Inter- and intra-examiner reliability of the strength of shoulder rotators in different positions using isometric dynamometry

ABSTRACT The handheld dynamometer is a portable device of easy use in clinical practice. However, its use requires reliability and reproducibility parameters in shoulder positions with and without stabilization. The objective of this study was to evaluate the inter- and intra-examiner reliability of the shoulder rotator strength measurement at 0° and 90° abduction with inexperienced examiners. Twenty subjects (27.05 ± 8.17 years, 76.6 ± 10.97 kg, 1.74 ± 0.07 m) of both sexes and no previous or current complaints of shoulder and neck pain participated in this study. The evaluation of the internal and external shoulder rotators was performed using a handheld dynamometer (MicroFET 2, Hoogan Health Industries, West Jordan, UT, USA) in two positions: sitting with 0° shoulder abduction and supine and with 90° shoulder abduction. Inter- and intra-examiner reliability and reproducibility were assessed through the intraclass correlation coefficient (ICC) considering a 95% confidence interval (p<0.05). There was excellent reproducibility in the intra-examiner analysis and very good levels of reliability measures in the inter-examiner analysis for most variables. The positions of 0° and 90° shoulder abduction showed reliable and reproducible results when using the handheld dynamometer with examiners that had no clinical experience.