I mentioned last spring that we (myself and a couple classmates) were doing a biomechanics project on the difference between GRF in expert and novice batters, and at the time I didn’t want to bother putting up our results. The main reason was that it was our first time using the equipment - a force plate and Peak Motus 2-D analysis system – but it is a little more interesting now that I look back at it. I will be the first to say, however, that this is not something I’d believe to be publishable or anything to that degree. Just a class project designed to get us familar with the equipment. Moral of the story:
don’t read into it too much!
OK here goes:
1.) This first graph shows the amount of VERTICAL GRF created by both expert and novice grouns under two conditions – stride and no stride. The only significant difference was in the stride condition where the novice group, 3 college students in our department, had a much higher vertical GRF.
What threw me off a little was that the expert group, three college hitters, actually had a lower GRF in the no-stride condition. My only explanation for that, from an observational standpoint, is that their no-stride condition swings seemed closer to what their natural swings would be. For example, in the stride condition, I literally had to remind them that they needed to lift their front foot off the ground.
2.) The second one simply shows the correlation of bat velocity to GRF. In both conditions, the novice group showed a high correlation to GRF produced and bat velocity. Simply put, the more GRF they had, the more bat speed they had.
This was not the case in the expert group. They showed minimal correlation in both conditions. What this suggests is that they are relying much less on weight shift in the direction of the pitcher for bat speed production. I believe the golf study I have (left it at home today, unfortunately) attributed just 10% of club head speed in experts to weight shift, and this would agree with the results here. In other words, the experts are relying on other means, namely summation of forces from the sequential rotation of body parts – aka kinetic link – to develop bat velocity.
Steve Englishbey got me going a few weeks ago on the topic of Ground Reaction Forces in batting. While there isn’t a ton of stuff directly pertaining to baseball, I have managed to dig up a couple of studies specifically directed at baseball/softball batting, and there are others as well that deal with other sports (like golf).