title: Age-gender differences in the reaction times of ankle muscles.
abstract: OBJECTIVE
  Reaction times of the hip abductor were reported to be longer in elderly women than in elderly men, and this was suggested to be related to mediolateral balance performance. The aim of the present study was to investigate the effects of age and gender on the reaction performance of ankle muscles, which have predominant roles in anterioposterior balance control.
  
  
  METHODS
  A total of 40 elderly subjects and 40 young subjects (even number of men and women) carried out a series of isometric plantarflexions and dorsiflexions, as forcefully and quickly as possible, in response to auditory stimulus. Surface electromyogram at the dorsiflexor and plantarflexor were recorded, together with foot plantar force. Premotor time, motor time and total reaction time derived from the experimental data were compared between age groups and genders by two-way anova.
  
  
  RESULTS
  Both dorsiflexor and plantarflexor showed similar reaction performance. Premotor time increased with age with no gender difference. Motor time increased with age in women and not in men, resulting in longer motor time in elderly women than in elderly men. Total reaction time was dominated by premotor time, so that it was longer in the elderly with no gender difference.
  
  
  CONCLUSIONS
  Although age-related elongation of motor time was greater in women, total reaction time was not different between the genders. This may be related to no gender difference in anterioposterior balance performance.
authors.affiliation: Department of Control and Instrumentation Engineering, Korea University, Chungnam, Korea.
authors.forename: Junghwa
authors.initials: J
authors.lastname: Hong
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Hong-Young
authors.initials: HY
authors.lastname: Chung
authors.forename: Hyo-Hee
authors.initials: HH
authors.lastname: Kim
authors.forename: Yuri
authors.initials: Y
authors.lastname: Kwon
authors.forename: Chul-Seung
authors.initials: CS
authors.lastname: Kim
authors.forename: Ye-Ji
authors.initials: YJ
authors.lastname: Ho
authors.forename: Gwang-Moon
authors.initials: GM
authors.lastname: Eom
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Jun
authors.forename: Byung Kyu
authors.initials: BK
authors.lastname: Park
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D000842:Ankle / Q000502:physiology*; D004576:Electromyography; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012737:Sex Factors; D055815:Young Adult
keywords: ankle muscles; gender difference; postural control; reaction time