The modified sphygmomanometer test for assessment of muscle strength of community-dwelling older adults in clinical practice: reliability and validity

Abstract

Purpose (a) to investigate the test-retest and inter-rater reliabilities and the criterion-related validity of the modified sphygmomanometer test (MST) for the assessment of muscle strength in community-dwelling older adults, (b) to calculate the standard error of measurement (SEM) and the smallest real difference (SRD); (c) to verify whether the number of trials affect the results. Methods Bilateral strength of lower limbs (LL) and grip muscles were evaluated with the MST and with portable dynamometers in 50 older adults (69.92 ± 5.52 years). Intra-class Correlation Coefficients (ICC) was used to evaluate the inter-rater and test-retest reliabilities and Pearson Correlations was used to investigate the criterion-related validity of the MST. SEM and SRD were also calculated. Analysis of variance was used to investigate whether the number of trials affects the results. Results Significant correlations with high to very high magnitude were found for all muscle groups evaluated for test-retest and inter-rater reliabilities (0.80 ≤ ICC ≤ 0.99; p < 0.001) and validity (0.80 ≤ r ≤ 0.91; p < 0.001). Moreover, the values provided by different numbers of trials were similar. The SEM (3.66 ≤ SEM ≤ 20.46) and the SRD (10.15 ≤ SRD95% ≤ 56.70) were considered low for all outcome measures. Conclusion The MST showed adequate results for all the measurement properties evaluated for the assessment of the muscle strength of older adults. Implications for rehabilitation Older adults often develop sarcopenia and dynapenia that are associated with an increased number of falls and fractures and loss of independence. Portable dynamometer is the standard instrument to evaluate isometric muscle strength, however this instrument is expensive and it is not readily available in the underdeveloped or in developed countries. The Modified Sphygmomanometer Test is an alternative method for the clinical measurement of muscle strength, is portable, has a low-cost and provides an objective measurement. In this study the Modified Sphygmomanometer Test showed adequate results for all the measurement properties evaluated for the assessment of the muscle strength in community-dwelling older adults and a single trial after test familiarization can be used to measure the muscle strength in this population.