Muscle fatigue resistance: comparison of Martin vigorimeter and Jamar dynamometer in community-dwelling people

Background: For the diagnosis of frailty exhaustion is a criteria currently measured by self-reported questionnaires, which are subjective and dependent on individual perception. The FR test has been developed as a bed side objective evaluation of muscle fatigue. The test was validated for the VM. However, the JD is frequently used to measure the grip strength. So the comparison of these devices is required to understand if FR is similar when measured with both devices. Methods: Fifty-four (29 female and 25 male; mean age: 39.98 ± 18.09) community-dwelling people were tested for muscle function. The Fatigue resistance (FR), which is the time during that grip strength drops to 50% of its maximum, was recorded with each device and simultaneous sEMG of the forearm muscles was obtained. The (co-)activation of agonist and antagonist muscles was calculated and compared with the differences between the performances with each device (controlling for gender and age). Results: FR was significantly better when measured with VM compared to JD. At all phases of the FR-test the antagonist muscle co-activation was significantly higher for VM compared to JD. In contrast, the agonist muscle activation level was significantly higher in JD compared to VM. When performing the FR-test with VM, both the agonist muscle activation and antagonist muscle co-activation decreased significantly (p<0.05). Whereas when using the JD, only a significant decrease in the antagonist muscle co-activation was observed. The difference in antagonist muscle activation between VM and JD was significantly related to the difference in FR between both devices. Conclusion: The results suggest that the FR-test when using the VM induces a more prominent muscle exhaustion than when using the JD, which makes the VM more suitable for measuring muscle fatigue resistance. However, these findings must be confirmed in a larger study population.