2007, Piran, Slovenia

Sweating
SWEATY HANDS: DIFFERENCES IN SWEAT SECRETION FROM
PALMAR AND DORSAL SURFACES.
Christiano A. Machado-Moreira 1 , Joanne N. Caldwell 1 , Igor B. Mekjavic 2 ,
Nigel A.S. Taylor 1
1 Human Performance Laboratories, University of Wollongong, Wollongong, Australia and
2 Jozef Stefan Institute, Ljubljana, Slovenia.
Contact person: nigel_taylor@uow.edu.au
INTRODUCTION
The hand is one of the most closely studied body segments with respect to sweat secretion,
with previous research focussing on its neural control, secretion differences between glabrous
and non-glabrous (hairy) skin surfaces, and upon the impact of thermal and non-thermal
stimuli on sudomotor function. It is generally considered that the glabrous palmar surfaces are
adrenergically activated during times of mental or emotional stress, while the non-glabrous
dorsal surfaces are cholinergically innervated, and respond to thermal stimuli (Wolf and
Maibach, 1974). However, surprisingly little is known concerning the regional distribution of
sweating within the palmar and dorsal surfaces of the hand. Therefore, in this project, we
investigated the distribution of sweating within the hand, and measured sweat rates from ten
sites on the dorsal and palmar surfaces during mild hyperthermia.
METHODS
Ten healthy and physically-active adults, 5 males and 5 females (25.8 SD 2.6 y; 70.9 SD 8.8
kg; 176.4 SD 8.9 cm), rested for 40 min in a heated, climate-controlled chamber (36 o C, 60%
relative humidity), whilst wearing a whole-body, water-perfusion suit (Cool Tubesuit, Med-
Eng, Ottawa, Canada) perfused with water at 40 o C. Subjects then performed semi-recumbent,
incremental cycling (increasing from 50 W by 25-W steps every 15 min). Trials were
terminated when core temperature exceeded 39.5 o C for 2 min (N=1) or at volitional fatigue
(N=9). The average exercise duration was 61.2 min (range: 45-75 min).
Local sweat rates were measured using ventilated sweat capsules (1.40 and 3.16 cm 2 )
positioned at the forehead (reference) and at ten sites of the left hand, distributed across the
palmar and dorsal skin surfaces (Figure 1; Clinical Engineering Solutions, NSW, Australia).
Palmar sites: palm (centre), thumb (distal phalanx); index finger (proximal phalanx), middle
finger (distal phalanx) and little finger (middle phalanx). Dorsal sites: dorsal hand (over the
2 nd , 3 rd and 4 th metacarpal bones), thumb (distal phalanx), index finger (distal phalanx),
middle finger (proximal phalanx) and little (middle phalanx).
Only six sweat rates could be recorded simultaneously, so the five remaining capsules were
ventilated with room air to sustain a dry skin surface. During rest, only six sites were
investigated, while during exercise, capsules were connected to the sweat system in a rotating
pattern, leaving one capsule always connected (palm). To control this pattern, two trial
sequences were established, with five subjects participating in each sequence. Subsequently, 5
min prior to each work rate increase, sites of sweat measurement were changed so that the
five remaining sites were now connected to the sweat system. Changes were performed
manually, and were completed within 2 min. This rotation pattern was then continued until
the trial terminated.
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