Respiratory phase and precision motor control: Distinguishing action selection from execution error

Abstract

Respiratory timing can accompany a manual action without determining its execution accuracy. Interpretation requires distinctions among action selection, force steadiness, target error and endurance. In this article eight human performance experiments were appraised by task, respiratory manipulation, endpoint, source accessibility and inferential limitation. Neural and physiological studies supplied mechanistic context. Conditional-expectation identities and an additive periodic-error model were used to examine phase selection and interval averaging. Coordination was associated with improved tracking precision and inspiratory handgrip endurance in specific tasks, whereas other experiments identified amplitude-related force fluctuations or frequency-related changes in response speed. These findings address different outcomes and do not establish a universal phase advantage. Evidence strength is restricted by small or selective samples, abstract-only access for several reports and inconsistent statistical reporting in one experiment. The calculation shows that averaging over complete cycles removes a periodic contribution from signed bias while preserving its contribution to mean-square error. Partial-cycle results depend on duration, onset phase, perturbation lag and constant bias. The contribution is an outcome-specific interpretation of respiratory exposure during movement execution, rather than a new mathematical theorem or a validated breathing intervention. Prespecified contrasts involving support, sensory timing, ventilation and analysis duration can distinguish competing explanations of respiratory associations in precision kinesiology.