Validity and reliability of the Modified Sphygmomanometer Test with fixed stabilization for clinical measurement of muscle strength.

OBJECTIVE: To investigate the concurrent validity of the Modified Sphygmomanometer Test (MST) with fixed stabilization, compared to the portable dynamometer, and to verify its test-retest and inter-raterreliability. METHODS: Methodological study. The muscle strength of the following groups was measured: flexors and extensors of the wrist, of the hip, and of the knee and plantar flexors. The Tycos® aneroid sphygmomanometer and the Microfet 2® dynamometer were used. Stabilization was performed using the Mullingan® belt. Descriptive statistics were performed for characterization of the sample. To determine the validity of the MST with fixed stabilization, comparing it with the portable dynamometer, we investigated the correlation between the measurements obtained with the two instruments using the Pearson correlation coefficient. Intraclass Correlation Coefficient (ICC) was used to investigate inter-examiner and test-retest reliability (α = 0.05). RESULTS: 59 individuals were included (1176 evaluations). A statistically significant correlation of moderate to high magnitude (0.58 ≤ r ≤ 0.81) was observed for concurrent validity of the MST with fixed stabilization versus the portable dynamometer for all muscle groups. Regarding inter-rater reliability, it was observed statistically significant ICC considered excellent to good (0.72 ≤ r ≤ 0.94) for all muscle groups. Regarding test-retest reliability, first evaluator presented good to excellent ICC (0.64 ≤ r ≤ 0.94), while second evaluator presented good to excellent ICC (0.74 ≤ r ≤ 0.96) for all muscle groups. CONCLUSION: The MST with fixed stabilization is valid and reliable for clinical measurement of muscle strength and can overcome previous limitations reported in the literature.