Ready Position: Chest Expander held across the shoulders with body erect and with the feet slightly apart if desired.
Movement: Press out the expander until the arms are prefectly straight and in a line with the shoulders. The body may be bent forward in the endeavour to press out the strands, but must assume the erect position directly. Keep up the tension while going into the ready position.
This is one of the basic exercises for Chest Expander / Strand Pull Training. You can see how much force you need to press the handles apart. It is pretty good for increasing your Push Up repetitions.