Reliability and validity of Camry dynamometer for isometric hand grip strength measurement in healthy Indian adults

The Jamar dynamometer is the gold standard to assess hand grip strength, but is expensive. The Camry dynamometer is relatively cost-effective. There is a dearth of literature on Camry's validation in healthy Indian adults, which is important to establish as hand grip is known to vary with age, gender and race.

To establish the reliability and validity of the Camry dynamometer in comparison to the Jamar handheld dynamometer among healthy Indian adults in the age group of 20-59 years.

Following basic demographics, occupation and hand dominance, three trials of each dynamometer were performed in standardised positions for the non-dominant and dominant hand of each participant and the best value was recorded. A gap of 10 min was provided between the 2 dynamometers. Data was then recorded and analyzed.

120 participants were recruited, with an equal males and females. The mean isometric hand grip strength for the non-dominant hand was 26.71 ± 9.29 kgf, and for the dominant hand was 27.66 ± 9.12 kgf using the Camry hand-held dynamometer, while it was 26.43 ± 9.07 kgf for the non-dominant and 27.37 ± 9.26 kgf for the dominant side using the Jamar Hand Held dynamometer. Data was further analyzed with age and gender stratification. The Camry hand-held device had excellent reliability (ICC>0.97) and good validity with Pearson's correlation index of 0.97 (p < 0.05) for the dominant hand and 0.99 (p < 0.05) for the nondominant hand, and Bland-Altman's graphics showing more than 90 % of measures within confidence limits.

Camry digital dynamometer is a reliable and valid device to measure isometric handgrip strength in healthy Indian adults compared to the Jamar hydraulic handgrip dynamometer.