The backstroke is often compared to the front crawl because, overall, the movements are similar: kicking with the legs and alternating movements with the arms. But there are a few differences to be aware of, because in detail they are not exactly the same movements.
Here is what is required during a competition for the backstroke:
Except during the continuous execution of the turn, do not leave the backstroke position
Except during the first 15 metres at the start, at the turns and at the finish, do not be totally immersed during the swim
Start your turn immediately after going to the front position
Touch the wall during the turn
Do not stand on the bottom of the pool
Particularities of the backstroke:
The leg is stretched below the surface and then goes down, remaining stretched
Then the foot moves down a little more as the knee bends. The foot is well stretched at the point to be able to push upwards afterwards