Cortical Activity Measured with EEG during Stepping on a Recumbent Stepper

ABSTRACT

OBJECTIVE: Recent neuroimaging studies have shown a strong involvement of the cortex as well as brainstem locomotor center in locomotion. In the present study, cortical activity during constant stepping was investigated using electroencephalography (EEG). METHOD: Five healthy volunteers participated in this study. Sixty-four channel EEG was measured for 10 min while the participants performed constant stepping on a cadence of 100 rpm (50 cycles per 1 min) using a recumbent stepper. Surface electromyography (EMG) was also measured at the bilateral vastus medialis muscles. Each stepping cycle was epoched from the onset of EMG signal of the right vastus medialis muscle. Averaged event-related potentials (ERP) and event-related spectral perturbations (ERSP) of all subjects were calculated at all EEG channels. RESULTS: Periodic change of ERP was centered on the CZ and FPZ electrodes. While ERP at the CZ started to increase at 200 and 800 ms, ERP at the FPZ started to increase at -50 and 600 ms. ERSP was remarkable at the CZ during stepping cycles. According to the stepping cycle, power increases were pronounced at low-gamma frequency band and also observed at beta band. CONCLUSION: This study showed cortical activity during constant stepping using EEG in healthy participants. Periodic cortical activities were remarkable at the sensorimotor cortex area, and precedent activities were observed at the prefrontal area. EEG measurement during stepping on a recumbent stepper may be a valuable tool in investigating cortical activates related to walking in patients with gait disorders.