Stand facing a wall with one foot forward and one foot back, both pointing straight ahead. Keep your back leg straight and your back heel pressed flat into the floor, then lean your hips toward the wall until you feel a stretch up the back of your lower leg. Keep your back foot fully planted throughout — if your heel lifts, you've stepped too far back or leaned in too hard. Hold with steady, even pressure rather than bouncing into it, then switch legs to stretch the other side. A slight bend in your back knee shifts the stretch lower, closer to your Achilles itself, if you want to feel it in a different spot.