Effects of different extents of pulley release on tendon excursion efficiency and tendon moment arms

Szu-Ching Lu, Tai-Hua Yang, Li-Chieh Kuo, I-Ming Jou, Yung-Nien Sun, Fong-Chin Su

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5 Citations (Scopus)


To compare the excursion efficiency and moment arms of flexor digitorum superficialis (FDS) and profundus (FDP) among different conditions of pulley integrity related to trigger finger treatment, cadaveric fingers were first tested with an intact pulley system, and then the first (A1) and second (A2) annular pulleys were released gradually from the proximal to distal part. Linear position sensors and a motion capture system were used to measure the tendon excursion and joint rotation simultaneously. The tendon excursion efficiency was defined as the range of motion of the involved joints per unit of tendon excursion, and the tendon moment arm was determined by the slope of the linear fitting result of tendon excursion versus metacarpophalangeal (MCP) joint rotation. No significant differences were found between the release of the A1 pulley and the release extending to half the proximal part of the A2 pulley in the FDP excursion efficiency and the moment arms of FDS and FDP with respect to the MCP joint. These results imply that the release could extend to half the proximal A2 pulley, if necessary, without significantly decreasing the FDP excursion efficiency and increasing the moment arms of FDS and FDP with respect to the MCP joint.

Original languageEnglish
Pages (from-to)224-228
Number of pages5
JournalJournal of Orthopaedic Research
Issue number2
Early online date8 Oct 2014
Publication statusPublished - 28 Feb 2015


  • aged
  • female
  • hand joints
  • humans
  • male
  • middle aged
  • tendons
  • trigger finger disorder

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