In backstroke, the arms contribute most of the forward movement. The arm stroke consists of two main parts: the power phase (consisting of three separate parts) and the recovery. The arms alternate so that always one arm is underwater while the other arm is recovering. One complete arm turn is considered one cycle. From the initial position, one arm sinks slightly under water and turns the palm outward to start the catch phase (first part of the power phase). The hand enters downward (pinkie finger first) then pulling out at a 45 degree angle, catching the water.