Gary Gerard busts a move.

My father Gary Gerard (age 90) — demonstrated how strong his quads are when we were up at Stinson Beach for my sister Annie’s birthday recently.

(He goes to gym class 4x a week in Berkeley.)

Talk about the master of twerk!

I’m thankful that after all the physical challenges he’s gone through — two full knee replacements among them — that he can squat and smile like a Sumo wrestler.