Comparison of the Grip Strength Using the Martin-Vigorimeter and the JAMAR-Dynamometer: Establishment of Normal Values

Abstract

Background/Aim: The JAMAR-Dynamometer and the Martin-Vigorimeter are frequently used tools in a hand surgeon's daily routine. This survey is primarily concerned with the establishment of valid conversion factors for measured values of both instruments, as well as the investigation of influence of anatomical characteristics and age and sex on maximal measured grip strength. Patients and Methods: We registered anamnestic data and specific anatomical conditions in 339 patients, maximal grip strength was measured using all notches of both instruments. Results: We found moderate to very high correlation comparing all 28 settings in both instruments. The influence of the hand's anatomy on the grip strength was greater using the JAMAR-Dynamometer than it was using the Martin-Vigorimeter. Conclusion: The high reproducibility allowed us to calculate multiplying factors for the conversion of measured data for all settings of both tools. Therefore, the amount of data for meta-analyses relating to hand surgical issues can be significantly increased.