It remains to be seen if Rob Gronkowski is healthy enough to play professional football, but the Patriots tight end is still able to dance. During an appearance the other night on the ABC improv show “Whose Line Is It Anyway?” Gronk got his boogie on with host Wayne Brady and guest Jonathan Mangum. The Pats pass catcher revealed that he likes to dance — hardly news to anyone familiar with Gronk’s hard-partying past — and then demonstrated a few of his favorite moves, at one point stiff-arming Brady and bench-pressing Mangum.