Thanks to all who have read and put some thought into what I have said thus far. I hope that with a little knowledge and a lot of hard work we can all have more fun at this game.
Before I go into details on the strength requirements for a hard leg plant, I am going to address a few of the questions that Roger has raised, and then get straight to it.
1- The first question from Roger I have written down was about the heel-toe landing, and do I believe people should land on their heel. (thanks for not correcting the bad spelling in previous posts! lol). Absolutely I do, however all pitchers will have the rest of their foot hit the ground a fraction of a second later, which you said. DO NOT land on the heel with tight ankle muscles which prevent natural full foot plant. we need our foot to be as solid as possible, to allow our knee to be as solid as possible, and so on.
2- Roger, you are absolutely correct that the body is more than a series of levers. I know you are considering just bone structure to be the levers and the muscles as acting on the bones to produce force. When I talk about levers, I generally refer to the whole system, muscles included. From now on I will take your frame of reference because it is easier to visualize.
3- Roger, you mentioned that you don't want someone to move as fast as they can, but you agreed with me that strength was a prerequisite for optimal momentum transfer. I will reword my point to provide the seguey to proper training for the plant:
The ultimate goal of pitcher leg training should be to be able to move towards the plate as fast as possible and still be able to plant optimally.
My numbers are a little off, but for sake of argument, lets shoot high and say that at landing, forces can reach about 1.5x body weight. That means a 200 lb pitcher lands with forces around 300 lbs.
It is the strength of the landing leg, specifically the quads, with help from the glutes and hip rotators, that must create a HUGE amount of force to plant quickly.
Also, in order to get out to around or just over 100% body length stride, which is required to plant optimally, you need exceptional full hip flexibility.
Finally, the force you develop MUST DEVELOP QUICKLY. I highlight this because "rate of force development", is not well understood by the general public. RFD is the time it takes to develop sufficient muscle tension to perform a motor task. This is term is best understood with the following example.
If a football player gets hit on the knee from the side and has sufficient muscle strength to absorb the blow, BUT the muscles dont respond fast enough, he will still get injured.
I am not here to lecture a sports injury class, so for further explanation, please do some independent research.
I am now going to set our some training goals, that if accomplished, SHOULD provide the base physical tools to plant optimally. I am not going to tell you how to advance from where you are, because I don't know where you are. You should be able to take these goals to a certified personal trainer and have them evaluate you relative to these goals.
For further reading and training suggestions, I highly recommend "Functional training for sport", by Michael Boyle. This book is the best I have come across and is a must for any serious athlete.
Strength: Be able to perform 3 sets of 10 of a full one legged squat, with perfect torso control.
balanced strength between the quads, glutes and hams, and ballanced strength on both legs
full splits in both directions, with the ability to roll back and forth- this may sound extreme, and it is, but we want to eliminate the possibility that muscle or joint tension is limiting hip rotation. It is especially important that hamstring flexibility be exceptional. Without it your body will not ALLOW you to plant at 100% body length. To achieve this I highly recommend Bikram Yoga. You don't even have to buy into the body mind focus part, but the training is the best I have found for flexibility.
RFD: read and follow the agility program in Functional training for sport. It does a far better job at explaining it than I can.
I firmly believe that a pitcher should overtrain for throwing, especially when we consider the legs. that is why I make these recommendations.
"shoot for the moon, because if you miss you will be among the stars"
Front Leg Freak