EEG time-frequency analysis provides arguments for arm swing support in human gait control

Area of Science:

• Neuroscience
• Human Motor Control
• Gait Analysis

Background:

• Human gait relies on coordinated limb movements, with arm swing enhancing efficiency.
• The Supplementary Motor Area (SMA) is known to be involved in multi-limb coordination.
• The SMA's anatomical position suggests a role in controlling gait.

Purpose of the Study:

• To investigate the functional involvement of the SMA in gait-related arm swing.
• To explore the neural mechanisms underlying the coordination of arm and leg movements during walking.

Main Methods:

• Ambulant electroencephalography (EEG) was used to record brain activity in 20 healthy older adults.
• Participants walked with and without arm swing.
• Event Related Spectral Perturbation (ERSP) analysis assessed power changes in the EEG frequency spectrum over sensorimotor regions, including the SMA.

Main Results:

• Walking with arm swing showed a distinct step-related pattern of Event Related Desynchronization (ERD) followed by Event Related Synchronization (ERS) over the SMA (electrode Fz).
• This pattern was altered when arm swing was absent, with reduced power changes over Fz.
• Specific ERD-ERS patterns were observed over other sensorimotor areas, reflecting leg movement coordination and its modulation by arm swing.

Conclusions:

• The observed ERD-ERS pattern over the SMA during walking with arm swing supports its contribution to integrated, cyclic, anti-phase movements of the upper and lower limbs.
• These findings suggest a cortical basis for the role of arm swing in supporting gait control.