Impact of Attentional Loading and Task Constraints on Postural Control of Healthy Older Adults

Background

Postural control, also referred to as balance or stability, is an integral aspect of the most voluntary actions (Winter, Patla, & Frank, 1990). Various executive processes, such as feedback based control and feedforward/open-loop control systems, as well as neuromuscular synergies contribute to the ability to generate actions that prevent humans from falling (e.g., when standing still on a moving bus). According to Newell’s model of constraints (1986), several related factors contribute to the ability to maintain stance. Some of them pertain to individual characteristics of structural or functional nature, whereas others relate to environmental as well as task constraints. In the context of postural control, structural constraints pertain to the anatomy of the human body such as weight, height, or size of base of support. On the other hand, functional constraints pertain to behavioral aspects of movement production such status of perceptuo-motor system or cognitive functioning. Environmental constraints include variables such as surface type (e.g., compliant versus non-compliant), or any other factors within the environment that may impact our actions. Meanwhile, task constraints pertain specifically to the requirements of the activity being performed, and in the case of the present research, the ability to maintain stance when presented with another cognitive task or when balancing without attentional interference.