Mailbag #2 – A couple of comments
JP’s comment stated the need for sufficient strength in order to maintain correct sequence patterns.
The following was part of my initial response response:
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For example, weight distribution at the time of stride foot plant will effect how rotation takes place.
On top of that, I’d agree with JP in a case such as Francoeur that a possible plan of attack would be to focus on concentric strength in diagonal rotation patterns in order to improve swing quickness. Assuming a player can ‘get away with’ more separation, it could be a good thing — just have to make sure the swing is executed in the given time period.
I’ll also mention again, if you have not checked out the JP Fitness Forum, it is worth a visit.
#2 – anonymous comment goes like this:
I have to add there that those not experience taking swing without a stride had a bigger difference. Similar to my comments on my biomechanics project. This was mainly because they heavily relied on thier arms, dragging the bat, etc. to create bat speed. Over time, they learned to use their body more efficiently to produce bat speed and quickness.
Research wise, the only number I can reference specifically is from a golf biomechanics study that quantified a 10% contribution from lateral movement/shift prior to launching the swing.
Baseball studies show weight bearing on the front foot to be greater than 100% of body weight at the time the stride foot lands, which suggests the need to get the weight shifted to the front leg. Actual picking up of the foot is really a matter of preference, comfortability (ie. golfers have the same shift without the actual stride).
My word of caution about trying to create too much bat speed by way of the stride is this – while a biomechanics study on ground reaction forces in pitching did show a correlation between total ground forces produces and linear wrist velocity (speed of the throwing hand moving toward it’s target at release), GRF that peaked too soon showed a negative correlation to the same wrist velocity.
My interpretation of that is basically if you push (forcefull extension of back leg) too soon, then you’re in troube. Rather, you’re looking for a controlled build up of momentum leading to forceful, late rotation as the stride foot begin to land.
Personally, I usually focus on reaching good athletic positions, instead of a set idea of stide length. Especially with objective feedback, players tend to figure out which positions are good and not so good.
First of all let me say I am a big fan of the work you have done. Every piece you have done has been right on in my opinion, except for one thing. In your Zoomlander article, you seemed to like the fact that Zumaya raises his pitching elbow above the plane of his shoulders. From what I have seen, this both increases velocity and often leads to arm problems. Examples of pitchers who raises their pitching elbow above the plane of the shoulders and are currently on the DL are Mark Prior, Kerry Wood, and Fransisco Liriano. At least for starters, it seems like the risk outweighs the possible reward.
Looking froward to your response.
Eric -
I tried to provide a brief explanation of Zumaya’s arm action/velocity with this image:
http://swingtraining.net/clips/pitcher1.gif
The tradeoff is that should abduction (raising your arm to the side) and internal rotation CAN cause shoulder impingement.
Of the three you mentioned, Prior is the one with shoulder problems and he was diagnosed with “laxity” of the ligaments in his shoulder, suggesting that he stability problems in the shoulder. Whether or not that was a result of how he throws, I have no way of knowing.