title: Age-associated changes in hand grip and quadriceps muscle strength ratios in healthy adults.
abstract: OBJECTIVE
  Muscle strength may decline with age differentially in the upper and lower limbs. This information is difficult to capture through a single measure. The present study therefore aimed to characterize the relative changes in handgrip and lower limb muscle strength with aging by expressing them as a ratio.
  
  
  METHODS
  Thirty-eight healthy volunteers aged 20-82 years performed maximal voluntary contractions (MVC) of quadriceps and handgrip using a custom-built transducer and a Jamar dynamometer respectively.
  
  
  RESULTS
  The grip-quadriceps ratios for young adults was similar in males and females (0.75); indicating knee extensor force exceeded grip force by approximately 25%. Ratios were increased in older adults (p=0.05), and strength of the two muscle groups was approximately equal (1.1). Pearson's correlation coefficients for grip against quadriceps strength were r=0.63 (young males), r=0.83 (young females), r=0.35 (older males) and r=0.05 (older females).
  
  
  CONCLUSIONS
  The ratio used demonstrated clear differences between the age groups. The reduced muscle strength with increasing age was expected, but the higher grip/quadriceps strength ratios quantify a greater loss of quadriceps than grip strength with aging. It remains to be investigated whether the relatively greater rate of decline in quadriceps strength seen in healthy older people is more exaggerated in those who are frail, which would have implications for using grip strength as a physical marker of lower limb strength and function in those at risk of immobility and falls.
authors.affiliation: Faculty of Health Sciences, University of Southampton, Highfield, UK. D.Samuel@soton.ac.uk
authors.forename: Dinesh
authors.initials: D
authors.lastname: Samuel
authors.forename: Keely
authors.initials: K
authors.lastname: Wilson
authors.forename: Helen J
authors.initials: HJ
authors.lastname: Martin
authors.forename: Robert
authors.initials: R
authors.lastname: Allen
authors.forename: Avan Aihie
authors.initials: AA
authors.lastname: Sayer
authors.forename: Maria
authors.initials: M
authors.lastname: Stokes
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D005121:Extremities / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology*; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D010865:Pilot Projects; D052097:Quadriceps Muscle / Q000502:physiology*; D055815:Young Adult