Award Date


Degree Type


Degree Name

Doctor of Physical Therapy (DPT)


Physical Therapy

Advisor 1

Merrill Landers

First Committee Member

Merrill Landers

Second Committee Member

Kai Yu Ho

Third Committee Member

Kathryn Hausbeck Korgan

Number of Pages



Background: It has been reported individuals typically perform well on a task when enhanced expectancy was provided prior to task performance. It has also been reported people with Parkinson’s disease (PD) are especially susceptible to pre-task placebo cuing and suggestion. Evidence of this susceptibility has been previously demonstrated through brain imaging studies and with demonstration by individuals with PD improved balance performance.

Objective: This study was designed to further previous studies’ results for improved task performance with enhanced expectancy. The purpose of this study was to investigate if the pre-task verbal delivery of enhanced expectancy, decreased expectancy and no expectancy would affect the performance of individuals with PD during balance tasks.

Design: Two groups of individuals (individuals with PD and age/gender matched healthy adults) were randomly assigned to perform three separate balance tasks. One of three randomly assigned expectancies (enhanced, decreased or neutral) was verbally delivered by a researcher to the individual prior to each balance task performance.

Methods: Forty-nine subjects (20 females and 29 males, Age 72 ± 7 years) participated, including 24 patients with idiopathic PD (9 females, Age 73 ± 6.58; 15 males, Age 73 ± 7.21) and 25 healthy controls (11 females, Age 70.27 ± 4.69; 14 males, Age 71.86 ± 8.90) without PD. All participants were asked to perform three balance tasks while three randomly assigned verbal cues were given prior to each task. Non-parametric, repeated measures Friedman’s tests were conducted to compare 1) the effects of verbal cues on balance (Limits of Stability, Maze Control and Random Control) for the PD group and the age-and-gender matched control group, and 2) the converted z scores of the three balance tasks among the three verbal conditions in combined PD and control groups. Alpha was set at 0.05.

Results: Friedman’s ANOVAs showed that the usage of enhanced expectancy, decreased expectancy and no expectancy demonstrated no significant difference on balance performance for each of three separate balance tasks or for individuals with PD or without PD (ps≥.05).

Discussion and conclusion: Although the present research study did not present significant results of the main finding, different expectancy instructions prior to a balance task differently change balance performance, this study did imply for continued future research in pre-task expectancy.


Balance; Enhanced expectancy; Equilibrium (Physiology); Parkinson’s disease


Applied Statistics | Physical Therapy | Rehabilitation and Therapy | Statistics and Probability

File Format


File Size

797 Kb

Degree Grantor

University of Nevada, Las Vegas




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