The orderly recruitment of motor units of the masseter and temporal muscles during voluntary isometric contraction in man

J Physiol. 1977 Feb;265(1):163-74. doi: 10.1113/jphysiol.1977.sp011710.


1. The contractile properties of the motor units of the masseter and temporal muscles of human subjects were studied during voluntary isometric contractions, using a method previously employed to examine units of a small hand muscle. 2. Over the range of forces studied (0-6 kg), the units of both muscles were recruited in an orderly fashion, with a nearly linear relationship between the voluntary force at which units were recruited and their measured twitch tensions. 3. The range of contraction times (25-90 msec) was similar to that observed for the hand muscle. In some subjects it seemed that small units, recruited at low forces, exhibited shorter contraction times.

MeSH terms

  • Action Potentials
  • Hand / physiology
  • Humans
  • Masticatory Muscles / physiology*
  • Motor Neurons / physiology*
  • Muscle Contraction*
  • Muscles / physiology
  • Neural Conduction