Couch Stretch

Kneel facing away from a couch or bench with your back foot up against its base, shin resting vertically so the top of that foot points up. Your front foot plants flat on the floor in a lunge. Stay tall through your torso, brace your stomach lightly, and squeeze the glute on the back-leg side to tuck your pelvis under — that's what moves the stretch from your knee into your hip flexor and quad, where it belongs. Walk your front foot forward a little to go deeper, and keep your ribs stacked over your hips rather than leaning forward, which lets your lower back take over. If your knee doesn't like being loaded that hard, pad it or shorten the stance.