Análise eletromiográfica e propriedades clinimétricas do teste muscular manual da cinesiologia aplicada

Abstract

Background: The Applied Kinesiology’s manual muscle test (AK-MMT) is a clinical assessment tool that can be used to identify motor control changes in neurologically healthy subjects. The AK-MMT classifies muscles as ‘facilitated’ or ‘inhibited’ and the hypothesis that explains this difference is that inhibited muscles present a latency delay. Objective: Investigate the hypothesis of the latency delay in inhibited muscles and test the clinimetric properties of the AK-MMT. Methods: A cross-sectional and methodological study was conducted in 38 participants with a mean age of 41.1 years (SD 14.8). Electromyography integrated with an electrical goniometer and a hand-held dynamometer were used to measure latency, angular displacement and muscle force of the gluteus medius muscles, respectively. Inter- and intra rater reliability of two examiners with different levels of experience were obtained using Intraclass Correlation Coefficient (ICC). Muscle force, latency and joint angular displacement were compared between groups (facilitated vs. inhibited) using Mann-Whitney U test. Latency and angular displacement were also compared within groups by paring the participants that presented facilitated gluteus medius in one side and inhibited in the opposite one using the Wilcoxon paired test. For the concurrent validity of the AK-MMT in classifying an inhibited muscle as weak was conducted the receiver operating characteristic curve (ROC curve), by using as the test variable the strength test obtained with the dynamometer. Results: Intra- and inter-examiner reliability was excellent, with ICC’s > 0.9. When the whole sample was considered there was no significant difference in latency, but the Wilcoxon paired test showed a significantly difference delay in latency time of the inhibited muscles (mean 0.10 s vs. 0.18 s, p=0.007) compared to the facilitated gluteus medius. Force and peak force of the inhibited gluteus medius were significantly decreased compared to the facilitated ones. Joint angular displacement was significantly greater in the inhibited group. ROC curve showed an area under the curve of 0.743, demonstrating that the classification of the most experienced examiner discriminated the force between groups (p=0.001), which means that the test has concurrent validity. Conclusion: The results have demonstrated that AK-MMT has good clinimetric properties and support the hypothesis that the AK-MMT is sensitive to differences in strength and latency. This means that physical therapists have now a tool to identify neuromuscular dysfunctions that is reliable, valid and easy to be applied in clinical environment. In addition to providing information about the strength and quality of muscle contraction, the use of TMM AK can facilitate the development of therapeutic strategies aimed at correcting motor control dysfunctions, commonly overlooked in the treatment of acute pain and degenerative musculoskeletal disorders.