I don't animate in Maya, but the easiest solution would probably be to create new keyframes in the problem spots and manually move the leg or whatever is causing the problem out of the way. It's common issue in all animation programs, the program just moves the objects in straight lines using math.. it doesn't know how it's supposed to move.
Or just modify the motion curves. See here for an introduction: https://www.3dtutorialzone.com/tutorial?id=96
Imagination is more important than knowledge.