... The fi ndings indicated there was no signifi cant diff erence in performance for any of the measures using only mental practice. This fi nding does not agree with previous fi ndings in the current literature or any theory about the contribution of mental practice to motor learning ( Richardson, 1967a( Richardson, , 1967bFeltz & Landers, 1983 ;Denis, 1985 ;Grouios, 1992 ;Driskell, et al ., 1994 ;Wulf, et al ., 1995 ;Millard, et al ., 2001, Morris, Spittle, & Watt, 2005. However, it was unclear in previous studies if there was any control of the amount of physical practice by the mental practice groups ( Stebbins, 1968 ;Ryan & Simons, 1981 ;Zecker, 1982 ;Hird, et al ., 1991 ;Grouios, 1992 ;Blair, et al ., 1993 ;Overdorf, et al ., 2004 ;Brouziyne & Molinaro, 2005 ;Cahn, 2008 ;Tousaint & Blandin, 2010 ). ...