Some problem about animation data from Motionbuilder to Maya

Hi,guys.Now I have some questions to consult you. my compony is using MotionBuilder to handle with motion capture data, then export it to Maya. Some body part like elbow and knee, their three rotate axis have animation data, while in Maya, should only one rotate axis have animation data. I use script can make only one rotate axis have animation data, but for some state, I cannot solve this problem.
Now I want to know if have method that let elbow joint or knee joint only have one rotate axis that have animation data.Like elbow joint “rotateY” have animation data, while “rotateX” and “rotateZ” do not have animation data. Using method like lock “rotateX” and “rotateZ” rotate axis, and so on?
Expecting to hear from you as soon as possible.
My English is not good, sorry for it. Thank you, guys.