Yes, SCRUNCHING is a Scrabble word!

Letter values in Scrabble US: S 1, C 3, R 1, U 1, N 1, C 3, H 4, I 1, N 1, G 2.

Is it a valid word?

SCRUNCHING is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

make a noise typical of an engine lacking lubricants
sit on one's heels
make wrinkles or creases on a smooth surface; make a pressed, folded or wrinkled line in

Also: scrunch up, hunker down.