The joints of the knees, ankles, and hips do so much to support us and carry us swiftly and with ease through our days, yet so often go without thanks or restoration. A yogic solution to this is to practice Supta Virasana.
Be aware that because the ankles, knees, and hips are such delicate and enormously-used joints, it is important to take great care when setting up this posture, while holding steady in this posture, and while exiting this posture. Alignment really matters in this pose.
Begin kneeling, with your knees in line with the greater trochanter of your hips (the top of the thigh bone, where it roots into your hip socket). Exhale to sit with your feet a bit wider than your hips and your inner arches hugging your outer hips, minding that your toes point straight back and do not sickle inward or outward.
If you have pain in your knees, or your hips do not rest on the floor, prop yourself up onto a blanket or block. Inhale to extend your spine and heart skyward and exhale to lean back, walking first your hands back, then perhaps coming down to your forearms and eventually to the back of your shoulders and head. Again, if you experience pain in your back, place props as appropriate. I like bolsters and blankets.
In the presence of the comfort or discomfort here, breathe in gratitude for your intelligent, strong and supportive body and hold.
After what feels like the right amount of time for you, inhale to come up to sit, lean forward onto your hands, and stretch your legs out behind you. Enjoy the flush of fluids into the joints of the knees and the lightness of spirit as a result of deeply opening your front body.