European Journal of Applied Physiology

, Volume 91, Issue 1, pp 22–29 | Cite as

Reliability and validity of the Biodex system 3 pro isokinetic dynamometer velocity, torque and position measurements

  • Joshua M. DrouinEmail author
  • Tamara C. Valovich-mcLeod
  • Sandra J. Shultz
  • Bruce M. Gansneder
  • David H. Perrin
Original Article


This study quantitatively assessed the mechanical reliability and validity of position, torque and velocity measurements of the Biodex System 3 isokinetic dynamometer. Trial-to-trial and day-to-day reliability were assessed during three trials on two separate days. To assess instrument validity, measurement of each variable using the Biodex System 3 dynamometer was compared to a criterion measure of position, torque and velocity. Position was assessed at 5° increments across the available range of motion of the dynamometer. Torque measures were assessed isometrically by hanging six different calibrated weights from the lever arm. Velocity was assessed (30°/s to 500°/s) across a 70° arc of motion by manually accelerating the weighted lever arm. With the exception of a systematic decrease in velocity at speeds of 300°/s and higher, the Biodex System 3 performed with acceptable mechanical reliability and validity on all variables tested.


Muscle function Muscle testing Reliability Validity 


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Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  • Joshua M. Drouin
    • 1
    Email author
  • Tamara C. Valovich-mcLeod
    • 2
  • Sandra J. Shultz
    • 3
  • Bruce M. Gansneder
    • 4
  • David H. Perrin
    • 5
  1. 1.Department of Public HealthGeorgia Southern UniversityStatesboroUSA
  2. 2.Department of Sports Health CareArizona School of Health SciencesMesaUSA
  3. 3.Department of Exercise and Sports ScienceUniversity of North CarolinaGreensboroUSA
  4. 4.Department of Education, Leadership and FoundationsUniversity of VirginiaCharlottesvilleUSA
  5. 5.School of Health and Human PerformanceUniversity of North Carolina at GreensboroGreensboroUSA

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