Regulation of dynamic postural control to attend manual steadiness constraints

Author(s)

Teixeira, Luis Augusto ^[1] ; Serpa Coutinho, Joane de Figueiredo ^[1] ; Coelho, Daniel Boari ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Sch Phys Educ & Sport, Human Motor Syst Lab, Sao Paulo - Brazil

^[2] Fed Univ ABC, Biomed Engn, Sao Bernardo Do Campo, SP - Brazil

• Document type: Journal article
• Source: Journal of Neurophysiology; v. 120, n. 2, p. 693-702, AUG 2018.
• Web of Science Citations: 1

Abstract

In daily living activities, performance of spatially accurate manual movements in upright stance depends on postural stability. In the present investigation, we aimed to evaluate the effect of the required manual steadiness (task constraint) on the regulation of dynamic postural control. A single group of young participants (n = 20) were evaluated in the performance of a dual posturo-manual task of balancing on a platform oscillating in sinusoidal translations at 0.4-Hz (low) or 1-Hz (high) frequencies while stabilizing a cylinder on a handheld tray. Manual task constraint was manipulated by comparing the conditions of keeping the cylinder stationary on its flat or round side, corresponding to low and high manual task constraints, respectively. Results showed that in the low oscillation frequency the high manual task constraint led to lower oscillation amplitudes of the head, center of mass, and tray, in addition to higher relative phase values between ankle/hipshoulder oscillatory rotations and between center of mass/center of pressure-feet oscillations as compared with values observed in the low manual task constraint. Further analyses showed that the high manual task constraint also affected variables related to both postural (increased amplitudes of center of pressure oscillation) and manual (increased amplitude of shoulder rotations) task components in the high oscillation frequency. These results suggest that control of a dynamic posturo-manual task is modulated in distinct parameters to attend the required manual steadiness in a complex and flexible way. NEW \& NOTEWORTHY We evaluated dynamic postural control on a platform oscillating in sinusoidal translations at different frequencies while performing a manual task with low or high steadiness constraints. Results showed that high manual task constraint led to modulation of metric and coordination variables associated with greater postural stability. Our findings suggest that motor control is regulated in an integrative mode at the posturo-manual task level, with reciprocal inteiplay between the postural and manual components. (AU)

• FAPESP's process: 11/20265-3 - Central organization in generating anticipatory and reactive postural adjustments in the elderly
• Grantee: Luis Augusto Teixeira
• Support Opportunities: Regular Research Grants