Clinimetric Properties of the Applied Kinesiology Manual Muscle Test in Adults With and Without Pain: A Methodological Study

Objective

The purpose of this study was to determine the intra- and interexaminer reliability, concurrent validity, and responsiveness of the applied kinesiology manual muscle test (AK-MMT) to discriminate gluteus medius muscle strength and latency.

Methods

A cross-sectional and methodological study was conducted in 38 participants using electromyography, electrogoniometry, and hand-held dynamometry to measure latency, angular displacement, and muscle force during the assessment of the gluteus medius by AK-MMT. Inter- and intrarater reliability of 2 examiners with different levels of experience were obtained using the intraclass correlation coefficient. Muscle force, latency, and joint angular displacement were compared between groups (facilitated vs inhibited). Latency and angular displacement also were compared within groups by using the Wilcoxon paired test. For the concurrent validity of the AK-MMT in classifying an inhibited muscle as weak, the receiver operating characteristic curve was conducted.

Results

Intra- and interexaminer reliability for the facilitated vs inhibited classifications based on AK-MMT presented good results, with intraclass correlation coefficient > 0.86. For the inhibited group, force and peak force were significantly lower and joint displacement significantly greater. The receiver operating characteristic curve showed an area under the curve of 0.743, demonstrating that the test has concurrent validity (P = .001) to discriminate muscle force. The Wilcoxon paired test showed a significant delay in latency of the inhibited gluteus medius group (0.10 s vs 0.18 s, P = .007) when compared with the facilitated one.

Conclusion

In this study, we found good intra- and interexaminer reliability and concurrent validity for the AK-MMT to determine differences in gluteus medius muscle force. Although the paired data showed a different latency time between groups, the hypothesis of prolonged latency in muscles classified as inhibited by AK-MMT still needs further investigation.