title: Number and size of motor units in thenar muscles.
abstract: The number and size of motor units (MUs) in the thenar muscles of 10 fresh adult cadavers (33-74 years old) were estimated by histological methods. The average number of MUs was 161 +/- 26 and the MU size was 93 +/- 11.5. Adductor pollicis showed a significantly greater MU size. The number of MUs in our histological study was in agreement with the number reported in previous studies using multiple point stimulation, the method currently used in the clinical investigation of neuromuscular disorders.
authors.affiliation: Department of Anatomy, Institute of Biology, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Humberto Santo
authors.initials: HS
authors.lastname: Neto
authors.forename: José Meciano
authors.initials: JM
authors.lastname: Filho
authors.forename: Renato
authors.initials: R
authors.lastname: Passini
authors.forename: Maria Julia
authors.initials: MJ
authors.lastname: Marques
mesh_terms: D000328:Adult; D000368:Aged; D001369:Axons / Q000648:ultrastructure; D002102:Cadaver; D005260:Female; D006225:Hand / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology / Q000648:ultrastructure*; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000294:innervation*; D014459:Ulnar Nerve