Reliability of maximal voluntary muscle strength and power testing in older men.
BACKGROUND
Maximal voluntary muscle strength (MVMS) and leg power are important measures of physical function in older adults. We hypothesized that performing these measures twice within 7-10 days would demonstrate a >5% increase due to learning and familiarization of the testing procedures.


METHODS
Data were collected from three studies in older adult men (60-87 years) and were divided into two cohorts defined by study site and type of exercise equipment. MVMS was assessed in 116 participants using the one-repetition maximum method at two separate study visits for the chest press, latissimus pull-down, leg press, leg flexion, and leg extension exercises along with unilateral leg extension power.


RESULTS
Test-retest scores were not different and did not exceed 0.8 +/- 9.0% in Cohort 1 or 2.3 +/- 9.8% in Cohort 2, except for leg extension, which improved by 6.6 +/- 14.4% (p <.009) and 3.4 +/- 6.8% (p <.016), respectively. Repeat tests were closely correlated with initial tests (all p <.001). Pearson correlation coefficients ranged from 0.74 for leg extension power to 0.96 for leg press. Coefficients of variation were <10% (4.2%-9.0%) for all exercises except for leg extension power, which was 15.5%.


CONCLUSIONS
Our findings demonstrated that test-retest measures of MVMS and power in older adult men do not differ by more than 2.3% except for leg extension, and have relatively low coefficients of variation using data collected from three studies. Moreover, these findings were similar between two study sites using different equipment, which further supports the reliability of MVMS and power testing in older adult men.
Schroeder
E Todd
ET
University of Southern California, Departments of Medicine and Biokinesiology & Physical Therapy, 1540 East Alcazar St., CHP-155, Los Angeles, CA 90089, USA. eschroed@usc.edu
Wang
Ying
Y
Castaneda-Sceppa
Carmen
C
Cloutier
Gregory
G
Vallejo
Alberto F
AF
Kawakubo
Miwa
M
Jensky
Nicole E
NE
Coomber
Susan
S
Azen
Stanley P
SP
Sattler
Fred R
FR
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001823:Body Composition; D015577:Geriatric Assessment; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D015203:Reproducibility of Results; D019876:Sports Equipment