Dr. Fleisig, I am conducting a research project involving young throwing athletes 9-15. Has there been any study evaluating the kinetics/kinematics of a young thrower who has already experienced an injury? I look forward to your input. Any words of advice would be greatly appreciated. Kirch
Post by Glenn Fleisig, Ph.D. on May 16, 2005 8:04:57 GMT -6
As you probably know, ASMI published a paper on the kinematics and kinetics of healthy pitchers at various levels of development. Here is a summary and the reference: healthy young pitchers.
Unfortunately the issue of injured young pitchers is becoming a bigger and bigger problem. ASMI is currently studying the epidemiology of young injured pitchers (how old did they start pitching, do they throw curveballs, etc.), but we do not have a biomechanical study going. I think this would be a great idea, though.
There are a few other biomechanical labs in the country that might be looking into this. I will see if one of them has anything to contribute here.
Regardless of whether anyone else has looked at this or not, ASMI would be more than happy to provide advice or guidance in your research project.
I have some questions on marker placement. I have seen as many as 30 plus used and as little as 14 markers for the pitching analysis. Where do you place your markers now on your pitchers? Have you increased to the 30 plus as well. With the kinetics studies do use a standard weight for the ball? Also what software/programs are the best for measuring the kinetic data? I appreciate anyone's help with these issues. Jim
Post by Glenn Fleisig, Ph.D. on Aug 4, 2005 7:50:46 GMT -6
I have some questions on marker placement. I have seen as many as 30 plus used and as little as 14 markers for the pitching analysis. Where do you place your markers now on your pitchers? Have you increased to the 30 plus as well.
Up until now, ASMI has continued to use the 15-marker set described in our publications. We've used 14 or 15 markers for the past 15 years or so.
With ASMI's current move to a new lab, we are also upgrading our motion analysis system. Specifically, we are upgrading from a six-camera Motion Analysis Corporation "Falcon" system to an 8-camera Motion Analysis Corporation "Eagle4" system. There are many improvements in the new system - such as "real-time" data collection, but the biggest improvement is in camera resolution. When taking about 200 pictures per second, a Falcon camera has about 500 columns x 300 rows of data points (about 150,000 pixels or data points each pictiure). At 200 pictures per second, an Eagle4 camera has about 2,000 columns x 2,000 rows of data points (4,000,000 pixels). With about 20 times the resolution of our old system, ASMI will be able to use smaller markers and more markers. The greater resolution is particularly important when using small subjects, like some kids in your population. For more information about the Eagle4 technology, contact Dan India at Motion Analysis Corporation (email:email@example.com, website:www.motionanalysis.com.
With the kinetics studies do use a standard weight for the ball?
Typically we use standard 5-ounce baseballs. However, ASMI recently completed a study with 10-12 year old pitchers throwing 4-ounce baseballs. Results from this study imply that the lighter ball might be a good choice for younger pitchers. This study is currently in review for publication at a scientific journal.
Also what software/programs are the best for measuring the kinetic data?
At ASMI, we have written our own software. The equations we've used are well-documented in our scientific publications. If you use a Motion Analysis Corp. system, you should consider buying a new software package they now sell called "UETrak." Their is information about UETrak in the "MOCAP News" section of the www.motionanalysis.com website.
In an interview with Baseball Prospectus you mentioned two key checkpoints in pitching mechanics. "Is he in the right position to throw?" and when a pitcher releases the ball you should be able to draw a line through the shoulder that hits the elbow. Could you post some pictures of these positions? Are there any other major checkpoints when it comes to injury prevention?