EMG patterns during running: Intra- and inter-individual variability.

Area of Science:

• Biomechanics
• Neuroscience
• Exercise Physiology

Background:

• Understanding the central nervous system's control of running is crucial.
• Defining normal electromyographic (EMG) patterns provides a baseline for gait analysis.

Purpose of the Study:

• To establish a normal profile of EMG activity during running gait.
• To investigate the neuromuscular control strategies employed during running.

Main Methods:

• Recorded rectified surface EMG signals from seven muscles in five healthy subjects running at 4.2 m/s.
• Utilized footswitch signals to correlate muscle activity with the stride cycle.
• Analyzed intra- and inter-individual variability in EMG profiles and peak activation times.

Main Results:

• Found minimal within-individual variation in EMG profiles and peak times across trials.
• Observed significant inter-individual differences in EMG profiles and peak times (P < 0.01).
• Identified two distinct muscle activation sequences: one during the stance phase and another during terminal swing.

Conclusions:

• Despite significant inter-individual variability, a common neuromuscular control strategy exists for running.
• Distinct muscle activation sequences during stance and terminal swing phases suggest coordinated neural control.
• No significant EMG activity was observed during the initial double support phase of the running gait.