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

Abstract

Background: 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.

Objectives: 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.

Methods: 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.

Results: 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.

Conclusion: 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.