Originally Posted by DropShotArtist
But if you keep the arm in line with torso as you said then the upper arm can't really be loose since if it was loose it would lag behind. And if it's not loose then there really is no transfer from torso to upper arm since it would be rotating as a unit with only the forearm and wrist lagging.
it should be loose. try standing with your arms to your side and your elbows bent a little. rotate your torso and try to keep your upper arm in line with your torso. no problem right? it takes virtually no energy or muscle to do that. it pretty much just happens. yes, i understand there is probably some muscle usage involved but it's very very little.
There should be no tension in your biceps or triceps or forearm. elbow is loose to allow forearm movement. the wrist is loose for the same reason. you want to maintain the hitting structure of your arm and racquet throughtout the stroke but you want to be loose to allow it to breathe and stretch. You want to swing fast, not hard. (i'm talking regular rally balls here not special circumstances/situations)
near contact you can activate things for spin etc like some pronation or wrist deviation etc but those movements, ideally, should not take a lot of muscle use, only very little. If you have the right contact point for your grip and swing style and a good setup at the end of takeback before the first forward movement then just before contact your arm and wrist will just be 'itchin' to pronate and deviate etc and if you just apply a little twist those actions will happen fast, smooth and naturally.