LB runs forward and passes the ball to RB, who runs forward.
After the pass LB runs against LW, receives a ball and returns it.
Then LB moves behind the row.
RB, who has moved forward and has receives the ball from LB continues forward and returns the ball to the next player in the LB row.
After the pass RB runs against RW, receives a ball and returns it.
Then RB runs back behind the RB-row.
The exercise continues with LB moving forward.