Muscles Used in the Backstroke. Even though you're swimming on your back, you use your abdominals in addition to the muscles of your back -- the latissimus dorsi and spinus erectors -- to support you as you flow through the water during the backstroke.
The average distance for a pitching wedge is 130 to 135 yards; for a sand wedge 115 to 120 yards; and for lob wedges 75 to 95 yards.
The original Knickerbocker Rules did not specify the pitching distance explicitly. By the time major league baseball began in the 1870s, the pitcher was compelled to pitch from within a box whose front edge was 45 feet from the point of home plate.