New parameters of hand grip in rheumatoid arthritis patients based on electrodynamic measurements – a pilot evaluation study

Introduction: in rheumatoid arthritis, inflammation and damage lead to functional impairment. as the hand is a typical site of involvement, lower grip strength is often found in patients with rheumatoid arthritis. in these patients it is necessary to evaluate the hand grip impairment in a more detailed way. The aim of this study was to analyze a new method for measuring hand grip. Methods: an expert electronic measuring system for obtaining dynamic time series of hand grip force was developed. We tested it in a sample of 24 participants, 12 patients with rheumatoid arthritis and 12 ageand sex-matched healthy controls. The main dynamometric parameters obtained were: maximum grip force, fatigue, grip velocity, and functional potential. These were measured at the baseline and at 60, 120, and 180 days. Results: compared to the control group, at baseline the patients with rheumatoid arthritis had a significantly lower maximum grip force (68.2 vs. 97.3), earlier occurrence of fatigue (22.4 vs. 24.9), as well as lower grip velocity (14.8 vs. 22.2) and functional potential (808.2 vs. 1876.3). a significant improvement in all measured variables was observed during the follow-up period. Conclusion: in our pilot study we tested a newly developed electrodynamometer measuring system and found that it can provide an objective and detailed description of the hand condition. This system has the potential to be used as a relevant indicator of hand function in patients with rheumatoid arthritis as well as to help tailor their rehabilitation.