Gait initiation and falls: exploration of motor-related cortical potentials and anticipatory postural adjustments

Abstract: Ageing seems to affect the gait initiation phase thus increasing the risk of falls. Electroencephalography and force platforms were used to simultaneously measure motor cortical activity and vertical ground reaction force variations under both feet during gait initiation under single-task and dual-task conditions. Supporting summary: Gait initiation is a risky activity for older adults (Polcyn et al., 1998). Gait initiation is made possible by the variation of muscle-induced vertical ground reaction forces (VGRF) under both feet. In addition, motor imagery studies have found an increased activity in the motor cortex during GI (e.g. Sahyoun, Floyer-Lea, Johansen-Berg & Matthews, 2004). However, those studies have overlooked older adults with a history of falling. The current study used electroencephalography (EEG) and two force platforms to measure EEG activity and VRGF under both feet during the physical execution of the first step. Participants included 10 healthy older adults (aged 65 and above) and 10 age-matched older adults who have experienced at least one fall in the past year (fallers). Participants were required to stand still with two feet on separate force platforms and initiate gait. Results show no significant differences in EEG activity and patterns of VGRF in fallers in comparison to non-fallers. The discussion focuses on the possible implications in the risk of falls. Cau, N., Cimolin, V., Galli, M., Precilios, H., Tacchini, E., Santovito, C., & Capodaglio, P. (2014). Center of pressure displacements during gait initiation in individuals with obesity. Journal of Neuroengineering and Rehabilitation, 11(1), 82. Patchay, S., & Gahéry, Y. (2003). Effect of asymmetrical limb loading on early postural adjustments associated with gait initiation in young healthy adults. Gait & Posture, 18(1), 85-94. Sahyoun, C., Floyer-Lea, A., Johansen-Berg, H., & Matthews, P. M. (2004). Towards an understanding of gait control: brain activation during the anticipation, preparation and execution of foot movements. Neuroimage, 21(2), 568-575