Intra- and inter-tester reliability and reference values for hand strength.

The intra- and inter-tester reliability for measurement of handgrip strength and indexgrip strength using the Jamar dynamometer was investigated in 32 healthy volunteers, and the intra-tester reliability in 13 patients with cervical radiculopathy. The results from the reliability studies showed that handgrip and indexgrip strength measured with the Jamar dynamometer is a reliable method (ICC values 0.85-0.98) and can be recommended for use in clinical practice. Age- and sex-specific reference values for handgrip strength and indexgrip strength were measured with the Jamar dynamometer in 101 randomly selected healthy volunteers, aged 25-64 years. The results from the reference value study showed that sex is a more important determinant of hand strength than age, height and body weight. The reference values for hand strength improve the potential for objective evaluation of patients with arm/hand disorders caused by cervical radiculopathy.