title: The double crush syndrome: a common occurrence in cyclists with ulnar nerve neuropathy-a case-control study.
abstract: OBJECTIVE
  To evaluate the incidence of double crush syndrome in the upper limbs of cyclists with clinical diagnosis of ulnar nerve neuropathy.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Outpatient clinics and university setting.
  
  
  METHODS
  Consecutive sampling of 70 cyclists (140 upper limbs) with a mean age of 36 years (+/-11.3). Seventy-two upper limbs were excluded, leaving 40 upper limbs with a clinical diagnosis of ulnar nerve neuropathy [ULNN (+)] and 28 without symptoms of ulnar nerve neuropathy [ULNN (-)].
  
  
  RESULTS
  Cyclists were examined clinically for the presence of proximal dysfunction using the following testing (independent variables): (1) thoracic outlet syndrome provocation testing: elevated arm stress test and modified Cyriax release test; (2) presence of an elevated first rib: cervical rotation lateral flexion test; and (3) presence of proximal symptoms: reports of neck pain and shoulder pain.
  
  
  METHODS
  The upper limbs of cyclists were categorized into 2 groups (dependent variable)-ULNN (+) and ULNN (-)-based on history, symptoms, motor, sensory, and provocative clinical testing.
  
  
  RESULTS
  A significantly greater number of upper limbs of cyclists with ULNN (+) presented with positive provocative testing for thoracic outlet syndrome (elevated arm stress test P = 0.005; modified Cyriax release test P = 0.002) than did the upper limbs of cyclists with ULNN (-). The likelihood for the presence of neck pain, shoulder pain, and an elevated first rib was 3, 5, and 12 times greater, respectively, in the ULNN (+) than the ULNN (-) group.
  
  
  CONCLUSIONS
  A statistically significant greater number of the upper limbs of cyclists with clinical diagnosis of ulnar nerve neuropathy presented with proximal dysfunctions suggestive of double crush syndrome.
authors.affiliation: Center of Rehabilitation Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA.
authors.forename: Tanya M
authors.initials: TM
authors.lastname: Smith
authors.forename: Steven F
authors.initials: SF
authors.lastname: Sawyer
authors.forename: Phillip S
authors.initials: PS
authors.lastname: Sizer
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Brismée
mesh_terms: D000293:Adolescent; D000328:Adult; D001642:Bicycling / Q000293:injuries*; D016022:Case-Control Studies; D003444:Crush Syndrome / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015205:Northwestern United States / Q000453:epidemiology; D015206:Southwestern United States / Q000453:epidemiology; D017769:Ulnar Nerve Compression Syndromes / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology