I'm used to this. It's not possible to sit without blanket on the hard ground, but it is very comfortable for me. The knees came down by enduring practice.
In the beginning i needed some soft stuff under the feet. But now they are used to this position.
Metta, Karuna, Mudita, Upekha
*** May these efforts be helpful.
Djang chub sem chog rinpoche, ma kye pa nam kye gyur chig. Kye pa nyam pa me pa yang, gong nä gong du phel war sho._()_**