Comparison of two electronic dynamometers for measuring handgrip strength

Introduction: Handgrip strength (HGS) is a strong predictor and easily applicable assessment, indicating a person's physical condition and health. However, many dynamometers are available; therefore, it is essential to ensure that the results of HGS testing using different dynamometers can be used interchangeably. The primary purpose of this study was to investigate the inter-instrument agreement and criterion validity of the Baseline BIMS Digital Grip Dynamometer in comparison with the Jamar electronic dynamometer (Jamar+). Methods: Seventy participants, aged between 23–88 (five men and five women in each decade from 20 to 80+), performed three attempts with each dynamometer (30-sec break between attempts) in a randomized order and separated with a 5-minute break between dynamometers. Intraclass correlation coefficient (3.1), standard error of measurement and minimal detectable change were used for comparison of the strongest and average strength measured with dynamometers. Jamar+ and Baseline BIMS Digital Grip Dynamometer were new dynamometers and considered calibrated by the manufacturer. Results: The overall Intraclass correlation coefficient was excellent (0.98). An average (SD) difference of 0.68 (2.2) kg (p = 0.04) was seen for the comparison of the strongest attempt for Baseline BIMS minus Jamar+, Correspondingly, for the average of three attempts, it was 0.37 (2.29, p = 0.2) kg. The standard error of measurement (%) and minimal detectable change (%) of the strongest attempt was 1.64 kg (4.2%) and 3.55 kg (9.0%), respectively. Conclusions: Findings indicate low measurement error with high agreement and criterion validity for the comparison of Baseline BIMS Digital Grip Dynamometer and Jamar+ and that results of the two dynamometers can be used interchangeably.