Reduced complexity of force and muscle activity during low level isometric contractions of the ankle in diabetic individuals

Author(s)

Suda, E. Y. ; Madeleine, P. ; Hirata, R. P. ; Samani, A. ; Kawamura, T. T. ; Sacco, I. C. N.

• Document type: Journal article
• Source: CLINICAL BIOMECHANICS; v. 42, p. 38-46, FEB 2017.
• Web of Science Citations: 7

Abstract

Background: This study evaluated the structure and amount of variability of surface electromyography (sEMG) patterns and ankle force data during low-level isometric contractions in diabetic subjects with different degrees of neuropathy. Methods: We assessed 10 control subjects and 38 diabetic patients, classified as absent, mild, moderate, or severe neuropathy, by a fuzzy system based on clinical variables. Multichannel sEMG (64-electrode matrix) of tibialis anterior and gastrocnemius medialis muscles were acquired during isometric contractions at 10%, 20%, and 30% of the maximum voluntary contraction, and force levels during dorsi- and plantarfiexion were recorded. Standard deviation and sample entropy of force signals were calculated and root mean square and sample entropy were calculated from sEMG signals. Differences among groups of force and sEMG variables were verified using a multivariate analysis of variance. Findings: Overall, during dorsiflexion contractions, moderate and severe subjects had higher force standard deviation and moderate subjects had lower force sample entropy. During plantarflexion, moderate subjects had higher force standard deviation and all diabetic subjects had lower entropy. Tibialis anterior presented higher root mean square in absent group and lower entropy in mild subjects. For gastrocnemius medialis, entropy was higher in severe and lower in moderate subjects. Interpretation: Diabetic neuropathy affects the complexity of the neuromuscular system during low-level isometric contractions, reducing the system's capacity to adapt to challenging mechanical demands. The observed patterns of neuromuscular complexity were not associated with disease severity, with the majority of alterations recorded in moderate subject. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 13/05580-5 - Dynamic muscles recruitment patterns using high-density EMG of diabetic patients in different severity degrees classified by a fuzzy system
• Grantee: Isabel de Camargo Neves Sacco
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/06123-7 - Dynamic muscles recruitment patterns during gait using high-density EMG of diabetic patients in different severity degrees classified by a fuzzy system
• Grantee: Eneida Yuri Suda
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 15/00214-6 - Complexity of motor control in different motor tasks and populations
• Grantee: Eneida Yuri Suda
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate