title: Torque steadiness and muscle activation are bilaterally impaired during shoulder abduction and flexion in chronic post-stroke subjects.
abstract: OBJECTIVE
  To characterize sensorimotor control and muscle activation in the shoulder of chronic hemiparetic during abduction and flexion in maximal and submaximal isometric contractions. Furthermore, to correlate submaximal sensorimotor control with motor impairment and degree of shoulder subluxation.
  
  
  METHODS
  Thirteen chronic hemiparetic post-stroke age-gender matched with healthy were included. Isometric torques were assessed using a dynamometer. Electromyographic activity of the anterior and middle deltoid, upper trapezius, pectoralis major and serratus anterior muscles were collected. Variables were calculated for torque: peak, time to target, standard deviation (SD), coefficient of variation (CV), and standard error (RMSE); for muscle activity: maximum and minimum values, range and coefficient of activation. Motor impairment was determined by Fugl-Meyer and shoulder subluxation was measured with a caliper.
  
  
  RESULTS
  Paretic and non-paretic limbs reduced peak and muscle activation during maximal isometric contraction. Paretic limb generated lower force when compared with non-paretic and control. Paretic and non-paretic presented higher values of SD, CV, RMSE, and CV for prime mover muscles and minimum values for all muscles during steadiness. No correlation was found between sensorimotor control, motor impairment and shoulder subluxation.
  
  
  CONCLUSIONS
  Chronic hemiparetic presented bilateral deficits in sensorimotor and muscle control during maximal and submaximal shoulder abduction and flexion.
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil. Electronic address: gabrielalsantos@hotmail.com.
authors.forename: Gabriela Lopes
authors.initials: GL
authors.lastname: Santos
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil; Physical Therapy Program, School of Medicine and Health Science, University of Rosario, Bogotá, D.C., Colombia.
authors.forename: Luisa Fernanda
authors.initials: LF
authors.lastname: García-Salazar
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil.
authors.forename: Matheus Bragança
authors.initials: MB
authors.lastname: Souza
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil.
authors.forename: Ana Beatriz
authors.initials: AB
authors.lastname: Oliveira
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil.
authors.forename: Paula Rezende
authors.initials: PR
authors.lastname: Camargo
authors.affiliation: Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil.
authors.forename: Thiago Luiz
authors.initials: TL
authors.lastname: Russo
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D004576:Electromyography / Q000379:methods; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology / Q000503:physiopathology*; D010291:Paresis / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D016059:Range of Motion, Articular / Q000502:physiology; D012782:Shoulder / Q000502:physiology / Q000503:physiopathology*; D020521:Stroke / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D064171:Superficial Back Muscles / Q000503:physiopathology; D019415:Torque
keywords: Paresis; Proprioceptive feedback; Sensorimotor feedback; Upper extremity