The name, head-to-knee pose, describes the fact that if the body’s flexibility allows, the whole of the torso will fold over the outstretched leg, with the head touching the knee or going beyond the knee, depending on the individual body’s proportions. As a result, it is sometimes called head-beyond-the-knee pose.
The asymmetry of the pose means that as well as being a forward bend, it also provides a slight spinal twist. Head-to-knee pose B is a good pose for creating the flexibility needed to progress into seated forward bend, where both legs are straight. This variation provides a slightly deeper posture for stretching the hamstrings than head-to-knee forward bend A due to the elevation of the hips.
In addition to stretching the hamstrings, it is also said to stimulate the kidneys and liver. It benefits the digestive system by stretching both the ascending and descending colon. It may be helpful for those suffering with headaches, fatigue, or menstrual pains; however, it should be avoided by anyone suffering from asthma, digestive or lower back issues.
This variation may feel more uncomfortable than variation A due to the pressure of the heel. It can be modified by placing blankets under the buttocks, or under the knee of the outstretched leg if tight hamstrings or knee pain is an issue. For those with more flexibility, the hands can clasp the edges of the foot or one hand can clasp the opposite wrist around the sole of the foot, with the head moving onto the shin. An alternative is simply to do head-to-knee forward bend A if this feels too intense.