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I've been brewing around ideas on how to actually teach and develop good service biomechanics, and hopefully will have some youtube videos up in the not too distant future (still want to master the technique myself and see if I can help others before going "public").
John's latest article on the upswing inspired me to flesh out some of these thoughts:
One thing I've thought about is how practicing small chunks of the service motion relates to actual serving. For example, I've spent a lot of time with myself (and a bit of time with others), working on the latter portion of the upward swing. First I teach them what internal shoulder rotation is, and how it affects the racquet head path during the upswing. Then I explain elbow flexion, and elbow pronation (though I emphasize that internal shoulder rotation is far more important than elbow pronation).
Now when someone practices this portion of the serve in isolation, the pattern of independent torque vs. motion dependent torque is likely different from when you are using a full service motion. In the isolated motion, you arguably have to consciously activate the internal rotators and triceps to a larger degree, as they cannot derive their torque from the forward angular momentum channeled up through the torso. On the other hand, when one is practicing these motions, it's usually at a much slower pace than during a real serve, so perhaps this balances things out in terms of intensity of muscle activation.
Either way, I still think it's incredibly useful to go through these motions as it still provides kinesthetic feedback that is relevant to the real service motion. My knowledge of muscle neurophysiology is limited, but I think that there are receptors in the muscle tissue that fire regardless of whether the joint is actively or passively rotated. In particular, the temporal pattern of this kinesthetic feedback may generalize to full serving mechanics and can thus reinforce good serving mechanics.
Another related limitation of isolated practice is that you don't experience the same muscle loading patterns (stretch shortening cycle) as you would when you have momentum being passed up from the torso. However, in my experience as a developing athlete, learning to harness muscle loading is something that comes quite naturally. So I don't think that practicing isolated movements will interfere with learning to use muscle loading as one progresses to fuller mechanics.
Which leads me to the last point... progressions. I think a geat progression model is to start at the final portion of the motion (latter part of upswing), and then progressively add antecedent elements in cumulative fashion. One good heuristic may be to wait until the student is able to achieve a great whip motion until progressing to the next step. By a great whip motion, I mean utilizing the available kinetic chain to produce good racquet head speed (safety considerations may have to apply here, as attempting to generate high racquet head speed with isolated motions may put dangerous stress on relatively weak joints such as the shoulder, elbow and wrist). By employing this approach, the student has a series of well defined goals and can learn to discover good mechanics. As they progress, they can learn to keep their arm loose and relaxed, as they let the legs and torso (and hopefully "imprinted" patterns of muscle activation) guide the motion.
I'm going to test this out on friends, as well as myself. I'm thinking about teaching myself to serve with my left arm (I'm extremely right hand dominant), as I think this will be a good test of these ideas, and may also give me some useful teaching insights.
-Marwan
John's latest article on the upswing inspired me to flesh out some of these thoughts:
One thing I've thought about is how practicing small chunks of the service motion relates to actual serving. For example, I've spent a lot of time with myself (and a bit of time with others), working on the latter portion of the upward swing. First I teach them what internal shoulder rotation is, and how it affects the racquet head path during the upswing. Then I explain elbow flexion, and elbow pronation (though I emphasize that internal shoulder rotation is far more important than elbow pronation).
Now when someone practices this portion of the serve in isolation, the pattern of independent torque vs. motion dependent torque is likely different from when you are using a full service motion. In the isolated motion, you arguably have to consciously activate the internal rotators and triceps to a larger degree, as they cannot derive their torque from the forward angular momentum channeled up through the torso. On the other hand, when one is practicing these motions, it's usually at a much slower pace than during a real serve, so perhaps this balances things out in terms of intensity of muscle activation.
Either way, I still think it's incredibly useful to go through these motions as it still provides kinesthetic feedback that is relevant to the real service motion. My knowledge of muscle neurophysiology is limited, but I think that there are receptors in the muscle tissue that fire regardless of whether the joint is actively or passively rotated. In particular, the temporal pattern of this kinesthetic feedback may generalize to full serving mechanics and can thus reinforce good serving mechanics.
Another related limitation of isolated practice is that you don't experience the same muscle loading patterns (stretch shortening cycle) as you would when you have momentum being passed up from the torso. However, in my experience as a developing athlete, learning to harness muscle loading is something that comes quite naturally. So I don't think that practicing isolated movements will interfere with learning to use muscle loading as one progresses to fuller mechanics.
Which leads me to the last point... progressions. I think a geat progression model is to start at the final portion of the motion (latter part of upswing), and then progressively add antecedent elements in cumulative fashion. One good heuristic may be to wait until the student is able to achieve a great whip motion until progressing to the next step. By a great whip motion, I mean utilizing the available kinetic chain to produce good racquet head speed (safety considerations may have to apply here, as attempting to generate high racquet head speed with isolated motions may put dangerous stress on relatively weak joints such as the shoulder, elbow and wrist). By employing this approach, the student has a series of well defined goals and can learn to discover good mechanics. As they progress, they can learn to keep their arm loose and relaxed, as they let the legs and torso (and hopefully "imprinted" patterns of muscle activation) guide the motion.
I'm going to test this out on friends, as well as myself. I'm thinking about teaching myself to serve with my left arm (I'm extremely right hand dominant), as I think this will be a good test of these ideas, and may also give me some useful teaching insights.
-Marwan