Originally Posted by Cheetah
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.
Since i have corrected the movement (racquet lag, not arm lag), it's almost been impossible for me to hit a ball flat without contact pronation and i have no idea what causes this. Only thing i know is, it's an unconscious motion and i don't use any muscle stress to activate it. I think it's about where you contact the ball like you explained.