I think Amanda has it, except the last one.
Help? A little context? Where are these from?
1,向前(后)走一步 Forward (backward) one step
2,弯腰 Stoop
3,腰挺直 Back straight
4,像我这样做(动作) Follow me, Copy me, Do as I do, Follow my moves
(You need to choose one based on context)