When I was studying yoga in the beginning, one thing that I could never remember was this; is a forward fold an extension or flexion of the spine, and the opposite with a backbend.
So I don’t forget:
- Flexion decreases the angle between two body parts
- Extension increases the angle
Therefore, a Backbend is an Extension and Forward Fold is Flexion.
Even though we think of the spine as the back of our body, it is in fact the front of the body that is extending when performing a backbend.
Yoga by Mārk 