Influence of diabetes progression on dynamic recruitment patterns of muscular fibers analyzed through high density electromyography

Author(s)

Marco Kenji Butugan

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD)
• Defense date: 2014-04-29

Examining board members

Isabel de Camargo Neves Sacco; Amelia Pasqual Marques; Adson Ferreira da Rocha

• Advisor: Isabel de Camargo Neves Sacco

Abstract

This study aimed at investigating the influence of different stages of diabetic neuropathy in the muscle fiber conduction velocities estimated in four lower limb mucles during isometric maximal voluntary contraction using surface electromyography. Eighty-five adults were studied: 16 non-diabetic individuals and 69 diabetic patients classified into four neuropathy stages, defined by a fuzzy system: absent (n=26), mild (n=21), moderate (n=11) and severe (n=11). Average muscle fiber conduction velocities of gastrocnemius medialis, tibialis anterior, vastus lateralis and biceps femoris were assessed using linear array electrodes, and the studied groups were compared by ANOVAs (p < 0.05). Conduction velocities were significantly decreased in the moderate neuropathy group for the vastus lateralis compared to other groups (from 18 to 21% decrease), and were decreased in all diabetic groups for the tibialis anterior (from 15 to 20% from control group). Not only the distal anatomical localization of the muscle affects the conduction velocity, but also the proportion of muscle fiber type, where the tibialis anterior, with greater type I fiber proportion, is affected already at the absent group while the vastus lateralis with greater type II fiber proportion is affected in later stages of the disease. Generally, the muscles of the lower limb have different responsiveness to the effects of diabetes mellitus and neuropathy and show a reduction in the conduction velocity as the neuropathy progresses (AU)

• FAPESP's process: 11/15770-0 - Influence of diabetes progression on dynamic recruitment patterns of muscular fibers analyzed through high density electromyography
• Grantee: Marco Kenji Butugan
• Support Opportunities: Scholarships in Brazil - Master