Validity and reliability of Bluetooth-enabled smart hand dynamometer to measure hand grip strength and pinch strength in healthy young individuals

Objective This article describes a study aiming to establish the concurrent validity and intra-rater reliability of the Bluetooth-enabled smart hand dynamometer (BESHD) to measure the handgrip strength and pinch strength in healthy young individuals. Subjects and Methods Grip strength testing was performed on 110 healthy participants. Three trials were undertaken for both the dominant and non-dominant hand using a BESHD and a Jamar dynamometer as well as a pinch meter, with 1 min of rest in between the trials and 3–5 min of break in between each piece of measuring equipment. The maximum reading was considered the best score. Results Validity was determined by the Bland-Altman plot method, and intra-rater reliability was confirmed by the intraclass correlation coefficient (ICC). Mean and standard deviation of the Jamar dynamometer showed higher hand grip strength than the BESHD in the dominant hand (11.31 ± 4.59) and non-dominant hand (10.84 ± 4.67). The BESHD showed higher pinch strength of the index, middle, ring and little fingers than the pinch meter in the dominant hand, whereas, in the non-dominant hand, pinch strength of the index finger measured with the BESHD was lower than with the pinch meter and higher pinch strength of the middle, ring and little fingers were observed. The ICC of the BESHD for hand grip strength was higher in the dominant (0.904) than the non-dominant (0.861) hand. The ICC for pinch grip strength of the I–IV fingers in the dominant and non-dominant hands ranged from 0.724 to 0.887. Conclusions BESHD is valid and reliable in measuring the handgrip strength and pinch strength, and thus, can be used in clinical settings for the patients.