Perform Baddha Konasana. Exhale and lower your back torso toward the floor, first leaning on your hands. Once you are leaning back on your forearms, use your hands to spread the back of your pelvis and release your lower back and upper buttocks through your tailbone. Bring your torso all the way to the floor, supporting your head and neck on a blanket roll or bolster if needed.
With your hands grip your topmost thighs and rotate your inner thighs externally, pressing your outer thighs away from the sides of your torso. Next slide your hands along your outer thighs from the hips toward the knees and widen your outer knees away from your hips. Then slide your hands down along your inner thighs, from the knees to the groins. Imagine that your inner groins are sinking into your pelvis. Push your hip points together, so that while the back pelvis widens, the front pelvis narrows. Lay your arms on the floor, angled at about 45 degrees from the sides of your torso, palms up.
The natural tendency in this pose is to push the knees toward the floor in the belief that this will increase the stretch of the inner thighs and groins. But especially if your groins are tight, pushing the knees down will have just the opposite of the intended effect: The groins will harden, as will your belly and lower back. Instead, imagine that your knees are floating up toward the ceiling and continue settling your groins deep into your pelvis. As your groins drop toward the floor, so will your knees.
To start, stay in this pose for one minute. Gradually extend your stay anywhere from five to 10 minutes. To come out, use your hands to press your thighs together, then roll over onto one side and push yourself away from the floor, head trailing the torso.