title: Age-related differences in knee extension rate of isometric force development and vertical jumping performance in women.
abstract: OBJECTIVE
  The purpose of this study was to compare knee extension rate of isometric force development and vertical jumping performance characteristics in young, middle-aged and elderly women.
  
  
  METHODS
  Unilateral knee extension maximal rate of isometric force development (RFD) was measured by a dynamometer. Maximal squat (SJ) and counter-movement jumps (CMJ) were performed on a force platform. Twelve young (21- to 24-year-old), 12 middle-aged (50- to 58-year-old) and 13 elderly (70- to 76-year-old) women participated.
  
  
  RESULTS
  Young women had greater (p<0.05) maximal isometric RFD as compared to older groups. No significant differences in maximal isometric RFD between middle-aged and elderly women have been found. The jumping height in SJ and CMJ was greater in young women as compared to older groups, and in middle-aged women greater as compared to elderly women. Absolute and body mass-related values of CMJ height was greater as compared to SJ height only in young women. Young women had greater jumping height relative to body mass in SJ and CMJ than the other groups.
  
  
  CONCLUSIONS
  The ability to develop isometric force of the knee extensor muscles rapidly did not differ significantly in middle-aged and elderly women. Middle-aged and elderly women had a reduced ability to use the potentiating effect of stretch-shortening cycle to vertical jumping performance during CMJ.
authors.affiliation: Institute of Exercise Biology and Physiotherapy, University of Tartu, Tartu, Estonia. matip@ut.ee
authors.forename: M
authors.initials: M
authors.lastname: Pääsuke
authors.forename: J
authors.initials: J
authors.lastname: Ereline
authors.forename: H
authors.initials: H
authors.lastname: Gapeyeva
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D005260:Female; D006801:Humans; D007717:Knee / Q000502:physiology*; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D013647:Task Performance and Analysis