There are three main variations of head-to-knee pose. Head-to-knee pose A is the variation in which the foot of the bent leg rests toward the top of the extended inner thigh. In head-to-knee pose B, the foot is tucked underneath the body so that the heel is near the perineum. This variation stimulates the pelvic floor area. The most advanced variation is head-to-knee pose C, in which the foot is placed against the extended leg in such a way that the toes are pointed down and tucked under.
All variations of head-to-knee pose are forward bends, hence they stretch the back of the body, offering a release to the hamstrings of the extended leg. They also stretch the shoulders and groin.
The way that the body folds forward in this posture is thought to stimulate the kidneys and the liver, as well as improve digestion. It is said that this posture can also help relieve symptoms for those experiencing menopause.