Surface electromyography for characterizing neuromuscular changes in diabetic peripheral neuropathy

Distal symmetric polyneuropathy (DSP) is the most common diabetic neuropathy (75% of all diabetic neuropathies), potentially leading to plantar ulcers and lower limb amputation. Early detection of at-risk individuals is essential for timely intervention. This study aimed to evaluate different surface EMG (sEMG) parameters from isometric and dynamic exercises as biomarkers for early DSP detection and monitoring.

The study involved 61 participants (34 controls and 27 cases with low, moderate and high levels of severity). sEMG signals were recorded from four lower-limb muscles (tibialis anterior, medial gastrocnemius, extensor digitorum brevis, and flexor digitorum brevis) and characterized by their amplitude, frequency, complexity and shape.

Significant sEMG differences were found between controls and diabetic patients at low and moderate/high DSP risk, especially in the extensor digitorum and flexor digitorum muscles during isometric and dynamic exercises. Diabetic patients showed lower amplitude and complexity, with higher frequency, peakedness, and asymmetry.

Parameters like root mean square, sample entropy, and central shape distance effectively distinguished between groups, highlighting changes in motor unit recruitment and muscle quality. Dynamic and isometric exercises emphasized their complementary roles in assessing muscle function, supporting sEMG's potential as a non-invasive tool for monitoring neuromuscular changes in diabetes.