title: Effect of age and sex on jumping mechanography and other measures of muscle mass and function.
abstract: OBJECTIVE
  Sarcopenia increases falls and fracture risk. Sarcopenia clinical trials require robust quantitative tools to evaluate muscle function; jumping mechanography (JM) is likely one such tool. However, US data comparing JM with traditional tests across the lifespan is limited. This study evaluated the effect of age and sex on JM compared with traditional function tests and lean mass.
  
  
  METHODS
  US adults (213 women/119 men; mean age 65.4 years, range 27-96) performed functional tests including JM, Short Physical Performance Battery (SPPB) and grip strength (GS). Appendicular lean mass (ALM) was measured using DXA.
  
  
  RESULTS
  Men had higher relative jump power [mean (SD) 28.5 (10.52) vs. 21.9 (7.11) W/kg], GS [35.5 (9.84) vs. 22.7 (6.98) kg] and ALM/ht(2) [8.25 (1.35) vs. 6.99 (1.38) kg/m2] (all p<0.0001); no difference was observed for SPPB components. JM parameters were more strongly correlated with age than traditional tests (R2=0.38-0.61 vs. R2=0.01-0.28) and weakly with GS and chair rise time (R2=0.30-0.36).
  
  
  CONCLUSIONS
  JM parameters are correlated with GS and chair rise time and demonstrate stronger correlations with age. JM shows promise as a valuable tool to evaluate and monitor interventions for sarcopenia as it could potentially detect change in muscle function more precisely than existing tools.
authors.affiliation: Osteoporosis Clinical Research Program, University of Wisconsin, Madison, WI.
authors.forename: E
authors.initials: E
authors.lastname: Siglinsky
authors.forename: D
authors.initials: D
authors.lastname: Krueger
authors.forename: R E
authors.initials: RE
authors.lastname: Ward
authors.forename: P
authors.initials: P
authors.lastname: Caserotti
authors.forename: E S
authors.initials: ES
authors.lastname: Strotmeyer
authors.forename: T B
authors.initials: TB
authors.lastname: Harris
authors.forename: N
authors.initials: N
authors.lastname: Binkley
authors.forename: B
authors.initials: B
authors.lastname: Buehring
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D018737:Hand Strength; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D055948:Sarcopenia / Q000175:diagnosis*; D012737:Sex Factors