title: Effects of chronic neck-shoulder pain on normalized mutual information analysis of surface electromyography during functional tasks.
abstract: To investigate the effects neck-shoulder pain on the connectivity of surface electromyography (SEMG) signals during functional tasks.
  
  
  
  Twenty adults suffering from chronic neck-shoulder pain and 20 healthy controls were recruited. The SEMG signals from the left and right proximal cervical erector spinae, upper trapezius, lower trapezius and distal extensor carpi radialis, extensor digitorum, flexor digitorum superficialis and, abductor pollicis brevis were recorded during three functional tasks: unilateral and bilateral texting on a smart-phone and computer typing. Normalized mutual information (NMI) values were computed between homonymous proximal and distal muscle pairs as an index of the functional connectivity between muscles pairs.
  
  
  
  NMI among homonymous muscles pairs as well as among proximal and distal muscles pairs were lower among cases compared with controls. Moreover, NMI values in homonymous proximal muscles were higher during texting compared with computer typing with both hands.
  
  
  
  Our results show for the first time that chronic neck-shoulder pain affects the functional connectivity of muscle pairs.
  
  
  
  The study furnishes novel information about the effects of chronic neck-shoulder pain on the interplay of muscle pairs during functional tasks.
authors.affiliation: Physical Activity and Human Performance Research Group, SMI, Department of Health Science and Technology, Aalborg University, Fredrik Bajersvej 7, 9220 Aalborg East, Denmark. Electronic address: pm@hst.aau.dk.
authors.forename: Pascal
authors.initials: P
authors.lastname: Madeleine
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region. Electronic address: yanfei.xie@connect.polyu.hk.
authors.forename: Yanfei
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region. Electronic address: grace.szeto@polyu.edu.hk.
authors.forename: Grace P Y
authors.initials: GPY
authors.lastname: Szeto
authors.affiliation: Physical Activity and Human Performance Research Group, SMI, Department of Health Science and Technology, Aalborg University, Fredrik Bajersvej 7, 9220 Aalborg East, Denmark. Electronic address: afsamani@hst.aau.dk.
authors.forename: Afshin
authors.initials: A
authors.lastname: Samani
mesh_terms: D000328:Adult; D059350:Chronic Pain / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D004576:Electromyography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D019547:Neck Pain / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D010147:Pain Measurement / Q000379:methods* / Q000523:psychology; D011597:Psychomotor Performance / Q000502:physiology; D020069:Shoulder Pain / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D055815:Young Adult
keywords: Coordination; Muscle connectivity; Muscle interplay; Spatio-temporal organization