Award Date


Degree Type


Degree Name

Master of Science (MS)


Kinesiology and Nutrition Sciences

First Committee Member

Gaby Wulf

Second Committee Member

James Navalta

Third Committee Member

Brach Poston

Fourth Committee Member

Szu-Ping Lee

Number of Pages



According to the OPTIMAL theory of motor learning (Wulf & Lewthwaite, 2016), autonomy support (AS), enhanced expectancies (EE), and external focus (EF) of attention are key to effective motor performance and learning. AS allows individuals to exercise control, EE

provides performers with an increased sense of confidence, and EF directs attention to the intended movement effects. Previous research indicates that these factors individually and collectively can improve motor performance and learning in novices and experienced performers. Few studies have used elite performers as participants. Purpose: To determine whether skilled throwing performance can be enhanced by a successive implementation of AS, EE, and EF. Methods: Twenty-four healthy, elite female softball players (21.36 ± 1.58 yrs, 14.44 ± 2.75 yrs of softball experience) threw softballs at a bullseye target (10m). Athletes were randomly assigned to two groups: 1) an experimental group provided with all three OPTIMAL factors and 2) a control group. Specifically, the optimized group was given choice of softballs (AS), was given a liberal definition of success (EE), and was instructed to focus on the bullseye (EF). Throwing accuracy was assessed during five 12-throw blocks: a baseline block; the three middle blocks with factor introduction; a transfer test block (12m). Results: No significant group difference in throwing accuracy were seen for baseline, p = 0.551, blocks 2-4, p = 0.798, or transfer test, p = 0.557. No significant group difference was seen in self-efficacy scores for baseline, p = 0.145, blocks 2-4, p = 0.472, or transfer test, p = 0.392. Conclusion: Throwing performance, as well as reported self-efficacy scores, did not change across the blocks with the successive implementation of the OPTIMAL factors. Possible reasons for the lack of group differences include: Both groups preferred to throw with the same ball (AS), participants met the criterion for success more than 75% of the time (EE), and the participants could have already been focusing externally (EF). Furthermore, a single practice session might not be long enough to improve throwing performance, likely as a result of years of repetitions under the same motor patterns. These highly skilled athletes might already have a high level of self-efficacy preexisting from their softball careers, and that self-efficacy might not easily change from a single practice session. Highly skilled athletes take years to improve their skills and might benefit from the addition of appropriate PTIMAL factor manipulations over a longer time period (e.g., an entire sporting season).


Autonomy support; Enhanced expectancies; External focus; OPTIMAL



File Format


File Size

1.2 MB

Degree Grantor

University of Nevada, Las Vegas




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