How to put your heels on the floor in Adho mukha shvanasana (or down dog asana)?
It's obvious in order to put the heels on the floor you need to engage and stretch the back surface of your leg. But there is also another way.
First you need a good warm up using Suryanamaskar (I wrote about it in my last post).
Second — you should fix in adho mukha shvanasana and try to put the heels on the floor, one after one (as shown on the photo below).
You can also help your foot with the other foot to do that.
Good luck! Practise every day and remember:
"Yoga is the best way to be young and to improve both mind and body."