Mobility of the Elastic Counterpressure Space Suit Glove

Abstract

To evaluate the mobility of the current gas-pressurized glove of the extravehicular mobility unit (G-glove) and the elastic counterpressure glove (E-glove), we investigated range of motion (ROM) and indices of fatigue during grip endurance with both gloves using a bare hand as a control. In nine healthy male right-handed subjects, ROM of the proximal interphalangeal joint of the left middle finger was measured. The median frequency of electromyography (EMG) of the left flexor carpi radialis during grip with 25% of maximum strength was measured with the bare hand, G-glove, and E-glove. Using Borg's scale, discomfort was assessed during each grip test. ROM of the E-glove was similar to that of the bare hand (91 +/- 3 degrees and 97 +/- 1 degree for the E-glove and bare hand, respectively) and significantly higher than that of the G-glove (74 +/- 2 degrees). The change in the median frequency of the EMG, which is correlated with Borg's scale, was significantly smaller using the E-glove at marker time points of 1/4 and 1/2 of the total endurance time (-3.5 +/- 1.5 and -10.4 +/- 1.2 Hz) compared to those for the G-glove (-10.1 +/- 1.1 and -16.7 +/- 1.9 Hz). Thus, the G-glove had faster onset of fatigue than the E-glove. These results suggest the E-glove has better mobility and is more suitable for fine motor tasks as compared to the G-glove.