Influence of grip types and intensities on force-decreasing curves and physiological responses during sustained muscle contractions

金沢大学人間社会研究域人間科学系福井大学医学部This study examined relationships between force outputs during sustained isometric grips (SIG) and intermittent repeated grips (IRG) with three relative target forces (50%, 75%, and 100% MVC), and subjective muscle-fatigue sensation (SMS) and blood lactate during and after gripping tests. Ten young men performed sustained grip tests with 2 grip types and 3 target forces for 6 min. Lactate and maximal grip strength were measured before, just after and 4 min and 7 min after each grip test. SMS of the forearm was measured every 30 s during and after each grip test. The relationships of average grip force in every 30 s between SIG and IRG were not good. The lactate values after IRG tests with 75% and 100% MVC tended to be higher than in the other conditions. The tendency for decline differs with grip type, intensity (target forces) and the force outputs among the conditions. The muscle fatigue level in the SIG and IRG tests may differ largely even when using the same target force. Although the SIG imposes a larger burden on subjects than the IRG, lactate after gripping work is lower. © Springer-Verlag Italia 2008