Validity and Intrarater Reliability of the FysioMeter—Measuring Eccentric Knee Flexor Force During the Nordic Hamstring Exercise

Abstract

Between limb strength, asymmetry is a leading risk factor for hamstring strain re-injury. However, few accurate testing methodologies are available in clinical settings. This study examined the validity and reliability of eccentric knee flexor torque measured with a novel Nordic Hamstring Device. Twenty-seven healthy participants were assessed in two sessions. Maximal eccentric knee flexion torque was measured by the Biodex system 4 and during the Nordic Hamstrings Exercise in the FysioMeter. A moderate correlation was found between the FysioMeter and the Biodex (rho 0.674). Limits of agreement showed a bias of −43.9 Nm, suggesting that the FysioMeter underestimated the knee flexor peak torque compared with the Biodex. The FysioMeter showed excellent test–retest reliability (ICC 0.964). In conclusion, the FysioMeter provided moderately valid measures of knee flexor peak torque and excellent test–retest reliability. The FysioMeter could be a valuable tool for guiding rehabilitation in settings where access to isokinetic dynamometry is limited.