Karagiannis, Christos

ObjectiveThe purpose of this study was to evaluate the test-retest reliability of handgrip strength measurement using a hydraulic hand dynamometer in patients with cervical radiculopathy (CR). MethodsA convenience sample of 19 participants (14 men and 5 women; mean ± SD age, 50.5 ± 12 years) with CR was measured using a Jamar hydraulic hand dynamometer by the same rater on 2 different testing sessions with an interval of 7 days between sessions. Data collection procedures followed standardized grip strength testing guidelines established by the American Society of Hand Therapists. During the repeated measures, patients were advised to rest their upper limb in the standardized arm position and encouraged to exert 3 maximum gripping efforts. The mean value of the 3 efforts (measured in kilogram force [Kgf]) was used for data analysis. The intraclass correlation coefficient, SEM, and the Bland-Altman plot were used to estimate test-retest reliability and measurement precision. ResultsGrip strength measurement in CR demonstrated an intraclass correlation coefficient of 0.976, suggesting excellent test-retest reliability. The small SEM in both testing sessions (SEM1, 2.41 Kgf; SEM2, 2.51 Kgf) as well as the narrow width of the 95% limits of agreements (95% limits of agreement, −4.9 to 4.4 Kgf) in the Bland-Altman plot reflected precise measurements of grip strength in both occasions. ConclusionsExcellent test-retest reliability for grip strength measurement was measured in patients with CR, demonstrating that a hydraulic hand dynamometer could be used as an outcome measure for these patients.

ObjectiveThe purpose of this study was to investigate the degree of test-retest reliability of grip strength measurement using a hand dynamometer in patients with shoulder impingement syndrome. MethodsA total of 19 patients (10 women and 9 men; mean ± standard deviation age, 33.2 ± 12.9 years; range 18-59 years) with shoulder impingement syndrome were measured using a hand dynamometer by the same data collector in 2 different testing sessions with a 7-day interval. During each session, patients were encouraged to exert 3 maximal isometric contractions on the affected hand and the mean value of the 3 efforts (measured in kilogram-force [Kgf]) was used for data analysis. The intraclass correlation coefficient (ICC2,1) as well as the standard error of measurement (SEM) and Bland-Altman plot were used to estimate the degree of test-retest reliability and the measurement error, respectively. ResultsGrip strength data analysis revealed an ICC2,1 score of 0.94, which, based on the Shrout classification, is considered as excellent test-retest reliability of grip strength measurement. The small values of SEMs reported in both sessions (SEM1, 2.55 Kgf; SEM2, 2.39 Kgf) and the small width of the 95% limits of agreement in the Bland-Altman plot (ranging from −7.39 Kgf to 7.03 Kgf) reflected the measurement precision and the narrow variation of the differences during the 2 testing sessions. ConclusionsResults from this study identified excellent test-retest reliability of grip strength measurement in shoulder impingement syndrome, indicating its potential use as an outcome measure in clinical practice.