Reliability and validity of the modified sphygmomanometer test for the assessment of strength of upper limb muscles after stroke.

Abstract

To investigate the reliability (test-retest and inter-rater) and criterion-related validity of the modified sphygmomanometer test (MST) for the assessment of upper limb muscle strength in subjects with chronic stroke, and to determine whether the results are affected by the number of trials. The strength of 11 upper limb muscle groups of 57 subjects with stroke was bilaterally assessed with portable dynamometers and the MST (measured in mmHg). To investigate whether the number of trials would affect the results, 1-way analysis of variance was applied. For the test-retest/inter-rater reliabilities and criterion-related validity of the MST, intra-class correlation coefficients (ICCs), Pearson's correlation coefficients, and coefficients of determination were calculated. Different numbers of trials provided similar values for all assessed muscles (0.01 ≤ F ≤ 0.18; 0.83 ≤ p ≤ 0.99) with adequate test-retest (0.83 ≤ ICC ≤ 0.97; p < 0.0001) and inter-rater reliabilities (0.79 ≤ ICC ≤ 0.97; p < 0.0001) and validity (0.61 ≤ r ≤ 0.95; p < 0.0001). The values obtained with the MST were good predictors of those obtained with portable dynamometers (0.60 ≤ r2 ≤ 0.86), except for pinch strength (0.39 ≤ r2 ≤ 0.54). The MST showed adequate measurement properties for the assessment of the strength of the upper limb muscles of subjects with chronic stroke. After familiarization a single trial provided adequate strength values.