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.
Although the new pitching distance is mandatory beginning with the 2010-11 school year, NFHS-member state high school associations may adopt the 43-feet distance in 2009-10, if desired. After at least 10 years of debate by committee members, the NFHS has extended the fast-pitch pitching distance to 43 feet.