Evaluation of grip strength with a sustained maximal isometric contraction for 6 and 10 seconds.

The grip strength in which subjects sustained a maximal isometric contraction for 6 seconds (the 6-second test) was compared with that for 10 seconds (the 10-second test) to clarify a reliable sustained grip strength test procedure. Fifty healthy students (22+/-4 years, 25 men and 25 women) participated in this study. Strength was measured continuously by the Dexter (Cedaron Medical Inc.). The maximal grip strength, the peak time, and the momentary strength every second during a trial were evaluated. For both tests, the reliable maximal strength and a typical strength-time curve consisting of an early peak time and a decrease in the strength after the peak gradually over time were obtained. In the 6-second test, the momentary strength after 5 seconds that was 82+/-10 approximately 87+/-7% of the peak strength showed good reliability. This variable may be effective in assessing the ability to sustain maximal grip strength.