When I was a child I did ballet, tap and acrobats! I could then lie on my tum and touch the back of my head with my feet
But have since found out that it indicated a too bendy spine as a result of which a xray I had done a few years ago showed I had some fused vertebrae at the lower end which causes sciatica from time to time. I can still touch my toes, or put my hands flat on the floor, but my friend says thats because I have short legs