Wheel Pose is an advanced backbend and one of yoga's most challenging poses to do with the correct alignment. The key points are to keep the elbows and knees hugging inwards and the feet parrallel. The ideal alignment for a given yoga pose is not just a way to torture you, by the way. The idea is to have the bones of the body stacking neatly one on top of the other so that the skeleton is bearing your weight, not your muscles.

At age 79, 5′7″, 125 pounds, I do several exercises, Yoga, etc.–I’ll pass on this one!
At age 79, I’ll probaby be snoozing in my rocker! It’s great you have such an active, healthy lifestyle.