Single-Trial Estimation of Quasi-Static EMG-to-Joint-Mechanical-Impedance Relationship over a Range of Joint Torques

Details

• Personal Author:
  Clancy EA ; Dai C ; Martel F ; Martel S ; Rancourt D
• Description:
  Joint mechanical impedance is commonly measured by applying dynamic perturbations about a joint at a fixed operating point/background torque, and quantifying torque change vs. angle change. Impedance characterization in functional tasks, therefore, requires multiple experimental trials over a range of operating points-a cumbersome, invasive, time-consuming and impractical task. As an alternative, studies have related EMG to impedance, after which EMG can estimate impedance without applying joint perturbations. But, the cumbersome calibration trials are still required. We describe a method of single contraction perturbations in which the background torque slowly ramps over the operating range, with EMG simultaneously acquired. Using one such "quasi-static" contraction for model training and another for testing, we show this method to be a reasonable surrogate for traditional second-order, linear impedance modeling. A simple, short-duration calibration results. We compared our single-trial ramp method to multiple constant background torque trials at 10, 20, 30, and 40% maximum effort (extension and flexion), finding only limited differences in traditional vs. EMG-based ramp impedance estimates (12-22%, most prominent at the two lower contraction levels). Such constant force and slowly-variable force contractions are relevant to many practical applications, including ergonomics assessment, prosthetic control and clinical biomechanics. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Ergonomics Occupational Health Safety
• Keywords:
  Author Keywords: Electromyography Biomechanical Modeling Biomechanics Electromyography Joint Impedance Least Squares Estimation Muscle Contraction Physiologic Modeling
• ISSN:
  1050-6411
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Massachusetts ; OSHA Region 1 ; OSHA Region 6 ; Texas
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  18-25
• Volume:
  45
• NIOSHTIC Number:
  nn:20068634
• Citation:
  J Electromyogr Kinesiol 2019 Apr; 45:18-25
• Contact Point Address:
  Edward A. Clancy, Worcester Polytechnic Institute, Department of Electrical and Computer Engineering, 100 Institute Road, Worcester, MA, United States
• Email:
  ted@wpi.edu
• Federal Fiscal Year:
  2019
• Performing Organization:
  Worcester Polytechnic Institute
• Peer Reviewed:
  True
• Start Date:
  20030915
• Source Full Name:
  Journal of Electromyography and Kinesiology
• End Date:
  20060914
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:756dbed7c7b384b9459248c111c97979b25b529df86ef77153d077dd223c732f2881c835cf89c2ecf543e7b10441f8d112a116150475519ec24c7edbc0f4c27c
• Download URL:
  https://stacks.cdc.gov/view/cdc/207236/cdc_207236_DS1.pdf
• File Type:
  [PDF - 4.26 MB ]