Hand-held compared with isokinetic dynamometry for measurement of static knee extension torque (parallel reliability of dynamometers).

The purpose of this study was to compare measurements of static knee extension torque obtained using a hand-held dynamometer (HHD) and an isokinetic dynamometer (IKD). Twenty young healthy women performed two maximum knee extension efforts against each device. The two HHD measurements did not differ significantly and were highly reliable (intraclass correlation coefficient (ICC) = 0.945). The two IKD measurements did not differ significantly and were highly reliable (ICC = 0.932). The mean of the two HHD and two IKD measurements did not differ significantly. The inter-instrument reliability was fair (ICC = 0.797). Thus, under limited circumstances the instruments may be interchangeable. The less expensive and more portable HHD may be a practical alternative for the clinical measurement of muscle strength.