Valores de referência do teste do esfigmomanômetro modificado para avaliação clínica da força muscular de membros superiores, membros inferiores e tronco

Abstract

Muscle strength evaluation is usually performed in clinical settings. Among the measurement methods of this outcome, the Modified Sphygmomanometer Test (MST) is considered a good alternative, since it provides objective values of muscle strength and has low cost. Although the MST has adequate measurement properties for various muscle groups and different populations, the information on reference values is sparse and incomplete. Considering that reference values are relevantwithin clinical context, since they make possible the interpretation of the results of the evaluation, and the establishment of appropriate treatment targets, the objective of this study was to determine the reference values of muscle strength for two MST methods for the assessment of 22 muscle groups of upper limbs, lower limbs and trunk in healthy individuals. The strength of 20 bilateral muscles (shoulder, elbow, wrist, hip, knee and ankle flexors/extensors; shoulder and hip abductors; gripstrength; pulp-to-pulp, palmar and lateral pinch strength; trunk lateral flexors/rotators) and two unilateral muscles (trunk flexors/extensors) in 120 individuals, 60 males and 60 females (20-79 years), was evaluated by the MST bag method and by the MST without adaptation method. The evaluation of each individual was performed in a single day by two trained examiners: one of them performed muscle strength measurements, while the other performed the reading and recording of the values. Descriptive statistics were used to characterize the sample and to present the reference values. Multiple regression analysis was used to determine the effect of each independent variable (gender, age, side) on the dependent variable (muscle strength of each of the 22 muscle groups assessed by each one of the two MST methods) and, to determine the most appropriate way to present the reference values. For each MST method, reference values for muscle strength were determined for each subgroup: gender (male/female), age group (20-29, 30-39, 4049, 50-59, 60-69 and 70- 79) and side (dominant/non-dominant and right/left), as has been traditionally presented in studies with similar objectives. The measurement capability of the equipment when used on the MST bag method exceeded in almost a quarter of the subgroups (24.8%), and more than a half (56%) occurred in males aged 59 years. In 15.7% of the subgroups, these losses occurred in the minority of the individuals (four). However, in 9.1% of the subgroups these losses occurred in five or more individuals and it is believed that this amount of losses couldcompromise the reference values that were provided. On the other hand, the MST without adaptation method did not have the measurement capability exceeded, except for hip and knee extensors on the dominant side in the 40-49 age group, where there was only one loss in each. The reference values of muscle strength of the majority of the muscle groups (68.4%) for both genders and sides and in the different age groups presented a coefficient of variation (CV) between 10.1% and 20% for both MST methods. In only 1.8% the CV was higher than 30%. For individuals up to 59 years of age, the gender variable was the only predictor of muscle strength for 50% of the muscle groups evaluated with the MST bag method, and for 63.3% of the muscles groups evaluated with the MST without adaptation method. In the elderly, the gender variable was the only predictor for the majority of the muscle groups for both the MST bag method (81.8%) and the MST without adaptation method (72.7%). As there was no similarity between the predictors of muscle strength, it was not possible to determine an alternative way to present the reference values other than the traditionally used method: reference values for eachgender, age group and side. Therefore, reference values of muscle strength were determined for 22 muscle groups for the two MST methods and can be used to interpret the results of the evaluations. For the MST without adaptation method, reference values were adequately established for all muscle groups considering the different subgroups. For the MST bag method, some reference values, specifically 9.3%, were obtained considering the data of five or less individuals and therefore,these values should be used with caution.