Digit I, III – Palm, Wrist

Surface Recording Technique, Orthodromic Study
  • Giuliano Gentili
  • Mario Di Napoli

Original Settings

Sensitivity was 10 μV/division, sweep speed was 1 ms/division, duration of pulse was 100–200 μs, and the machine used was a one-channel electromyograph DISA 14A30. Low-frequency filter, high-frequency filter, and rate of pulse were not specified.


This study was performed in the supine position.


Following the orthodromic method [ 1], signals were recorded at two different points (Figs. 1 and 2): on the palm (R1) and at the wrist (R2). On the palm (R1), the subdermal electrodes (both active and reference electrodes) were inserted well outside the zone of compression in the carpal tunnel, 1.5–2 cm distally to the distal edge of the flexor retinaculum. To record from the palmar nerve of digit I (thumb), the electrode was placed 6 cm from the stimulating cathode (−) at the medial border of the thenar eminence. To record from digit III (middle finger), the electrode was placed 9 cm from the stimulating cathode (−) along a line pointing to the midline of...


  1. 1.
    Buchthal F, Rosenfalck A (1971) Sensory conduction from digit to palm and from palm to wrist in the carpal tunnel syndrome. J Neurol Neurosurg Psychiatry 34:243–252PubMedCentralPubMedCrossRefGoogle Scholar
  2. 2.
    Bland JDP (2000) A neurophysiological grading scale for carpal tunnel syndrome. Muscle Nerve 23:1280–1283PubMedCrossRefGoogle Scholar

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • Giuliano Gentili
    • 1
  • Mario Di Napoli
    • 1
  1. 1.Neurological ServiceS. Camillo de’ Lellis General HospitalRietiItaly

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