Gripwise Versus Jamar: The Challenge of a New Dynamometer Assessing Handgrip Strength

Background: Sarcopenia diagnosis is partly based on handgrip strength (HGS) assessment. The gold-standard dynamometer for this measurement is the Jamar. The electronic Gripwise is a smaller and lighter one, and its measurements are correlated with the Jamar's in laboratory tests. Our study aimed to confirm this correlation in aged patients. Methods: This monocenter cross-sectional study was performed in patients of 65 years and older admitted at the University Hospital. Participants were assessed either in a seated or bedridden position, randomly allocated to begin the measurements with the Jamar or the Gripwise. Results: Among 649 aged inpatients assessed for eligibility, 348 were included (mean age: 79 +/- 9; 52% females). The intraclass correlation coefficient was 0.93 (95% confidence interval [CI] 0.92-0.94, p <.001) for the maximum value measured with both devices and 0.94 (95% CI 0.93-0.95, p <.001) for the mean values. However, there was a significant difference in detecting low values (<16 kg in women, <27 kg in men), found in 48% of patients with Jamar, and 71% with Gripwise (p <.001). Thus, we determined alternate cutoffs for diagnosing HGS low values with the Gripwise (<12 kg in women, <22 kg in men), further validated in a supplementary validation population (n = 70). The diagnostic performances of these alternative cutoffs were high (93% sensitivity and 87% specificity in women; 94% sensitivity and 96% specificity in men). Conclusions: The correlation of the Gripwise with the Jamar was confirmed in aged inpatients. However, lower values recorded with the Gripwise require alternate cutoffs for a relevant low HGS diagnosis.