Jarheads! Pffft!
As important as it was, I always dreaded the measuring of range because the PT always forced it farther than I was ready to go.
Walk before running.
A good walk allows similar mechanics and cardio with much less stress on the real and replaced joints.
Just a suggestion on something I mentioned to my PT. As an umpire, our movements are not always forward and reverse. we move laterally, sidling and cross-over steps, a lot. When I returned after my first replacement, I got hung up on a clump of dirt/mud and it was very painful.
I mentioned it to the PT after my second replacement and he had me do a few things that helped me become comfortable with lateral movement.
Good luck.