Effects of postural and cognitive difficulty levels on the standing of healthy young males on an unstable platform

Abstract

Standing on an unstable platform requires continuous effort of the neuro-musculoskeletal system. The aim of the present study is to evaluate the ability to remain standing on an unstable platform at different levels of postural and cognitive difficulty. Healthy young males stood in the sagittal plane on an unstable platform supported by a pair of springs with modifiable stiffness. The balance test also assessed different levels of vision and cognitive function. Linear and nonlinear metrics of standing, based on motion captured kinematic data, were assessed to analyze the stability of standing. Results showed that vision plays a significant role in maintaining balance in terms of linear metrics. Elimination of visual feedback changed the direction of body sway and increased standing instability. Placement of low stiffness springs led to unstable standing. The cognitive dual task, however, had no effect on the stability metrics and merely could be revealed in the simplest test condition. Standing on an unstable platform was closely related to visual feedback and decreasing the spring stiffness significantly reduced stability. The roles of cognitive involvement were subdued by increasing the postural difficulty in standing on an unstable platform.

Correlation between the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Scores and the Stability Metrics in Patients with Knee Osteoarthritis

“…The support condition also increased the variability of the AP CoP. Ivanenko et al (1997) showed the difficulty of standing on an unstable platform even for the healthy controls [16,30,31] . The difficulty in standing for such a condition has originated from the narrow horizontal beam of the base of support where the semi-ellipses of the platform contact the ground.…”

Quantitative assessment of the level of instability of a single-plane balance platform

“…From a biomechanical perspective, it has not yet been analysed in detail which mechanisms of postural stability are dominant when standing on an unstable platform. Critically assessing, the level of imbalance created by these platforms should be high due to the dynamically changing body mass center and support area [8]. They differ in that those different approaches are used to disrupt stability, as well as activating different strategies to balance.…”