Determination of the contractile characteristics of the motor units in skeletal muscle through twitch characteristics

  • J. S. Petrofsky
  • C. A. Phillips
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Abstract

A stepwise increase in stimulation voltage was applied to a pair of synchronously firing plate electrodes placed across the spinal roots innervating the soleus, medial and lateral gastrocnemius muscles of the cat. The resultant muscle twitches were stored and analysed by an Intel 8080a microprocessor to determine the speed of contraction and the peak tension of the compound muscle twitches. From these results, the speed of contraction and the strength distribution of the motor units within that muscle were estimated. These data were then compared with the actual fibre composition and speed distribution measured for the same three muscles. The results of these determinations showed that the distribution of strength and speed of contraction of the motor units of these muscles could be approximated through stimulation of their motor nerves.

Keywords

Contractile characteristics Motor units Muscle Twitch characteristics 
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Copyright information

© IFMBE 1979

Authors and Affiliations

  • J. S. Petrofsky
    • 1
    • 2
  • C. A. Phillips
    • 1
    • 2
  1. 1.Department of PhysiologySt. Louis UniversitySt. LouisUSA
  2. 2.Departments of Physiology and EngineeringWright State UniversityDaytonUSA

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