title: Accuracy of electromyography needle placement in cadavers: non-guided vs. ultrasound guided.
abstract: BACKGROUND
  Accuracy of needle electromyography is typically ensured by use of anatomical landmarks and auditory feedback related to voluntary activation of the targeted muscle; however, in certain clinical situations, landmarks may not be palpable, auditory feedback may be limited or not present, and targeting a specific muscle may be more critical. In such settings, image guidance might significantly enhance accuracy.
  
  
  METHODS
  Two electromyographers with different levels of experience examined 14 muscles in each of 4 fresh-frozen cadaver lower limbs. Each muscle was tested a total of eight times; four fine wires were inserted without ultrasound (US) guidance and four were inserted under US guidance. Overall accuracy as well as accuracy rates for the individual electromyographers were calculated.
  
  
  RESULTS
  Non-guided needle placement was significantly less accurate than US-guided needle placement, particularly in the hands of less experienced electromyographers, supporting the use of real-time US guidance in certain challenging situations in the electromyography laboratory.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, Minnesota 55905, USA. boon.andrea@mayo.edu
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: Boon
authors.forename: Theresa M
authors.initials: TM
authors.lastname: Oney-Marlow
authors.forename: Naveen S
authors.initials: NS
authors.lastname: Murthy
authors.forename: Charles M
authors.initials: CM
authors.lastname: Harper
authors.forename: Terrence R
authors.initials: TR
authors.lastname: McNamara
authors.forename: Jay
authors.initials: J
authors.lastname: Smith
mesh_terms: D002102:Cadaver; D004576:Electromyography / Q000295:instrumentation* / Q000592:standards*; D006801:Humans; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D009339:Needles / Q000592:standards*; D015203:Reproducibility of Results; D014463:Ultrasonography / Q000379:methods / Q000592:standards