title: Quadriceps strength and executive functions in older women.
abstract: OBJECTIVE
  The aim of this study is to answer the question whether the strength of the knee extensor musculus quadriceps (m. quadriceps), in particular, is related to specific executive functions and whether this relationship is independent of aerobic fitness. The clinical relevance of this question is that the m. quadriceps can still be trained in older people and executive functions are the most vulnerable to processes of aging.
  
  
  METHODS
  In 41 cognitively intact older women, cognitive functioning was assessed by neuropsychological tests; isometric and isotonic quadriceps strength by the Quadrisotester and the 30-sec chair-stand test, respectively; and aerobic fitness by the 6-min walk test.
  
  
  RESULTS
  A significant proportion of the total variance of the executive functions, attention/working memory and inhibition, were explained by isometric/isotonic knee extensor strength and aerobic fitness, respectively. Extensor muscle strength, aerobic fitness, or one or more interactions did not explain a significant proportion of the total variance of other cognitive functions.
  
  
  CONCLUSIONS
  These data suggest that in older women, quadriceps strength is associated with the executive function, attention/working memory, and that this effect is independent of aerobic fitness, which seems to be associated more strongly with inhibition, another executive function.
authors.affiliation: Department of Clinical Neuropsychology, VU University, Amsterdam, The Netherlands.
authors.forename: E J A
authors.initials: EJ
authors.lastname: Scherder
authors.forename: L H P
authors.initials: LH
authors.lastname: Eggermont
authors.forename: R H
authors.initials: RH
authors.lastname: Geuze
authors.forename: J
authors.initials: J
authors.lastname: Vis
authors.forename: G J
authors.initials: GJ
authors.lastname: Verkerke
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D015331:Cohort Studies; D056344:Executive Function / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D015577:Geriatric Assessment; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D009483:Neuropsychological Tests; D010809:Physical Fitness; D011336:Probability; D052097:Quadriceps Muscle / Q000502:physiology*; D012044:Regression Analysis