Lack of femur rotation during "calf inward"

I have a hard time getting much inward rotation when doing the "calf inward" exercise.  And it seems like any rotation I do get is from the knee down (i.e., nothing from the femur).  

What would be the minimum acceptable inward rotation here?  

Is there something I can do to help increase inward femur rotational ROM?

Hi Joe,

It really helps us to see a video. My advice for now is that at first you may not be able to match the degree of inward roatation that is shown in the videos. As your hips and ankles become more mobile, your position will naturally improve. 

I agree with what Everett said. Remember that flexibility is a process and will improve over time as you dedicate proper time and attention to making it better. Also, posting a video would be very helpful as Everett stated.

It happens the same to me. My right piriformis is extremely tight, so much that it continiously rotate my right leg externally and I walk like a duck  . I just try my best. In my opinion this is lack of internal rotation so Swivel Hips will probably help you.