Vigorous physical activity enhances intermuscular coordination between ankle muscles during gait

Area of Science:

• Neurology
• Biomechanics
• Exercise Physiology

Background:

• Intermuscular coordination (IMC) synchronizes muscle activity, crucial for movement.
• The precise impact of physical activity levels on IMC, particularly during gait, is not fully understood.
• Investigating IMC differences based on physical activity can reveal insights into neuromuscular adaptation.

Purpose of the Study:

• To determine if intermuscular coordination (IMC) in ankle muscles during gait differs between individuals with high and low IMC.
• To examine the relationship between physical activity levels and IMC in young adults.
• To assess the influence of weekly vigorous activity engagement on ankle muscle coordination.

Main Methods:

• Surface electromyography (EMG) recorded activity of tibialis anterior, soleus, and medial gastrocnemius during walking.
• Causal empirical mode decomposition identified muscle coordination patterns.
• Cross-approximate entropy (XApEn) quantified coordination between muscle pairs.
• K-means clustering categorized participants into high and low IMC groups.

Main Results:

• A significantly higher proportion of physically active individuals were in the high IMC group (83%) compared to the low IMC group (23%).
• Participants in the high IMC group reported greater weekly vigorous activity (240 min) than those in the low IMC group (0 min).
• Weekly vigorous activity showed a significant moderate correlation with IMC between antagonistic ankle muscles.

Conclusions:

• Physical activity demonstrably enhances intermuscular coordination of ankle muscles during gait.
• Vigorous physical activity plays a critical role in improving neuromuscular function.
• Regular exercise may counteract detrimental effects of sedentary behavior on the neuromuscular system.