Sample Entropy-Based Surface Electromyographic Examination With a Linear Electrode Array in Survivors With Spinal...

Area of Science:

• Biomedical Engineering
• Neuroscience
• Rehabilitation Science

Background:

• Spinal cord injury (SCI) significantly alters neuromuscular function.
• Quantifying these changes is crucial for effective rehabilitation and motor recovery.
• Surface electromyography (sEMG) offers a non-invasive method to assess muscle activity.

Purpose of the Study:

• To evaluate the utility of sample entropy (SampEn) in analyzing sEMG signals for quantifying neuromuscular changes post-SCI.
• To compare SampEn values between individuals with SCI and healthy controls.
• To investigate the influence of electrode placement, specifically the innervation zone (IZ), on sEMG analysis.

Main Methods:

• sEMG signals were recorded from the biceps brachii during isometric elbow flexion in 13 SCI subjects and 13 controls.
• A linear electrode array was used to identify the representative channel and the IZ channel.
• SampEn analysis was applied to sEMG data, averaged across various force levels.

Main Results:

• SampEn values exhibited a significantly greater range in SCI subjects compared to controls at the group level.
• Individual SCI subjects displayed abnormal increases or decreases in SampEn.
• A significant difference in SampEn was observed between the representative channel and the IZ channel.

Conclusions:

• SampEn is a valuable quantitative indicator for detecting neuromuscular alterations following SCI.
• The innervation zone (IZ) plays a noteworthy role in sEMG signal interpretation.
• This approach may support the development of targeted rehabilitation interventions to improve motor function after SCI.