The influence of cognitive load on balance control during walking

Maintaining dynamic balance is essential during walking, with foot-placement playing a critical role. Situations requiring increased cognitive attention may impair an individual’s ability to actively control their balance. While dual-task studies have analyzed walking-while-talking conditions, few studies have focused on how cognitive loads impact balance control during steady-state walking and more difficult motor tasks, such as walking with foot-placement perturbations. Individuals recover from a loss of balance using an ankle or hip strategy, but how cognitive loads effect these recovery strategies remains unknown. The overall goal of this research was to investigate the influence of cognitive loads on balance control using two aims. The first aim assessed how individuals prioritize cognitive resources and control balance during steady-state walking with increasing cognitive loads. Aim 2 investigated how individuals prioritize cognitive resources to control their balance during dual-task walking while experiencing foot-placement perturbations. Fifteen young healthy adults performed a cognitive single-task condition (spelling-while-standing) and four treadmill walking conditions (no cognitive load, attentive listening, spelling short words backwards and spelling long words backwards), each performed during steady-state (Aim 1) and perturbed conditions (Aim 2). No specific task-prioritization instructions were given. During the perturbed trials, medial and lateral foot-placement perturbations were applied before heel-strike during random steps. Aim 1 showed that cognitive performance did not change between single- and dual-task conditions, but balance control decreased during the spelling dual-tasks. Aim 2 found that cognitive performance decreased between unperturbed and perturbed conditions. While balance control decreased during perturbed relative to unperturbed walking, the additional cognitive load had little effect during the perturbations. Lastly, the balance recovery strategy was unaffected by the addition of a cognitive load. The results from Aim 1 highlight that in steady-state walking, balance control decreases during treadmill walking with increased cognitive loads, but cognitive performance does not change, suggesting that participants prioritized cognitive performance over balance control. In contrast to steady-state walking, Aim 2 found that individuals prioritize their balance over cognitive task performance when faced with foot-placement perturbations. Overall, these results emphasize the flexibility of task-prioritization in young adults and provide a foundation for future studies analyzing neurologically impaired populations