Now, to counter the strength of the external rotators, bring the inner edges of your feet together and press the base of your big toes and your inner heels into the wall. At the same time, press your inner thighs quite firmly toward the floor and, with less force, toward each other. All these actions engage the various internal rotators. Hold this position until your muscles start to fatigue—at first, this may take only a few seconds; eventually, you may build up to several minutes.
Now bring your awareness to your right leg. Press your right inner thigh toward the wall as you straighten your knee, resisting the tendency of the outer right hamstring to pull your leg into external rotation. Focus more on the rotation of your leg than on pulling your right foot toward you; when you're stretching your hamstrings to the max, it becomes nearly impossible to adjust your leg's rotation.
Stand and Deliver
Vrksasana (Tree Pose) is a one-legged balance that also challenges your internal rotators. After you lift your right foot to bring the sole to your inner left thigh, check the alignment of your torso. Are your navel and breastbone facing in the same direction as your left toes and knee? Or has your trunk rotated to the right? If so, the internal rotators of your left hip are falling down on the job. To help train them, practice with your left heel near or against a wall and your shoulders and buttocks lightly touching the wall. As you turn your right knee out, keep both buttocks evenly against the wall. You can apply the same techniques in the even more challenging Uttitha Hasta Padangusthasana II (Extended Hand-to-Big-Toe Pose II).
It's also important to internally rotate when you do inversions and seated forward bends. Again, the goal is to have your knees point straight ahead (up toward the ceiling, in seated forward bends), so your legs are neither externally nor internally rotated.
The internal rotators should also be integrated into backbending. To do this in poses like Setu Bandha Sarvangasana and Urdhva Dhanurasana (Upward Bow Pose), make sure your feet are parallel rather than turned out. Then, as you lift into the pose, press weight into the big toe mound and inner heel of each foot. It's fine to use the outer hamstrings and the buttocks muscles to help you extend your hips, but don't let them overwhelm the internally rotating hip extensors. Engage your inner hamstrings by pulling from the back of your knee toward the back of your hip and by lifting the outer thighs faster than the inner thighs. In these backbends, always be aware of your feet: If more weight shifts onto the outer edges of your feet, you're externally rotating—and increasing the likelihood of compressing your lower back.