OH!

ok ok...
i noe i have a question!
so it bout those bands ya. so this my question:
 
why is it that when band ppl play and when they reach like a climax then they all jump while playing the guitars or sumthing. i dunno. why?
 
Poff does it. Shoe Size Nine does it. (yah yah i noe shameless publicity. but hey i'm doing PR ok??) Busted does it. Simple PLan does it. if i'm not wrong. Blink 182 does it also. go figure.
and the pic is from the gurl band The Temper Tantrums. i dunno if they are any good or not but hey i found the perfect example.
 
so how anyone has any idea why these guys do it? is it to improve sound? or is it that u feel so high that you feel you can fly!
i dunno. ANSWER ME! ( abit of sound of god there)
okyah good nightz