title: Axonal velocities of motor units in the hand and foot muscles of the baboon.
abstract: The axonal velocities of single motor units in the small hand and foot muscles of the baboon were studied by means of a collision technique which produced selective blocking of most of the fast-conducting fibres. In the abductor pollicis brevis muscle velocities ranged from 43 to 82 m/sec, and in the abductor digiti minimi muscle from 40 to 78 m/sec. In the extensor digitorum brevis muscle the range was 40-70 m/sec. When velocities were plotted as percentages of the maximal obtained in the same experiment, the range was similar in the 3 muscles studied. Most motor units had velocities greater than 65% of maximal but, in a few, velocities were between 55% and 65% of maximal. The possible relevance of these findings to human motor nerves is discussed.
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology*; D005071:Evoked Potentials; D005260:Female; D005528:Foot / Q000294:innervation*; D006225:Hand / Q000294:innervation*; D000882:Haplorhini; D009046:Motor Neurons / Q000502:physiology; D009132:Muscles / Q000294:innervation*; D009431:Neural Conduction; D010215:Papio / Q000502:physiology*; D011930:Reaction Time