Say you're surfing. You've seen the pose, knees bent, one foot in front of the other, blond tresses blowing in the sea breeze. The waves are changing, or you're at the end of a run, and you need to change the direction of the board, what do you do? You do the switchfoot, moving the position of the feet on the board to change the direction you're going.
To turn around. To completely change direction. To Switchfoot.
BTW, go buy their new album.