Vibrotactile augmentation enhances late-phase control in sequential reaching without accuracy costs.

Introduction: Sequential goal-directed movements require the integration of advance planning and online control processes. However, the extent to which augmented sensory feedback influences these processes across multiple movement segments remains unclear. Vibrotactile and auditory feedback may enhance motor control by providing additional sensory information during movement execution, particularly in complex sequential tasks. Methods: Twenty-four neurotypical adults (mean age 27.04 ± 5.31 years) performed one-target and four two-target reaching tasks involving single- and bimanual movements with extension and reversal components. Participants completed the tasks under three sensory conditions: no feedback, auditory feedback, and vibrotactile feedback delivered at first target contact. Reaction time, movement time, spatial accuracy, and kinematic measures including peak velocity and time after peak velocity were analyzed using repeated-measures analyses of variance. Results: Reaction time was significantly influenced by both sensory condition and target task complexity, with faster movement initiation observed in the no-feedback condition and during less complex movement sequences. Sensory condition did not significantly affect overall movement time or spatial accuracy. However, vibrotactile feedback significantly reduced time after peak velocity during the second movement segment, indicating enhanced late-phase control without compromising accuracy. Target task complexity also significantly modulated kinematic control, particularly during bimanual reversal movements. Discussion: These findings demonstrate that vibrotactile feedback selectively enhances deceleration-related control during sequential reaching movements, supporting its role as an effective sensory augmentation strategy for improving movement efficiency in complex motor tasks. Such low-cost sensory interventions may have practical implications for enhancing motor performance in populations experiencing age-related or neurological declines in sensorimotor function.