The use of a single case design to investigate the effect of a pre-performance routine on the water polo penalty shot

The pre-performance routine (PPR) is proposed to assist the performance of closed skills by enhancing concentration (Crews and Boutcher, 1987) and the recall of optimal psychological and physiological states (Cohn, 1990). A multiple-baseline-across-individuals design was utilised to assess the effect of PPRs on water polo penalty shot performance. Three experienced male water polo players were assisted in designing a personalised multi-component PPR, which was rehearsed in accordance with a training program, and implemented prior to performing penalty shots in simulated trials. Mean performance scores increased for all players between pre and post intervention phases. A Split Middle analysis (White, 1974) further described performance trends and changes. Players 1 and 2 reversed negative baseline trends of -1.071 and -1.031 to positive post intervention trends of +1.011 and +1.011, producing respective positive changes in slope of +1.08 and +1.042. Player 3's baseline trend of +1.008 was reversed post intervention to -1.004, causing a negative change in slope of -1.012. Respective ratios of 1.38, 1.36 and 1.20, suggest a positive change in trend level immediately following PPR introduction. Binomial tests revealed improvements in all participant performances between stages (p<0.001). Results are reviewed in light of previous research and the utilisation of single-subject designs is discussed.