title: Reliability and relationships among handgrip strength, leg extensor strength and power, and balance in older men.
abstract: OBJECTIVE
  To quantify the reliability of isometric leg extension torque (LEMVC), rate of torque development (LERTD), isometric handgrip force (HGMVC) and RFD (HGRFD), isokinetic leg extension torque and power at 1.05rad·s(-1) and 3.14rad·s(-1); and explore relationships among strength, power, and balance in older men.
  
  
  METHODS
  Sixteen older men completed 3 isometric handgrips, 3 isometric leg extensions, and 3 isokinetic leg extensions at 1.05rad·s(-1) and 3.14rad·s(-1) during two visits. Intraclass correlation coefficients (ICCs), ICC confidence intervals (95% CI), coefficients of variation (CVs), and Pearson correlation coefficients were calculated.
  
  
  RESULTS
  LERTD demonstrated no reliability. The CVs for LERTD and HGRFD were ≤23.26%. HGMVC wasn't related to leg extension torque or power, or balance (r=0.14-0.47; p>0.05). However, moderate to strong relationships were found among isokinetic leg extension torque at 1.05rad·s(-1) and 3.14rad·s(-1), leg extension mean power at 1.05rad·s(-1), and functional reach (r=0.51-0.95; p≤0.05).
  
  
  CONCLUSIONS
  LERTD and HGRFD weren't reliable and shouldn't be used as outcome variables in older men. Handgrip strength may not be an appropriate surrogate for lower body strength, power, or balance. Instead, perhaps handgrip strength should only be used to describe upper body strength or functionality, which may compliment isokinetic assessments of lower body strength, which were reliable and related to balance.
authors.affiliation: University of Nebraska-Lincoln, 211 Ruth Leverton Hall, Lincoln, NE 68583, United States.
authors.forename: Nathaniel D M
authors.initials: ND
authors.lastname: Jenkins
authors.affiliation: University of Nebraska-Lincoln, 211 Ruth Leverton Hall, Lincoln, NE 68583, United States.
authors.forename: Samuel L
authors.initials: SL
authors.lastname: Buckner
authors.affiliation: University of Nebraska-Lincoln, 211 Ruth Leverton Hall, Lincoln, NE 68583, United States.
authors.forename: Haley C
authors.initials: HC
authors.lastname: Bergstrom
authors.affiliation: University of Nebraska-Lincoln, 211 Ruth Leverton Hall, Lincoln, NE 68583, United States.
authors.forename: Kristen C
authors.initials: KC
authors.lastname: Cochrane
authors.affiliation: University of Nebraska-Lincoln, 211 Ruth Leverton Hall, Lincoln, NE 68583, United States.
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Goldsmith
authors.affiliation: University of Nebraska-Lincoln, 211 Ruth Leverton Hall, Lincoln, NE 68583, United States.
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Housh
authors.affiliation: University of Nebraska-Lincoln, 211 Ruth Leverton Hall, Lincoln, NE 68583, United States.
authors.forename: Glen O
authors.initials: GO
authors.lastname: Johnson
authors.affiliation: University of Nebraska-Lincoln, 211 Ruth Leverton Hall, Lincoln, NE 68583, United States.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schmidt
authors.affiliation: University of Nebraska-Lincoln, 211 Ruth Leverton Hall, Lincoln, NE 68583, United States. Electronic address: jcramer@unl.edu.
authors.forename: Joel T
authors.initials: JT
authors.lastname: Cramer
mesh_terms: D000367:Age Factors; D000368:Aged; D000375:Aging; D015577:Geriatric Assessment / Q000379:methods*; D018737:Hand Strength; D006801:Humans; D007537:Isometric Contraction; D035002:Lower Extremity; D008297:Male; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000502:physiology*; D004856:Postural Balance; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012737:Sex Factors; D019415:Torque; D034941:Upper Extremity
keywords: Aging; Functionality; Intraclass correlation coefficient; Power; Rate of force development