Predictors of Muscle Strength Assessed with the Modified Sphygmomanometer Test

Objectives: To investigate the best predictor of muscle strength assessed with both Modified Sphygmomanometer Test (MST) methods (bag adaptation and non-adapted) and to provide normative values for these two MST methods for the strength assessment of the trunk, upper, and lower limb muscles. Design: Cross-sectional study. Methods: The strength of 42 muscle groups were assessed with the MST in the bag adaptation and non-adapted methods in 120 healthy individuals, 50 % males, divided into three age groups (20-39, 40-59, 60-79) with 40 subjects per group. Stepwise multiple regression analysis was performed to investigate which independent variables (sex, age, and limb dominance) is the best predictor of muscle strength (alpha = 5 %). Results: Sex was the best independent predictor for all muscle groups for both MST methods (8.8 % < R2<57.8 %, p < 0.0001), except for the ankle plantar flexors assed with the non-adapted sphygmomanometer, in which age was the best independent predictor (R2 = 25.6 %; p < 0.0001). The normative values of muscle strength were reported for both MST methods considering the subgroups (sex, age, and limb dominance). Ceiling effect was observed when the MST bag adaptation was used to assess some muscles (8.8 %). Conclusion: Sex was the best predictor of muscle strength, as commonly found for muscle strength assessment with the dynamometer. The normative values provided have high clinical utility and can be used to interpret results of muscle strength assessment using both MST methods. For the MST in the bag adaptation method, caution is advised for the assessment of some muscles.