title: The influence of handedness on the distribution of muscular weakness of the arm in facioscapulohumeral muscular dystrophy.
abstract: The strength of 10 muscle groups in both arms was measured using hand-held myometry to determine the influence of handedness on left-right differences of muscle strength in facioscapulohumeral muscular dystrophy (FSHD). Two groups of subjects were studied: 24 healthy volunteers (19 right-handed), and 53 patients (42 right-handed) with autosomal dominant FSHD. An opposite left-right difference of strength of shoulder and arm muscles was found: right-handed volunteers were stronger on the right side, right-handed patients were stronger on the left side. This opposite left-right difference was statistically significant for the supraspinatus muscle, the wrist extensors and the shoulder internal rotators. The number of left-handed subjects was too small for statistical analysis. The relation between handedness and increased muscle weakness in right-handed FSHD patients suggests that mechanical factors may play a distinct role in the progression of muscle weakness in FSHD.
authors.affiliation: Department of Neurology, University of Leiden, The Netherlands.
authors.forename: O F
authors.initials: OF
authors.lastname: Brouwer
authors.forename: G W
authors.initials: GW
authors.lastname: Padberg
authors.forename: R J
authors.initials: RJ
authors.lastname: van der Ploeg
authors.forename: C J
authors.initials: CJ
authors.lastname: Ruys
authors.forename: R
authors.initials: R
authors.lastname: Brand
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000503:physiopathology*; D009136:Muscular Dystrophies / Q000503:physiopathology*