Muscle Synergy Alteration of Human During Walking With Lower Limb Exoskeleton

Area of Science:

• Biomechanics
• Neuroscience
• Robotics

Background:

• Muscle synergy is the brain's strategy for coordinating muscles during movement.
• Understanding how exoskeletons affect muscle coordination is crucial for rehabilitation and assistive technology.
• Previous research has not fully explored the impact of exoskeletons on inherent muscle synergy during walking.

Purpose of the Study:

• To investigate the changes in muscle synergy during normal walking with and without lower-limb exoskeletons.
• To analyze the electromyography (EMG) data for specific leg muscles to quantify synergy alterations.
• To determine if exoskeleton use significantly modifies the natural muscle coordination patterns.

Main Methods:

• Recruited 17 able-bodied subjects to perform walking tasks.
• Collected electromyography (EMG) signals from eight key leg muscles: tibialis anterior (TA), soleus (SOL), lateral gastrocnemius (GAS), vastus medialis oblique (VMO), vastus lateralis oblique (VLO), biceps femoris (BICE), semitendinosus (SEMI), and rectus femoris (RECT).
• Analyzed EMG data to compute and compare muscle synergy patterns between walking with and without exoskeletons.

Main Results:

• Quantitative analysis revealed that mean muscle synergy changed significantly when subjects wore exoskeletons.
• Statistically significant differences were observed in sub-patterns of muscle synergies between the exoskeleton and non-exoskeleton conditions.
• The study identified specific alterations in muscle coordination due to exoskeleton use.

Conclusions:

• Lower-limb exoskeleton use alters inherent muscle synergy during normal walking.
• Exoskeletons modify the neural control strategies for locomotion.
• These findings have implications for the design and application of exoskeletons in human movement assistance and rehabilitation.