Different cortical activation patterns during voluntary eccentric and concentric muscle contractions: an fMRI study

Area of Science:

• Neuroscience
• Motor Control
• Neuroimaging

Background:

• Concentric and eccentric muscle contractions exhibit unique neuromuscular and neurophysiologic properties.
• While research has detailed these features, neuroimaging studies comparing cortical activity during these contractions are limited.

Purpose of the Study:

• To investigate differences in cortical activity between eccentric and concentric muscle contractions of the wrist extensors using functional MRI (fMRI).

Main Methods:

• Fifteen healthy subjects performed wrist extensor contractions under both eccentric and concentric paradigms.
• Brain activity was scanned using fMRI, with BOLD signal intensities compared between contraction types in predefined regions of interest.

Main Results:

• Both contraction types activated numerous motor-related cortical areas, including the primary motor cortex, inferior parietal lobe, pre-SMA, anterior cingulate cortex, prefrontal cortex, and cerebellum.
• Eccentric contractions resulted in lower signal intensities in the right primary motor cortex and cerebellum compared to concentric contractions.
• Conversely, eccentric contractions showed higher signal intensities in other cortical areas compared to concentric contractions.

Conclusions:

• Eccentric and concentric muscle contractions induce distinct patterns of cortical activity.
• These differences may stem from varied neuro-motor processing strategies and increased cognitive demands during more challenging eccentric contractions.