Placebo and Nocebo Effects in Motor Performance: An Overview of Reviews

Area of Science:

• Neuroscience
• Psychology
• Sports Science

Background:

• The placebo and nocebo effects significantly influence health outcomes.
• Understanding their impact on motor performance is crucial for clinical applications.
• Existing literature reviews vary in quality and scope.

Purpose of the Study:

• To conduct an umbrella review assessing the effect size and literature quality of placebo and nocebo effects on motor performance.
• To synthesize findings on motor-related perceptive responses.

Main Methods:

• An umbrella review methodology was employed.
• Searched Medline, Embase, Lilacs, Cochrane, PROSPERO, and Open Access Theses and Dissertations.
• Included systematic reviews (with or without meta-analysis) of human participants investigating placebo/nocebo effects on motor performance and perception.

Main Results:

• 13 eligible reviews, encompassing 247 original studies, were identified.
• Placebo effects (SMD 0.09–0.93) and nocebo effects (SMD 0.37–1.20) on motor performance were reported.
• Most reviews exhibited poor methodological quality, with only two conducting GRADE assessments.

Conclusions:

• Placebo and nocebo effects on motor performance are variable.
• The poor quality of existing systematic reviews limits definitive conclusions.
• There is a critical need for rigorously conducted systematic reviews on these phenomena.