ABSTRACT
Purpose: This research study was conducted to determine the effects of psychological stress and relaxation on quadriceps muscle strength. It was anticipated that clinical implications could be made regarding patient performance as affected by individual experiences. The researchers hypothesized that stress would elicit an increased strength of contraction, while relaxation would have the opposite effect.
Methods: Thirty-two University of Scranton students, aged 18-22, volunteered for the study. Testing was administered on two separate occasions one week apart. The testing procedure consisted of a pre- and post-test of quadriceps muscle strength using the BIODEX System 2 isokinetic program. During each session the subjects received either mental stress or relaxation stimuli as an intervention. The stressor was a 12-minute, progressively difficult mental math task. The relaxor, a 12-minute audio cassette, consisted of soothing music and subliminal relaxation messages presented while subjects rested in a dark secluded room. Heart rate and blood pressure were monitored at the start of each session and following the intervention.
Results: Student’s t-tests were used to analyze differences between pre- and post-test data. No significant strength changes were found for either intervention at an alpha level of .05 (p=.438 for stress, .103 for relaxation). However, trends were seen in the directions hypothesized by the examiners. Significance was found for increased heart rate after stress (p=.035).
Conclusion: Although individual trends
were noted, it was not possible to make a generalized conclusion due to
varying coping mechanisms in humans. The researchers emphasize that it
remains clinically important to recognize and address individual reactions
to psychological stimuli during treatment.