- Lay on the floor
Straighten your legs
- .. but do not lock them.
- Arms by your sides
- Lift your legs to 180 degrees
You can let them fall, controlled, back over your head to touch the floor.
To avoid arching or tensing my back I tend to bend my legs and use momentum to get my knees up and over my midpoint. This is a bad habit because of general poor strength/flexibility and generally too much tension.