title: Exercise- and Stress-Induced Hypoalgesia in Musicians with and without Shoulder Pain: A Randomized Controlled Crossover Study.
abstract: BACKGROUND
  Professional and pre-professional musicians are characterized by physical and psychological demands inherent to their musical activity, and therefore at risk for developing performance related musculoskeletal pain. Physical and psychological demands are known to influence human pain modulation.
  
  
  OBJECTIVE
  In this study we compared the influence of a physically and emotionally stressful task on pain thresholds in musicians with and without shoulder pain.
  
  
  METHODS
  A single-blinded randomized and controlled crossover study design was used to compare the effects of a physical versus emotional testing procedure on pressure pain thresholds (PPTs) in musicians with and without shoulder pain.
  
  
  METHODS
  All data were obtained in the field (e.g., at the physiotherapy accommodation in the Royal Conservatory).
  
  
  METHODS
  During the physical testing procedure, the subjects performed an isometric exercise of the glenohumeral external rotators. The emotional task comprised watching "unpleasant" images selected from the International Affective Picture System. The outcome was the assessment of change in PPTs before and after the physical and emotional task.
  
  
  RESULTS
  Our results indicate similar effects of both protocols in either group, i.e., musicians with and without shoulder pain (P > 0.05). All musicians showed elevated PPTs at local and remote areas after isometric exercise (P < 0.05). The emotional stress task increased PPTs at remote areas only (P < 0.05).
  
  
  CONCLUSIONS
  Despite the small sample size of musicians without shoulder pain, a power of 78.5% was achieved to detect the necessary effect size of Cohen's d = 1. Furthermore, comparing these results with those of non-musicians (both healthy subjects and patients with shoulder pain) might reveal information regarding the specific adaptations. Finally a high variability was observed in shoulder disability (i.e., SDQ-scores) as typically seen in a population with shoulder pain.
  
  
  CONCLUSIONS
  In musicians with and without regional shoulder pain, no significant differences were found with respect to pain modulation during a physically and an emotionally stressful task. Both interventions adequately activated central and widespread pain inhibitory mechanisms in both groups.
authors.forename: Kevin
authors.initials: K
authors.lastname: Kuppens
authors.affiliation: Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine and Health Sciences, University of Antwerp, Belgium; Pain in Motion Research Group, www.paininmotion.be.
authors.forename: Filip
authors.initials: F
authors.lastname: Struyf
authors.affiliation: Pain in Motion Research Group (www.paininmotion.be); Department of Human Physiology and Physiotherapy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium; Department of Physical Medicine and Physiotherapy, University Hospital Brussels, Brussels, Belgium.
authors.forename: Jo
authors.initials: J
authors.lastname: Nijs
authors.forename: Patrick
authors.initials: P
authors.lastname: Cras
authors.affiliation: 6StatUa Center for Statistics, University of Antwerp, Antwerp, Belgium.
authors.forename: Erik
authors.initials: E
authors.lastname: Fransen
authors.forename: Linda
authors.initials: L
authors.lastname: Hermans
authors.affiliation: Pain in Motion Research Group (www.paininmotion.be); Rehabilitation Sciences and Physiotherapy, Faculty of Medicine & Health Sciences, Ghent University, Ghent, Belgium; Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine & Health Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Mira
authors.initials: M
authors.lastname: Meeus
authors.forename: Nathalie
authors.initials: N
authors.lastname: Roussel
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009146:Music / Q000523:psychology*; D009784:Occupational Diseases / Q000175:diagnosis / Q000209:etiology / Q000523:psychology*; D010147:Pain Measurement / Q000379:methods / Q000523:psychology; D017288:Pain Threshold / Q000502:physiology / Q000523:psychology*; D020069:Shoulder Pain / Q000175:diagnosis / Q000209:etiology / Q000523:psychology*; D016037:Single-Blind Method; D013315:Stress, Psychological / Q000175:diagnosis / Q000209:etiology / Q000523:psychology*