Lay on your back and bend both knees.
Drop stretching knee inwards, towards midline while keeping pelvis / waist in contact with the mat.
Place opposite foot on top of knee and apply gentle pressure, pushing knee towards ground; enough pressure to feel a stretch without significant discomfort or pain, while still maintaining the pelvis / waist against the surface that mat as much as possible.
Hold stretch for 1 min, then switch legs and repeat, for a total of 5 reps per leg, totaling 5 mins per leg. Perform 1 – 2 times per day, or as recommended by your MD or PT.