to name all the names.

keep it simple. talent and execution get it done. hard workers and nice guys who cannot or do not know how to get it done do not win many games. that’s why guys with talent and 3 stints in rehab get another chance. they have that talent that you must buy.

kind of like the overused term think outside the box. you have to know what is in the box and how it works before you can find something else that will consistently work better. there are very good reasons things are the way they are. there are very few examples of dumb luck changing things over a long period of time.

there is a reason scouts select tall pitchers that throw hard and smaller guys that throw hard and change speeds. they tend to get elite level players out. and it’s their \$. that is the bottom line. they select and pay who they want to.

[quote=“laflippin”]BillyBob,

I was quoted without full context:

[b]"That is why short levers are not as effective as long levers, all other things being equal.

But the devil, as usual, is in the details…the longer the lever, the more difficult it becomes to accelerate it, and vice versa. So, “all other things” are rarely, if ever, equal…"[/b]

I completely agree with you: Height is not a primary determinant of any of the following: pitcher’s velocity, his work ethic, intelligence, “heart”, or focus.

I felt the OP was basically asking about a principle of physics so that’s the way I tried to answer.

But, geez, obvious proof that short guys can throw the ball hard and be successful at all levels of baseball, including MLB, can be found all over the place…I don’t have to name all the names.[/quote]

I wasn’t trying to be mean or anything…just had to stick up for us short guys.

[quote=“laflippin”]Yes, all other things being equal, the amount of torque (rotational equivalent of force) that a pitcher can apply to the ball during his rotational movement leading up to release point is directly proportional to the length of his “moment arm”–that is, the distance the ball is held from the pitcher’s own rotational axis.

That is why short levers are not as effective as long levers, all other things being equal.

But the devil, as usual, is in the details…the longer the lever, the more difficult it becomes to accelerate it, and vice versa. So, “all other things” are rarely, if ever, equal…[/quote]

I almost always agree with you Lee but I don’t follow the logic.

T (torque) = F (applied at the end of the moment arm) X D (length of moment arm)

T is created by the core which is translated into the arm, not vice versa. We don’t have an F created on the end of D to produce T. We are looking for maximum F, right?

F = T/D

If we have a “number” created by the core and we are looking for the maximum F (ball at the end of the moment arm), then theoretically the SMALLER D produces a larger F.

Actual translation happens with the smallest D possible for that pitcher. T is translated into external rotation with the arm at or near a 90 degree angle. Our D is not the length of the arm, but actually the length of the shoulder to the elbow. If max D were optimal, we would keep our arm extended straight out (ala Marshall).

Hi Rbish,

In my partial defense, the distance between shoulder and elbow is almost certainly in direct proportion to total arm length…so, I still maintain that the longer the arm length is the more torque can be generated, in theory, by equal force on it.

But, slippery guy that I am, I also carefully left a loophole for “real life”: “All things being equal”, to me, suggests that if equal force is brought to bear on levers of different length, then the longer lever will always allow for more accelerating torque on the ball. But “real life” experience suggests that some highly conditioned small guys may be able to generate higher forces against their shorter levers, and thus achieve the same kinds of accelerating torques that big guys can do. The flip-side of this coin is that big guys may have a harder time generating the force needed to accelerate their longer arms. Kind of Catch-22, there in my opinion.

So, my point all along is: It’s a wash…both groups, small guys and big guys, can throw the ball very fast, with sufficient conditioning/mechanics/genetics/health/etc. Not that that is any big news: As mentioned before, it is obvious that there are hard-throwing pitchers of small and large stature. There are also soft throwers among both groups.

To me, when used correctly, Newtonian physics can be a very compelling way to view and understand some aspects of human motion…but the laws of motion must conform to what is observably true at all times. (Which is one of the reasons that I like to monitor and study Mike Marshall’s many outlandish abuses of Newtonian physics: That scoundrel constantly invokes and misuses Newton in order to “prove” things which are very clearly not true.

Your point about Marshall’s mechanic is exactly to the point: Using his ideas, pitchers clearly cannot generate enough force to take advantage of their extended arm (longest possible lever) in pitching a ball. The motion analysis studies performed at ASMI of 4 Marshall pitchers make that very, very clear to everyone except, well…a few folks out there still believe Marshall’s version of reality, God bless them!