Biomechanical Research

by HuskerBob on Nov 7, 2007 1:00 PM EST

I've tried several times to state my beliefs about the causes of arm injuries (particularly in cases like Liriano) and never felt like I was saying what I meant. I found some interesting information that I think says things more clearly than I have been able to. This from the James Andrews American Sports Medicine Institute:

"High-speed motion analysis of 72 healthy college and professional pitchers was used to investigate correlations between improper kinematics and increased elbow and shoulder joint kinetics."

"At the elbow, a significant correlation was seen between increased medial force exerted onto the forearm and two kinematic parameters: increased shoulder external rotation at the instant of foot contact, and increased horizontal adduction. "

Early external shoulder rotation and increased movement of the elbow from the center of gravity, so to speak, lead to increased medial (UCL) force exerted on the elbow.

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Video

It would be nice to be able to see video examples of the movements they talk about with a narrator pointing out the features. Doubt anything like that exists in public domain, though.

by DrBGiantsfan on Nov 7, 2007 1:15 PM EST reply actions

what steps do you take

in your instruction to avoid these injuries to the arm? Do you have video anlysis of your students where these are the "watch-outs" in viewing?

Just curious because I value your perspective when it comes to pitching mechanics.

by So Cal Bob on Nov 7, 2007 1:48 PM EST reply actions

Still Shots

I'll see about uploading some of the still shots I have of some of the pitchers I've worked with. Some good ones and some bad ones.

The kids I work with are 11-17 and have hard time with the "feel" of what their body is doing. We talk alot about dynamic balance queues at certain points rather than a more in depth "feel" conversation you might have with a college or pro athlete that understand their body's tempo and coordination.

The drills I've seen the best results from in terms of staying closed, other than verbal queues, are the Rocker Drill and kneeling catch. In my experience, you really have to exaggerate the separation of the hips and shoulders to get the point across. Staying closed becomes less of an issue, in my experience as a youth starts being able to place the ball where they want. The first time they rare back on a fastball and paint a corner on purpose they usually buy what you are selling.

In terms of horizontal adduction/abduction, I focus mostly on the head. I'm of the belief if the head is in the right spot, the body will follow. Combine that will equal and opposite verbage in terms of arms through front foot strike and you can usually keep a kid on track.

That said, I'm talking about average athletes at a very low level. When you are talking about supreme athletes with coordination and balance that are off the charts I can see how many organizations and pitching coaches take the approach not to screw up a good thing. In that context, if it were my job (haha), I wouldn't be looking at whole sale changes to guys on that level. Just minor tweaks that maybe save on the damage.

Lex clavatoris designati rescindenda est.

by HuskerBob on Nov 7, 2007 2:57 PM EST reply actions

agree 100%

I work w/ 16-13 yr olds, for most all of them its a step by painfully slow step to get them to understand their own mechanics, how their own body works relative to the task at hand. I stress balance, balance, and more balance, also big emphasis on where their head is and keeping it still as possible. Too many of them are horrible from the stretch, and I was told not to teach them a slide step (as most college kids have trouble learning this without rushing).

Could you explain/guide me to what the rocker drill & kneeling catch is if not too much trouble? A few I currently use: throwing sock balls, mirror or shadow pitching (slow motion step by step), towel drill (good to get them down to a proper stride)

Mulder: Babe Ruth was an alien? Arthur Dales: sure; all the great ones were aliens.

by dew on Nov 7, 2007 5:58 PM EST reply actions

one of the best x-files episodes ever!

Curtis Granderson fan

by jrose643 on Nov 7, 2007 8:54 PM EST up reply actions

ha

was wondering when someone would ID it ... and it was just on TNT a wk or so ago. Yeah The Unnatural is one of my favorites too.

Mulder: Babe Ruth was an alien? Arthur Dales: sure; all the great ones were aliens.

by dew on Nov 7, 2007 9:43 PM EST up reply actions

Rocker Drill

Most pitchers, as soon as their stride foot hits the ground, here comes the front shoulder (which is why the slide step causes a loss in velocity for most). The Rocker drill gets them in the position of front foot strike with arms equal and opposite and the lead shoulder closed. From there you get them to "rock" their weight forward with their hips while closing up the front side. It takes a long time for most to get the feeling of stride foot down while they are still closing the front side. I have a video of Andy Pettitte that I show them that is excellent, although he is a little different than most. His stride foot hits and his lead shoulder is still going UP. Pettitte is one of my favorite pitchers to highlight. Here is a youtube clip of him doing another drill I use, right foot behind the left (left behind right for southpaws) while warming up that exaggerates closing up the front side:

http://www.youtube.com/watch?v=t4FPZmD6dZo

NPA has an IPOD download that explains the Rocker Drill and the kneel throwing:

http://www.nationalpitching.net/iclips.asp?

About halfway down the page.

Kneeling throwing does a couple things (I start every workout with this). I have them kneeling with knees facing the target (NPA clip says 45 degree angle but I like the over exaggeration) and they rotate their shoulders to close off the front side. They really get the feel of the hip and shoulder separation. Then as they throw I emphasize keeping the glove in front of their body, which will cause them to fall forward after release. After a couple weeks of this you really see them extending their stride length and percent stride length at release.

Lex clavatoris designati rescindenda est.

by HuskerBob on Nov 8, 2007 10:00 AM EST up reply actions

thanks

it is what I thought it was. Thanks again.

Mulder: Babe Ruth was an alien? Arthur Dales: sure; all the great ones were aliens.

by dew on Nov 9, 2007 3:33 PM EST up reply actions

Is that you Denny Green?

"They are who we thought they were!"

Lex clavatoris designati rescindenda est.

by HuskerBob on Nov 9, 2007 3:40 PM EST up reply actions

question

Does that suggest pitchers who land on their front leg early and then have significant arm/shoulder motion are at a higher risk than say pitchers like Lincecum who are at the other extreme with almost all arm motion complete by the time he lands on his front foot?

That is what I saw, am I correct in thinking that?

I'm skipping the elbow portion as that seems a slightly different motion to me.

by pedrophile on Nov 7, 2007 7:28 PM EST reply actions