Interaction between interpersonal and postural coordination during frequency scaled rhythmic sway: The role of dance expertise

• Light fingertip touch evokes interpersonal synchrony during rhythmic sway.
• We asked how interpersonal interact with postural dynamics in frequency paced sway.
• Haptically evoked interpersonal synchrony did not alter the ankle–hip coordination.
• Ankle–hip coupling was lost at high sway frequencies in non dancers.
• Non-dancers did not entrain with touch at high sway frequencies.

Light fingertip touch between partners swaying rhythmically side by side evokes interpersonal synchrony. In non-dancers and dancers swaying to a metronome, we examined the effects of frequency scaling and touch between the partners on both postural (ankle–hip) and inter-personal coordination. In both groups, touch did not interfere with the ankle–hip coordination. In non-dancers but not dancers, increasing frequency resulted in a loss of the ankle–hip coupling that was accompanied by a reduction of the touch mediated interpersonal synchrony. It is suggested that the effect of touch on interpersonal synchrony depends on the reliability of the haptic information sensed at the fingertip and assumes an in phase ankle–hip coupling. These findings have implications in clinical practice when using touch to help balance impaired individuals.