I've tried playing with my buddy a defence game where you don't smash but for every mistake you make during the rally, you put 25 cents into a "food pot" which is used later when going out to eat. Makes the game very very very exciting!!!
I have seen a guy playing with his other hand carrying a plastic chair in a serious match. Serious = heavy betting.
Well, I meant very minimal upper arm input... using as much as possible grip tightening and pronation/supination to generate power.
http://www.badmintoncentral.com/forums/showthread.php/139716-grip-tightening-for-overheads Here's a link.
Finger power is a technic that was developed by the Indonesians and Chinese (I believe).The badminton racket is not to be held in the palm of your hand but rather held in your fingers. It's a very relaxed position and for touch shots provides more feeling (net shots and drops).For power shots such as clears, smashes, and pushes you tense your fingers while rotating your wrist. this can develope almost double the power and can give you a little more control. so, more consistent. but depending on the shot your playing, you dont always tense ALL your fingers. forehand pushes use middle and ring fingers, backhand pushed use thumb, middle, ring, and pinky.etc...
Make your court position to open up the Backhand side. Force yourself to hit more BH instead of around the head FH