Through my own study and practice of yoga, I have come to understand how closely linked Indian classical dance is with yoga. Many of the postures, mudras and movements find their roots in asanas and pranayama. The preparation is not unlike the niyama preparation in Hatha Yoga. Most dances relate stories of the Divine such as the romance of Radha and Krishna. In some cases, the dance is the expression of the Divine, the Shiva Tandava being a famous example. These dance forms link back to Bhakti Yoga, perhaps the most prevalent practice in India.
I came across this story in the Hindu of a French lady who has conducted intense research on the links between yoga and Indian dance. Her study of Indian culture is very impressive. She has developed a practice called Yoga Dance Therapy that capitalizes on the overlap between dance and yoga. However, I am not clear on why one would need YDT. In the learning of Indian classical dance, one learns the yogic postures and mudras anyway. Indirectly, the dancer gets trained in yoga. Would knowing the exact relationship between the dance pose and the yogic aspect of it be a real benefit?