Have you picked him up and touched his wing to see if it hurts. If it does then he probably needs to see a vet. If they were fighting he may have gotten it dislocated or caught in the bars. I would get the vet to check it out just to make sure it isn't broken, they also have pain meds for birds.

one of my budgies keep lifting its right wing out and shaking it, kind of like shivering. he's been doing it for a while, sometimes i see him preening inside it, but most of the time he's just shaking it.

his friend got close to him, he flies off else where and shakes his wing. is there something wrong?

it's pretty cool here at the moment, so it's not the weather i dont think.

i feed him seeds, and broccoli, he loves broccoli. and i change water everyday.

my two budgies do fight some times, but with beaks only. he;s been shaking his wing for a couple of hours now. what could it be?