Stand on one leg, holding something for balance if you need it. Bend your other knee and grab that foot or ankle behind you, pulling your heel toward your glute until you feel a stretch down the front of your thigh. Keep your knees close together and your hips pushed slightly forward rather than arching your lower back to add range — that arch just moves the stretch off your quad and onto your spine. Stand tall through your chest instead of hunching forward to reach your foot. This standing version is the default; if balance is the limiting factor, the lying or prone versions let you skip that problem entirely.