Hi CTun120,
Thanks for writing in. Sucks about the sprain. Only 6weeks out from this, 2weeks of which were still under load, is relatively fresh. If you can stairmachine at this point then it seems an otherwise rapid recovery is inevitable, assuming no major set-backs happen. Stairmachine sounds like the most tolerated and most similar to rucking and running and what would be my suggestion for modality to aim for. That and using the elliptical for fast leg speed and running-like body position; doing so might help you transition to actual running. Otherwise, time will need to pass until the foot is ready for the rigors of running, and you should let the foot tell you when it’s ready.
As time goes on perhaps treadmill jogging and short bouts of running can blend with stairmachine duration to sum total a workout’s duration. Again, you can’t force the comfort, but can slowly bring impact back into your volume.
All the best,
-Seth