Flip seat all way back. Stand facing bar with supporting foot slightly forward under, or near apparatus. Grasp handle bars for support. Place top of other foot back on top edge of shin pad.
Squat down with back straight while straightening hip of rear leg by pushing hips forward. Hold stretch. Repeat with opposite side.
Keep foot away from fully extended hip to keep emphasis on Iliopsoas. See Lever Quadriceps Stretch for similar movement.