Comparison of EMG activity between maximal manual muscle testing and cybex maximal isometric testing of the quadriceps femoris

Hui Ting Lin, Ar Tyan Hsu, Jia Hao Chang, Chi Sheng Chien, Guan Liang Chang

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13 Citations (Scopus)


Two methods have been used to produce a maximal voluntary isometric contraction (MVIC) of the superficial quadriceps femoris muscles for normalization of electromyographic (EMG) data. The purposes of this study were to compare the myoelectic activity of MVIC of manual muscle testing (MMT) versus Cybex maximal isometric testing. Eighteen normal subjects were recruited. MMT and Cybex testing for MVIC of the dominant leg were performed. EMG activities of the vastus medialis, vastus lateralis and rectus femoris were recorded during MMT and Cybex trials. EMG amplitude and median frequency obtained from the two methods (MMT and Cybex testing) were used for statistical analysis of these three muscles. Statistically, the difference in the mean of the EMG signal amplitude and median frequency between MMT and Cybex testing were not significant. Considering cost and time, MMT for MVIC technique appears to be reliable and highly valuable.

Original languageEnglish
Pages (from-to)175-180
Number of pages6
JournalJournal of the Formosan Medical Association
Issue number2
Publication statusPublished - 2008 Feb



  • Cybex maximal isometric testing
  • Electromyography
  • Manual muscle testing
  • Quadriceps femoris

ASJC Scopus subject areas

  • Medicine(all)

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