Yes, MASSAGES is a Scrabble word!

Letter values in Scrabble US: M 3, A 1, S 1, S 1, A 1, G 2, E 1, S 1.

Is it a valid word?

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

kneading and rubbing parts of the body to increase circulation and promote relaxation

manually manipulate (someone's body), usually for medicinal or relaxation purposes
give a massage to

Also: rub down.