Virasana, when done daily and for a good length of time, can aid in curing a common condition known as flat feet.

Flat feet can be a major obstacle to an effective Iyengar yoga practice. This condition occurs when the inner arch of the foot collapses, and can lead to all sorts of complications, including unstable ankle support and lower back problems. From an Iyengar yoga perspective, when the inner arches of the feet are dropped it becomes difficult to activate the inner legs and consequently the whole inner body remains dull. Virasana is an essential pose in addressing this defect.
In BKS Iyengar’s classic text on yoga, Light On Yoga, each asana is presented visually and descriptively, as well as defining its effects. Virasana is a basic sitting pose where one sits on the buttocks, tops of the feet, and shins, with the hips positioned between the ankles (see featured image). It is a pose that, with more experienced practitioners, can be taken at the beginning of a practice, most commonly in the lying position, supta virasana, in order to soothe the thighs and quieten the mind before taking more vigorous poses. It can also be a useful pose to take at the end of a standing pose sequence, to ‘refresh’ the legs. At other times it can be taken as part of any sitting pose sequence, or used as a pose to take when doing different arm variations (parvatasana, gomukhasana, etc), or even as a sitting pose for pranayama.
In the ‘effects’ for virasana Iyengar states: ’The pose….. is good for flat feet. Due to the stretching of the ankles and the feet, proper arches will be formed. This, however, takes a long time and requires daily practice of the pose for a few minutes for several months.’ (Light On Yoga 5th ed. 2001 p. 93) That he states for the effects of this pose to be fully appreciated the pose needs to be done regularly over a long period of time is important. Recently I was in a class taken by one of Iyengars daughters, Sunita, and she explained that BKS would, when required, take the poses like one takes medicine. And for the poses to be taken medicinally they often need to be held for a good length of time, at least five to ten minutes.
To be able to take a pose daily for a good length of time on a daily (or at least regular) basis requires another ingredient. This ingredient is essential for anyone to maintain a regular practice generally and is elaborated on in more detail in this blog post. ‘Sraddha’ is translated as trust, and this is necessary in order to have faith in the process while the ‘long time’ plays itself out.
BKS Iyengar lists a number of other poses as being useful for curing flat feet, such as all the standing poses, head and shoulder stand, and numerous other poses (see Appendix II in Light on Yoga). Most of the other poses have a virasana component to them, so this could be considered the cornerstone pose for this condition. Thus virasana, mixed with consistency and faith, is the key in Iyengar yoga to treating flat feet.