title: Prediction of isometric motor tasks and effort levels based on high-density EMG in patients with incomplete spinal cord injury.
abstract: The development of modern assistive and rehabilitation devices requires reliable and easy-to-use methods to extract neural information for control of devices. Group-specific pattern recognition identifiers are influenced by inter-subject variability. Based on high-density EMG (HD-EMG) maps, our research group has already shown that inter-subject muscle activation patterns exist in a population of healthy subjects. The aim of this paper is to analyze muscle activation patterns associated with four tasks (flexion/extension of the elbow, and supination/pronation of the forearm) at three different effort levels in a group of patients with incomplete Spinal Cord Injury (iSCI).
  
  
  
  Muscle activation patterns were evaluated by the automatic identification of these four isometric tasks along with the identification of levels of voluntary contractions. Two types of classifiers were considered in the identification: linear discriminant analysis and support vector machine.
  
  
  
  Results show that performance of classification increases when combining features extracted from intensity and spatial information of HD-EMG maps (accuracy = 97.5%). Moreover, when compared to a population with injuries at different levels, a lower variability between activation maps was obtained within a group of patients with similar injury suggesting stronger task-specific and effort-level-specific co-activation patterns, which enable better prediction results.
  
  
  
  Despite the challenge of identifying both the four tasks and the three effort levels in patients with iSCI, promising results were obtained which support the use of HD-EMG features for providing useful information regarding motion and force intention.
authors.affiliation: Department of Automatic Control (ESAII), Biomedical Engineering Research Centre (CREB), Technical University of Catalonia UPC, Barcelona, Spain. Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Spain. Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, Barcelona, Spain.
authors.forename: Mislav
authors.initials: M
authors.lastname: Jordanić
authors.forename: Mónica
authors.initials: M
authors.lastname: Rojas-Martínez
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Mañanas
authors.forename: Joan Francesc
authors.initials: JF
authors.lastname: Alonso
mesh_terms: D000328:Adult; D000465:Algorithms; D004576:Electromyography; D005260:Female; D005542:Forearm / Q000503:physiopathology; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D008875:Middle Aged; D009048:Motor Skills; D018482:Muscle, Skeletal / Q000503:physiopathology; D005082:Physical Exertion; D011237:Predictive Value of Tests; D011403:Pronation / Q000502:physiology; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D013484:Supination / Q000502:physiology; D060388:Support Vector Machine