More specifically, the two variables lead knee extension during delivery and forward trunk tilt at the instant of ball release. It has been my experience that forward trunk tilt at ball release is the cause while lead knee extension during delivery is the effect. In other words, lead knee extension is the sneeze to the forward trunk tilt cold.
I haven't always felt this way. I used to work on the lead knee extension variable with mixed results. Not until I started really focusing on forward trunk tilt did I see the lead knee extension really show up. It is my opinion, that if a pitcher truly commits to forward trunk tilt during delivery, the lead knee will extend to support the additional forces added to that leg. Implicit learning if you will.
Another caveat. Hamstring flexibility is a huge determinant in a pitchers ability to extend their lead knee if they are tilted forward at the trunk. It is also my opinion, that many pitchers, although committed to forward trunk tilt, may not be able to support it if they don't have the flexibility in the hamstrings.
Have you done any research with respect to hamstring flexibility in this area? I would love to see that variable in play in additional research projects.
Post by Dave Fortenbaugh, Ph.D. on Jan 14, 2010 10:27:15 GMT -6
I'm glad to see that you are interested in this study. Knee range of motion from foot contact to ball release and forward trunk tilt at ball release are key variables, and they are two of the first things we look at during our individual evaluations here at ASMI (http://www.asmi.org/asmiweb/evaluation%20options.htm).
You are correct that these two variables are connected, though I think you have inverted their relationship. Pitching involves transferring energy from the ground up. At foot contact, the knee is in a flexed position and the trunk is upright. It is the extension of the knee at this point in time that pushes the hips back and allows the trunk to lean forward (i.e. towards home plate).
Good lower body strength and flexibility aid in generating these movements by the knee, hips, and trunk. Off-hand, I do not know of any studies that have analyzed hamstring flexibility and pitching mechanics, but I will review the literature and let you know.
Thank you for the reply. A quick bio for me. I am a former #1 draft pick by the St. Louis Cardinals in '94. In college, I routinely threw in the 93-94 mph range. I never knew why, I just did. After reviewing my college video's, I did have very good trunk tilt and braced hard off the landing leg.
As I said in the previous post, I'm a big fan of your research studies. However, there is theory and then there is application. I have been trying to get back into shape and at least get back up to the 87-88 mph range. After watching video of my delivery, it was quite apparent that I wasn't bracing off the landing leg at all (in fact collapsing it!). Nor, did I have any forward trunk tilt.
I started working hard on the lead knee extension variable. Drill after drill. Get on the mound. The same collapsed leg would rear its ugly head.
Then, thinking about what happens to your center of gravity when you are tilted at the trunk, I realized that the bracing of the lead leg was the most efficient way to support the added forces when you are committed to that tilt. Guess what? Landing leg braced without thinking about it.
I am 37 years old and recently hit 89 mph again. Thinking only about forward trunk tilt!
I can assure you that a pitcher does not think nor should he think about "pushing" the hips back.
Dave, Just re-read my post. It comes across a little rough. Certainly wasn't my intention. I understand that you are coming at it from a research perspective whereas I am coming at it from a teaching perspective.
You are probably right, in that the lead knee extension does happen before the forward trunk tilt. However, when teaching the mechanics of pitching it may be more productive to focus on the forward trunk tilt.
Are you familiar with Nikolai Bernstein? He actually coined the term biomechanics. Anyway, he is widely regarded as the father of motor control. It is his contention that the body will organize itself to acheive it's desired goal. It will work in one unit and not independently to do this.
So, I'm thinking that from a coaching perspective if you focus on forward trunk tilt (desired goal) the body will do what needs to be done efficiently to make that happen (lead knee extension).
Post by Dave Fortenbaugh, Ph.D. on Jan 14, 2010 16:54:16 GMT -6
It's great to hear that you're still playing at 37 and are able to have close to the same velocity you did back in college! As a 29 year old former college player who still plays recreationally in the summer, I can somewhat relate
I appreciate your comments about what coaching points are most important and how to get through to athletes. If we diagnose what's wrong with a pitcher's mechanics but he is not able to translate our info into meaningful corrections, then our evaluation is not getting its full value.
I disagree, however, that a pitcher should not think about extending his knee and pushing his hips back. While it may have not worked for you to visualize your body's movements in this way, that does not necessarily mean that others cannot. I think it's good to have multiple "coaching points" because not all athletes can or will respond to the same visual, verbal, and/or physical cues.
Forward trunk tilt is pretty easy to visualize, but sometimes it can be difficult to achieve properly and to its fullest. Suggesting knee extension or pushing the hips back may help some to get a better understanding. Unfortunately, there are no research studies as of yet that have looked the coaching cues and drills that best correct certain mechanical flaws.
Also, knowing that forward trunk tilt is a by-product of knee and hip flexibility and strength can help guide a pitcher's strength and conditioning program to target any weaknesses. Physical limitations often present obstacles for athletes in correcting biomechanical flaws.
I'm not sure where you are going with this hamstring thing but I believe hamstrings flex the knee joint. Hamstrings do not extend the knee joint. Hamstrings extend the hip joint. Perhaps that is what you meant.
Bwags, I'm glad you liked that study. As you may already know, the complete study was published in a journal:
Matsuo T, Escamilla RF, Fleisig GS, Barrentine SW, Andrews JR. Comparison of kinematic and temporal parameters between different pitch velocity groups. Journal of Applied Biomechanics 17(1):1-13, 2001.