Torn quadriceps injury but the FAA had specific return to work requirements that might apply to the toran Achilles tendon. It was based on which aircraft you were flying and the s/e rudder pressure and duration requirements. I forget the exact numbers but it was specific - something like "63 lbs for 93 seconds." My understanding was that it was the time expected from an engine failure at V1 until some point in the clean up process?? AMAS/union medical advisors provided the specific numbers. Exceeded the requirements (see next paragraph re: first flight post recovery).

I did multiple different exercises (with PT approval...everything went through them!), squats, toe raises, inclined leg press, straight leg press, all as straight squats or with bent knees (various angles) doing ankle or knee flextion movements. First flight...and realized the brake pedal pressure was higher or at least a different angle. Barely able to release the parking brake. Very uncomfortable. Next time I'd add higher pressure events using more of the ball of my foot.

Knee did not like the pressure changes or staying at one angle for too long. Took about 10 ibuprofen a day to go from home >work >fly >hotel as well as frequent (every couple of minutes) changes to the angle of my knee.

Good luck.