The body is a sophisticated vehicle for the soul. We may not ever feel the need to stretch ourselves into strange positions, but we certainly ought to maintain our body in the healthiest condition that we can. As with martial arts practices, the physical part of yoga, the asanas or postures at once stretch and strengthen all of the muscles while purifying them of toxins.
These asanas are as artistic as they are scientific and medicinal. Please be cautious when attempting any pose. If it hurts, back out of it slowly, and continue breathing softly and deeply. It may help to compare pain with landmines in terms of how to deal with them. Approach carefully. Disarm skillfully. Continue softly, attentive to other landmines. A far more common approach would be to avoid the pain altogether, in which case the landmines persist, ignored, with occasional accidental explosions. Each person must decide whether to ignore or seek and disarm her landmines