Unversty of Nebraska - Lncoln DgtalCommo@Unversty of Nebraska - Lncoln Industral and Management Systems Engneerng Faculty Publcato Industral and Management Systems Engneerng 1995 The effects of extra vehcular actvty (EVA) gloves on human performance Ram R. Bshu Unversty of Nebraska-Lncoln Glenn Klute NASA Follow ths and addtonal works at: http://dgtalcommo.unl.edu/msefacpub Bshu, Ram R. and Klute, Glenn, "The effects of extra vehcular actvty (EVA) gloves on human performance" (1995). Industral and Management Systems Engneerng Faculty Publcato. 75. http://dgtalcommo.unl.edu/msefacpub/75 Ths Artcle s brought to you for free and open access by the Industral and Management Systems Engneerng at DgtalCommo@Unversty of Nebraska - Lncoln. It has been accepted for ncluson n Industral and Management Systems Engneerng Faculty Publcato by an authorzed admnstrator of DgtalCommo@Unversty of Nebraska - Lncoln.
ELSEVIER Internatonal Journal of Industral Ergonomcs 16 (1995) 165-174... Industral Ergonomcs The effects of extra vehcular actvty (EVA) gloves on human performance Ram R. Bshu ~''*, Glenn Klute b a Department of Industral Engneerng, Unt'ersty of Nebraska, Lncoln, NE 68588-0518, USA b Anthropometry and Bomechancs Laboratory, NASA, Johon Space Center, Houston. TX, USA Receved 30 June 1993; revsed 5 August 1904 Abstract Human strength and capabltes such as dexterty, manpulablty, and tactle percepton are unque and render the hand as a very versatle, effectve, multpurpose tool. Ths s especally true for unknown mcrogravty envronments such as the EVA envronment. Facltaton of these actvtes, wth smultaneous protecton from the cruel EVA envronment, are the two, often conflctng, objectves of glove desgn. The objectve of ths study was to assess the effects of EVA gloves at dfferent pressures on human hand capabltes. A factoral experment was performed n whch three types of EVA gloves were tested at fve pressure dfferentals. The ndependent varables tested n ths experment were gender, glove type, pressure dfferental, and glove make. Sx subjects partcpated n an experment n whch a number of dexterty measures such as tme to te a rope, and the tme to assemble a nut and bolt, were recorded. Tactlty was measured through a two-pont dscrmnaton test. The results ndcate that (a) Wth EVA gloves there s a coderable reducton n both strength and dexterty performance; and (b) performance decrements ncrease wth ncreasng pressure dfferental. Some nterestng gender glove nteracto were observed, some of whch may have been due to the extent (or lack of) ft of the glove to the hand. The mplcato for the desgner are dscussed. Relevance to ndustry Gloves are used almost n all the ndustres as a safety devce to protect the human hand. However. performancc s reduced wth gloves. Ths study attempts to lnk glove attrbutes to performance of gloved hand. Hence t s very relevant to the ndustry. Keywords." Strength; Dexterty; Tactlty; Gloves 1. Introducton ~' Ths work has been presented n parts at the Internatonal Ergonomcs and Safety Conference held n Copenhagen, Denmark n June 1993, and at the Annual Conference of the Human Factors and Ergonomcs Socety held n Seattle, USA n October 1993. * Correspondng author. Human capabltes such as dexterty, manpulablty, and tactle percepton are unque and render the hand as a very versatle, effectve, multpurpose tool. Ths s especally true for EVA mcrogravty envronment. Under these cond- 0169-8141/95/$09.50 1995 Elsever Scence B.V. All rghts reserved SSDI 0169-8141(95)00077-8
166 R.R. Bshu, G. Klute / Internatonal Journal of Industral Ergonomcs 16 (1995) 165-174 to the hand becomes the prmary mea of locomoton, restrant and materal handlng. Facltaton of these actvtes, wth smultaneous protecton from the hazards of the EVA envronment, are often conflctng objectves of glove desgn. The conflcts assocated wth provdng prmary hand protecton through the use of a glove whle permttng adequate hand functonng have been wdely recognzed. Numerous artcles have been publshed n the area of the effect of gloves on task performance. Lyman and Groth (1958) reported that when gloves were worn, subjects exerted more force than when barehanded whle ertng p nto a pegbox. Bradley (1969) studed the operaton tme of fve types of control tasks wth bare hand, wool gloves, and leather over wool gloves. The results of hs research showed that the operaton tme depends on the type of gloves, the type of control operato, and the physcal characterstcs of the controls. Cochran et al. (1986) studed grasp force degradaton of some commercally avalable gloves. Fve types of gloves and bare hand condto were compared and the results showed that all the gloves tested reduced the maxmum grasp force sgnfcantly when compared to bare hand condton. Wang et al. (1987) also found smlar results. The basc overall fndngs of these studes are (a) gloves reduce strength capabltes, and (b) gloves reduce dexterty and manpulablty. Whle most of the studes have addressed performance compromses wth commercal gloves, very few studes have attempted to assess the effects of EVA gloves on basc hand capabltes. Perhaps the most compreheve study performed on the assessment of performance decrements wth EVA gloves s the one done by O'Hara et al. (1988). The authors had studed two levels of hand condto (gloved and barehanded), two levels of pressure dfferental (0 psd, and 4.3 psd), and three levels of hand sze (small, medum, and large). The salent fndngs were: (a) Gloves reduced basc hand grp strength, and the pressure dfferental reduced t further; however, nether the glove nor the pressure had any effect on pnch strength; (b) the degradaton n tactle percepton was more notceable wth glove use than wth pressure change; and (c) dexterty was reduced by both glove and pressure. Unpressurzed glove reduced dexterty by 50%, whle pressurzng reduced t further by 30%. The ratonale for ths nvestgaton evolved out of the above study. The O'Hara (1988) nvestgaton used one type of glove and one pressure level. It s recognzed that n EVA tasks the prebreath tme before donnng the sut s a functon of the pressure. Prebreathng s an actvty performed pror to donnng the space sut for EVA actvtes. The purpose of prebreathng s to let the body acheve new physologcal homeostass for actvtes at new, lower pressure. The greater the pressure, the shorter the prebreathng tme. However, the performance decrement s also a functon of pressure, wth larger decrements at greater pressure. An mportant pece of nformaton that s needed, and whch s currently unavalable, s the pressure performance profle for the varous EVA gloves. Therefore, the objectve was to develop functonal relato between performance decrements and pressure dfferental for EVA gloves. 2. Methods 2.1. Subjects Sx subjects (three males and three females) partcpated n ths experment. Ther partcpaton was voluntary. 2.2. Independent varables The ndependent varables tested n ths experment were gender, glove type, pressure dfferental, and glove confgurato. The sx subjects were equally splt between two genders to provde the gender dfferences. Two types of glove assembly were used: wth and wthout thermal mcrometeorte garment (TMG). An EVA glove s an assemblage of two major unts: an nner pressurzng glove and an outer TMG glove. One of the objectves was to assess the exact effect of TMG on performance. Current Shuttle gloves operate at 4.3 psd. Certan developmental gloves are beng desgned to operate at 8.3 psd. The
R.R. Bshu, G. Klute / Internatonal Journal of Industral Ergonomcs 16 (1995) 165-174 167 ratonale beng that operatng at hgher pressure dfferentals results n the pre-breathng tme beng reduced coderably. Fve levels of pressure dfferentals were used n ths experment: 0 psd, 3.2 psd, 4.3 psd, 6.3 psd, and 8.3 psd. The ntent was to develop a pressure-performance decrement profle. Three dfferent glove confgurato were tested here: current Shuttle 3000 seres WETF tranng gloves (referred to hereafter as GLOVE C), and two advanced developmental gloves (referred to hereafter as GLOVES A and B). To summarze, the ndependent varables wth ther respectve levels were: (1) Gender (2) Glove type (3) Pressure (4) Glove confguraton 2.3. Performance measures male and female wth and wthout TMG 0, 3.2, 4.3, 6.3, 8.3 A, B, and C The performance measures were selected based on the O'Hara (1988) study, and comprsed two strength measures (grp and pulp pnch strength), two dexterty measures (nuts-bolts test and rope tyng test), and a tactlty measure (twopont dscrmnaton test). The crtera for selecton of performance measures were (a) they should be generc, and hence repeatable, and (b) they should be reasonably representatve of the EVA actvtes. The grp strength was measured by a standard JAMAR hand dynamometer. The dynamometer was wred to a dgtal dsplay, whch gave the grp strength readngs n pounds. The grp span of the hand dynamometer was kept cotant throughout the experment at 2 nches. The pnch strength was measured by a B & L (60 pounds) pnch gauge. Dexterty and manpulablty were measured by the rope-tyng test and the nuts-bolts test. The former costed of pushng a rope through a hole on a wooden panel and tyng a shoe lace knot around the panel. In order to gauge the sze effect, rope of three szes (small, medum, and large) was used. The tme to te the knot was recorded as a performance measure. The wooden panel had three holes through whch three pars of nuts and bolts (small, medum, and large) were assembled. The nuts and bolts assembly task costed of undong the nut from the assembly, showng the nut and bolt to the test expermenter, and reassemblng the nut and bolt on the wooden panel. The mean assembly tme was recorded and used as a measure of dexterty. The fnal measure recorded n ths experment was the performance n the modfed two-pont dscrmnaton test. O'Hara et al. (1988) had used a modfed verson of a two-pont dscrmnaton (2PD) test for assessng the tactle setvty of subjects under dfferent test condto. A smlar apparatus was fabrcated here to measure the tactle setvty. In essence the apparatus costed of a "V" block through whch the subjects had to slde ther fngers. The "V" block was graduated, and the dstance from the startng end to the pont where the subjects could feel two edges was treated as the tactlty score. As the force wth whch the subjects could press the "V" block was an uncontrollable varable whch could nfluence the results, the "V" block desgn used by O'Hara et al. (1988) was modfed to have a balancng weght on the undersde of the apparatus. The dead weght was expected to facltate cotant applcaton of force on the "V" block durng the admnstraton of the two-pont dscrmnaton test. 2.4. Glove box The testng was done n Advanced Sut Laboratory. The actual tests were conducted de a glove box (Fg. 1). The glove box s cylndrcal n shape, approxmately 2 ft n dameter and 4 ft n length wth an nternal volume of 13 ft 3. On each sde of the glove box were two end caps, made of Plexglas and bolted through 8 bolts. About mdway along the axs of the glove box were 2 sx n. crcular openngs n the cylnder wall, placed shoulder wdth apart, whch provded access and attachment pont for the EVA glove and arm assembles. The glove box was connected to a vacuum pump and could be evacuated to the desred pressure level. There was a gauge on the outer cylnder wall calbrated to read the pressure dfferental.
168 R.R. Bshu, G. Klute / Internatonal Journal of Industral Ergonomcs 16 (1995) 165-174 2.5. Procedure Table 1 Expermental desgn The levels of ndependent varables were fac- Pressure A A wth B B wth C C wth torally combned to yeld 26 expermental cond- TMG TMG TMG to. There were 26 expermental condto n 0 psd ths experment (see Table 1). The order of pre- 3.2 ~ u," ~ 1,," ~ u," sentaton of these was randomzed for each sub- psd 4.3 ject. In addton, all the subjects performed a psd ~,, ~ ~ ~ ~ ~,I 'Bare-handed' condton on the last day. Wthn a 6.3 ~,, tt t,j ~ NA NA condton the order of presentaton of the fve psd tasks (grp, pnch, nuts-bolts, rope tyng, and 2PD 8.3 ~" ~ ~ ~ NA NA test) was also randomzed for each subject. As psd stated earler sx subjects partcpated n ths study. Gender was a between-subject factor. Each subject performed one condton per day, resultng n 26 days of expermentaton n all. A tral costed of the followng steps. (1) The glove box was pressurzed to the requred level. (2) The subject donned a par of comfort gloves and the EVA gloves for that day's tral. Fg. 1. Expermental set-up.
R.R. Bshu, G. Klute /Internatonal Journal of Industral Ergonomcs 16 (1995) 165-174 169 (3) Grp strength was recorded through a Jamar Hand Dynamometer connected to a dgtal dsplay and to a Teac Recorder. (4) Pulp pnch strength was measured followng a 2-mnute rest perod usng a pnch gauge. (5) For the nuts-bolts test, three pars of nuts and bolts (large, medum, and small sze) were mounted on a wooden panel. The task nvolved removng the nut from ts respectve bolt, and mountng the nut back agan. The tme for ths actvty was recorded wth a stop watch. (6) The rope-tyng test costed of tyng a smple shoe lace knot on the same wooden panel that had the nuts and bolts. Three szes of ropes (small, medum, and large) were used and the tme to te was recorded wth a stop watch. (7) 2 PD test costed of the subjects sldng ther rght ndex fnger along the edges of the "V block". The dstance of the pont at whch they felt two edges from ther startng pont was recorded as ther tactlty score. In order to keep the force at the pont of contact cotant the "V block" had a balancng weght on the other sde. Fg. 1 shows the sketch of the expermental set-up wth nuts-bolts panel. Fg. 2 shows the sketch of the three gloves tested. A tral lasted for about 20 mnutes. Further detals of ths procedure are descrbed n Bshu and Klute (1993). For purposes of clarty the data was analyzed frst wth strength as dependent measure, and then wth dexterty measures as dependent varables. 3. Results Ths study had a number of performance measures. The results wll be presented under two headngs: strength as performance measure and dexterty as performance measures, 3.1. Strength as dependent ~,arable The data on grp strength and pnch strength was subjected to an analyss of varance (ANOVA) and Table 2 shows the ANOVA summary. It s seen that all the man factors are sgnfcant for pulp pnch strength, whle glove type (TMG or NO TMG) effect s not sgnfcant for grp strength. Female subjects exhbted lower strengths than ther male counterparts as shown n Table 3, whch shows the average strength across the three pars of gloves tested. Ths result s costent wth the general fndngs that female strength capabltes are about 60-70% of male capabltes. Fg. 3 shows the plot of Glove effect on strength. Compared to bare hand capabltes, there s a 50% reducton n grp strength when gloves are donned. The correspondng reducton n pnch strength s very small (approxmately 10%). The gender dfference s somewhat costent across all the gloves. Fg. 4 shows the plot of Fg. 2. Dfferent types of gloves test.
1 170 R.R. Bshu, G. Klute / Internatonal Journal of lndustral Ergonomcs 16 (1995) 165-174 Table 2 ANOVA summary on grp and pnch strength Dep. var Gender Glove Glove Pressure Type * Make * Type * Gender * Gender * Gender * make type make pressure pressure make type pressure Grp.............. ** * Pnch............ n * * * * ** **p <0.0001; * *p < 0.001; *p <0.01 Table 3 Gender effect on grp and pnch strengths Strength Male Female Grp 58.84 (18.57) lbs. 36.93 (11.75) lbs. Pnch 17.94 (5.30) lbs. 13.08 (2.79) lbs. (Standard devaton n parentheses) pressure effect on strength. The most nterestng aspect of Fg. 4 s that the gender dfferences appear to dsappear at hgher pressure dfferentals. As expected, performance reduces wth ncreasng pressure dfferental. Strength reducto are large from bare hand to glove condton. It appears that there are two levels of performance decrements wth pressure. Performance at 3.2 and 4.3 ps look smlar whle performance at 6.3 and 8.3 ps appear smlar, and worse than other pressure dfferentals. Fg. 5 shows the plot of Glove * TMG nteracton. Glove C seems to stand out from the other two. TMG seems to reduce strength on Glove C, whle the opposte effect s observed on gloves A, and B. A Gender * TMG nteracton appears to 120 7-_ 601... I 0 0 3.2 4.3 6)3 8)3 B H Pressure, PSI GRIP(MALE) ~ GRIP(FEMALE) PINCH(MALE) ~ PINCH(FEMALE) Fg. 4. Pressure effect on strength. 120 r,o m,.-i 4 e~ 100 80 60 40 20 GLOVE A GLOVE B GLOVE C BARE HAND Glove Make ~GRIP(MALE) [] GRIP(FEMALE) PINCH(MALE) ~ PINCH(FEMALE) Fg. 3. Glove effect on strength.
..... R.R. Bshu, G. Klute /Internatonal Journal of lndustral Ergonomcs 16 (1995) 165-174 171 60T 50........ m ~ " m ~40...... ~!3o:... E /.!!!!! 7o] 60... 50 ~4o 3o 20 10:... ~ E 0 ' -- GLOVE A GLOVE B Glove Make NO TMG [] TMG Fg. 5. Glove * TMG nteracton. GLOVE C 10 0 MALE Gender No TMG [] rmc FEMALE Fg. 6. TMG * gender nteracton. exst (Fg. 6), wth the female strength reducng wth TMG, whle the male strength ncreases wth TMG. Sze and extent of ft may be causng ths result. 3.2. Dexterty measures as dependent varable An analyss of varance (ANOVA) was performed on the data for all the dependent measures. The ANOVA summary s gven n Table 4. It s seen that the Gender effect, Glove effect, TMG effect, and the Pressure effect are sgnfcant for almost all of the dexterty varables, whle there appears to be a sgnfcant Gender and TMG effect for tactlty, as measured by the two-pont dscrmnaton test. Table 5 shows the summary of the Gender effect for the varous dependent measures. It s noted that the female subjects were sgnfcantly slower than the male subjects. Fg. 7 shows the plot of the Glove effect on the mean nut and bolt assembly tme. It s nterestng to note that the performance wth gloves s nearly 5 to 6 tmes slower than barehanded performance. Fg. 8 shows the plot of the pressure effect on the nut and bolt assembly tme. The performance decreases wth ncreasng pressure, and that ncrease s not unform. A sze effect appears to be present wth smaller sze Table 4 Summary of ANOVA for the dexterty measures Effects Small Medum Large nut nut nut and and and bolt bolt bolt Gender * * * * * * * * * Subject......... Glove * * * TMG * * * Ps......... Gender * glove * * * Gender * TMG Gender * ps * * * Glove * TMG.... Glove * ps ** TMG * ps..... Small Medum Large TPD knot knot knot *** *** ~** *** *** **~ ~.. *** **, ~. fls [IS
172 R.R. Bshu, G. Klute / Internatonal Journal of Industral Ergonomcs 16 (1995) 165-174 Table 5 Mean tme for males and females Performance measure Mean tme Mean tme males females Small nut and bolt 65.93 sec. 94.45 sec. assembly tme Medum nut and bolt 54.52 sec. 83.13 sec. assembly tme Large nut and bolt 45.63 sec. 70.24 sec. assembly tme Small knot tyng tme 86.91 sec. 117.28 sec. Medum knot tyng 80.26 sec. 117.28 sec. tme Large knot tyng tme 59.24 sec. 81.91 sec. Two-pont 9.03 11.87 dscrmnaton length E G 120 L 100............ ~= 60 80+ 40 2O I I I I I 0 3.2 4.3 6.3 8.3 Pressure, PSI Large ~ Medum ~ Small Fg. 8. Pressure effect on nuts and bolts assembly tme. I takng longer tme. The Glove effect on the mean knot-tyng tme s shown n Fg. 9. Agan, as n the case of nut and bolt assembly tme, the dfference between gloved performance and barehanded performance s large. Fg. 10 shows the plot of the Pressure effect on the knot-tyng tme. The performance seems to decrease wth ncreasng pressure. The decrease s not unform. Two dstnct patter are seen, one between 0 ps and 3.2 ps, whle the other between 3.2 ps and 8.3 ps. Fg. 11 shows the plot of the Glove * TMG nteracton on the mean medum knot-tyng tme. Gloves A and B appear to be better than Glove C. 120, 80~... X\- \\ I 20 I I I A B C Bare Hand Glove Type Large ~ Medum ~ Small,4o! Fg. 9. Glove effect on knot-tyng tme. 2!..., 120, - ],oo+ N40~... 20... ' I0 I I I A B C Bare Hand Glove Type Laa'ge ~ Medum ~ Small Fg. 7. Glove effect on nuts and bolts assembly tme. 6o + dol I I I 0 3.2 4.3 6.3 Pressure, PSI Large ~ Medum ~ Small Fg. 10. Pressure effect on knot-tyng tme. I 8.3
R.R. Bshu, G. Klute / Internatonal Journal of Industral Ergonomcs 16 (1995) 165-174 173 12(I ~ -...... 100.... ~............. 80- ~..... Y~ = 60'....... 40;.......... 20......................... 0 I NOTMG TMG Glove Type GLOVE A ~ GLOVE B ~ GLOVE C Fg. 11. Ghwe * TMG nteracton on medum knot-tyng tme. 3.3. Two-pont dscrmnaton test results An nterestng fndng of ths nvestgaton was that whle tactle performance decreased wth TMG, performance n knot-tyng and nut-bolt assembly tasks mproved wth TMG. Ether the two-pont dscrmnaton test was nadequate, or there s somethng more to the relatohp between tactlty and dexterty than what was beng measured through a 2PD test here. 4. Dscusson and concluson The Gender effect was perhaps the most costent fndng of ths experment. Female subjects tended to perform slower, and showed lower strength capabltes. Tables 2 and 5 show the mean tme for male and female subjects for the dfferent dependent measures. The next major fndng of ths experment s that both pressure and glove reduce performance. It s also apparent that gender dfferences are more defned based on both bare-handed and gloved condto at zero ps dfferental, than at other condto. These fndngs are costent wth those reported by O'Hara et al. (1988) and others (Wang et al., 1987; Cochran et al., 1986). Wth gloves there s an apparent ncrease n grp span, and an earler pressng of fngers wth each other. The former should ncrease the grp strength, whle the latter should reduce the strength. It appears that the effects of ncrease n grp span wth gloves s somewhat counteracted by the reducton n the nter-dgtal movements and range of moton when gloves are donned, resultng n net reducton n performance. Some of the observed gender dfferences may also have been due to lack of ft between hand and glove. Lack of glove effect on pnch strength s costent wth the results reported by Hallbeck and McMulln (1991). As the ponts of applcaton of pnch force are at the tps of dgts 1, 2 and 3 a glove effect was not expected. In fact gloves may even ncrease pnch force due to the extra cushonng provded at the pont of contact. The reduced performance on dexterty measures wth gloves s perhaps due to reduced range of moton and tactle setvty. Wth gloves one would expect reduced nter-dgtal movements, range of moton, and tactle setvty. These were perhaps causng the observed performance decrements. Although the performance wth gloves was reduced as compared to the barehanded condton, the respectve performances among the three gloves tested were comparable. An nterestng fndng of ths nvestgaton was that whle tactle performance decreased wth TMG, performance n knot-tyng and nut-bolt assembly tasks mproved wth TMG. Ether the 2PD test was nadequate, or there s somethng more to the relatohp between tactlty and dexterty than what was beng measured through a 2PD test here. One of the objectves of ths experment was to perform a comparson of the three gloves, wth and wthout TMG. An explanaton for TMG s n order here. Space Shuttle gloves have two components, an nner glove whch has all the hardware for pressurzaton, and an outer glove to protect the wearer from the harsh thermal mcrometeorod envronment of the outer space. The outer glove s called TMG, and was one of the factors nvestgated here. A possble glove * TMG nteracton can have some nterestng mplcato for the desgners. The TMG of glove B appears to be the best, whle that of glove C s the worst. The results suggest that n case of glove C TMG does
174 R.R. Bshu, G. Klute / Internatonal Journal of lndustral Ergonomcs 16 (1995) 165-174 not change the performance level, whle t does offer the needed protecton. However, the TMG of gloves B, and A, n addton to the provdng protecton agat envronment seem to mprove performance as well. Overall, glove B seems to be the best. Its TMG shows the best performance mprovement, and t has the best strength performance at all the pressure dfferental. Its dexterty performance, however, was comparable to that of glove A, and much better than glove C. Glove B has a metacarpal jont as part of ts desgn feature. Perhaps t s ths dfference that s causng t to perform best. More nvestgaton s needed on ths ssue. There were some other nterestng nteracto as well n ths experment. Male subjects' performance mproved n the order A, B, and C, whle female subjects' performance mproved n the opposte order C, B, and A. In summary, t s seen that wth gloves strength s reduced by nearly 50%. Further performance decrements occur wth ncreasng pressure dfferental, and TMG effects are not costent across the three gloves tested. Sze was not controlled n ths study and may have had an mpact on the fndngs. More research s needed to determne the exact effects of sze and glove materal on performance. Such a data wll be nvaluable to the desgner of hand gloves. References Bshu, R.R. and Klute, G., 1993. Investgaton of the effects of extra vehcular actvty (EVA) gloves on performance. NASA Techncal Paper no. 3401, Johon Space Center, NASA, Houston, Texas. Bradley, J.V., 1969a. Effect of gloves on control operaton tme. Human Factors, 11: 13-20. Cochran, D.J., Albn, T.J., Bshu, R.R. and Rley, M.W., 1986. An analyss of grasp force degradaton wth commercally avalable gloves. Proceedngs of the 30th Annual Meetng of the Human Factors Socety, 852-855. Hallbeck, M.S. and McMulln, D., 1991. The effect of gloves, wrst poston, and age on peak three-jaw pnch force: A plot study. In the Proceedngs of the 35th Annual Meetng of the Human Factors Socety, Santa Monca, CA, pp. 753-757. Lyman, J., and Groth, H., 1958. Preheon force as a measure of psychomotor skll for bare and gloved hands. Journal of Appled Psychology, 42 (1): 18-21. O'Hara, J.M., Brgant, M., Cleland, J. and Wnfeld, D., 1988. Extravehcular Actvtes Lmtato Study. Volume II: Establshment of Physologcal and Performance Crtera for EVA Gloves-Fnal Report (Report number AS- EVALS-FR-8701, NASA Contract no NAS-9-17702. Wang, M.J., Bshu, R.R. and Rodgers, S.H., 1987. Grp strength changes when wearng three types of gloves. Proceedngs of the Ffth Symposum on Human Factors and Industral Desgn n Coumer Products, Interface 87, Rochester, NY.