title: A vascular basis for repetitive strain injury.
abstract: OBJECTIVE
  The blanket term 'repetitive strain injury' (RSI) covers a wide variety of work-related clinical syndromes, most of which are localized lesions. However, some patients complain of diffuse forearm pain, a clinically distinct form of RSI, the aetiology of which is unknown.
  
  
  METHODS
  Using Doppler ultrasound, we measured the vascular responses to muscular work in the radial artery in 13 patients with bilateral diffuse forearm pain, seven with unilateral diffuse pain and 19 controls with localized arm pain.
  
  
  RESULTS
  We found that in diffuse forearm pain the radial artery is relatively constricted compared to the controls and fails to vasodilate with exercise, which suggests that diffuse forearm pain may be due to physiological claudication of the working forearm muscle.
  
  
  CONCLUSIONS
  A possible explanation is inhibition of local endothelial nitric oxide function, and this may be an unusual secondary, but self-perpetuating, pain condition which can follow other more specific, but chronic, arm pain syndromes in susceptible individuals.
authors.affiliation: Department of Rheumatology, University Hospital of Wales, Heath Park, Cardiff, UK.
authors.forename: M H
authors.initials: MH
authors.lastname: Pritchard
authors.forename: N
authors.initials: N
authors.lastname: Pugh
authors.forename: I
authors.initials: I
authors.lastname: Wright
authors.forename: M
authors.initials: M
authors.lastname: Brownlee
mesh_terms: D000293:Adolescent; D000328:Adult; D012090:Cumulative Trauma Disorders / Q000503:physiopathology*; D005260:Female; D005542:Forearm / Q000098:blood supply / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism; D010146:Pain / Q000209:etiology; D017534:Radial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D018084:Ultrasonography, Interventional
chemical_list: D009569:Nitric Oxide