Armored 
Medical Research Laboratory 
Fort Knox, Kentucky 
PROJECT No. T-13 " SURVEY OF FOOT MEASUREMENTS AND THE 
PROPER FIT OF ARMY SHOES 
Second Partial Report On 
Study of Sweating of the Feet of Marching Troops 
Project T-13 
4- December 194-5 ARMORED MEDICAL RESEARCH LABORATORY 
Fort Knox, Kentucky 
AMRL Project No, T13 
SCO Project No. 611 
SPMiSA 727.3 
4 December 1945 
10 PROJECT AMRL No, T13. SCO Noa 611 - Survey of Foot Measurements 
and the Proper Fit of Army Shoes; 
Second Partial Report - Study of Sweating of the Feet 
of Marching Troops, 
a. Authority; First Indorsement SPMDO 421,3 - ASF-SGO, Washington, 
Do C0, dated 24 September 1945 
b. Purpose: To obtain factual information pertaining to foot 
sweating with regard to: 
1, The rate and volume of sweat secretion; 
2, The relationship of sweating to foot symptoms; 
3, The water retentive characteristics of service 
shoes and of various types of socks. 
2. DISCUSSION; 
None, 
3o CONCLUSIONS: 
In a temperate zone, summer environment: 
a0 Neither burning of the feet nor the development of blisters 
appears to result from the accumulation of excessive moisture 
within the sock0 
b„ Service shoes, reversed upper, composition sole, whether 
dubbed or not, permit dissipation of only a relatively small 
amount of foot moisture to the exterior atmosphere. 
c. The sweat adsorbed by shoes is predominantly into the shoe- 
upper, despite the fact that the weight ox the leather in 
the sole is greater than that in the upper. Socks, wool, 
light, are not capable of retaining the amount of sweat 
excreted by some men during a warm summer day0 
1 4. R ECOMMENDATIONS: 
None. 
Submitted by: 
Arthur Freedman, Captain, MC 
Charles M0 Kirkpatrick, Tec 3 
' \/l) ' > 
approved UvCdJrzy 3 3 L'W 
WILLIAMS. BEAN 
Major, Medical Corps 
Commanding 
Inc1.-Appendix 
2 APPENDIX 
lo INTRODUCTION; 
The accumulation of sweat inside shoes has been blamed for many of 
the foot disabilities which marching troops suffer. In warm environments, 
in particular, blisters and the sensation of burning of the soles of the 
feet have been attributed to excessive sweating. Furthermore, the presence 
of moisture leads to tissue maceration and provides a favorable environment 
for interdigital fungus growth. It has been asserted also that the application 
of dubbing to shoes increases the retention of sweat, and this practice has 
therefore come to be regarded somewhat unfavorably by troops. In the course 
of other studies on the relationship of shoes to the development of foot casu- 
alties among marching troops, the opportunity was available to subject these 
beliefs to test. 
2. CONDITIONS: 
Troops were marched over a 13®7 mile course, for which the actual 
marching time was 4 hours and 20 minutes, at a rate of 119 paces per minute. 
New service shoes, reversed uoper, composition sole were issued at intervals 
during the test and were worn continuously for an average of 6J hours daily. 
Two short breaks and a longer one for lunch were allowed. The observation 
procedures before and after each march occupied approximately 30 minutes each. 
The use of powder was not permitted. The marching course lay over rolling 
country, one-third on concrete road, one-third on improved dirt and gravel 
road, and one-third on unimproved dirt road. Water and salt were allowed ad 
libitum and were provided in abundant quantity. The troops began marching 
over the established course ten days before any observations on sweating were 
made, and observations were continued throughout 32 days of testing. The men, 
all of whom had been in the Army for a minimum of 8 months prior to their 
arrival at the Laboratory for study, were at least partially conditioned before 
data were collected. Typical Kentucky mid-summer environmental conditions were 
encountered during the test days. The weather data shown in the respective 
tables are for shade conditions and, therefore, are lower than temperatures in 
the sun. The test group used for these studies was chosen at random. 
3® RESULTS r 
a, Amount and Effect of Sweating; 
(1) Moisture was trapped in the sock by inserting a thin boot of 
rubber dam between the sock and the shoe of one foot. By weighing the en- 
closed sock before and after a march, the total amount of accumulated sweat 
was readily determined. The results of one series of observations, shown in 
Table 1, indicate that the sweating rates for one foot for different men may 
vary at least from 2,0 to 8,5 grams per hour, at the temperatures encountered. 
(2) Each subject was interrogated concerning any difference in sen- 
sation between the foot wearing the rubber boot and the one without it, In 
only one instance did the foot wearing the rubber boot seem warmer than the 
other, and in no instance was the sensation of burning of the soles of the 
feet associated with the presence of the rubber boot. Blisters did not develop 
in connection with the increased accumulation of moisture0 
Inclo (3) Some subjects who did report burning of the soles of the feet 
asserted that the burning was not associated with the wearing of the rubber 
boot, but was noted instead during rest periods rather than during actual 
marchingo This suggested that burning may be a manifestation not of sweat 
accumulation, but of the presence of an excess of intercullular fluid in the 
dermis or epidermis appearing as a circulatory phenomenon, in the lower ex- 
tremities of men resting after exercise. Since the volume of such fluid 
would be too little to detect by volume displacement, an attempt was made to 
test for its presence by injecting 0.1 cc of saline intradermally into the 
soles of subjects who noted burning and into the soles of others who did not, 
in the expectation that absorption of the fluid introduced might occur more 
rapidly in one group than in the other. Unfortunately, this proved unsuccess 
ful since it was not possible to produce blebs on the soles of the feet in a 
standard manner, and the thickness of the epidermis interfered with accurate 
assessment of their rate of disappearance. 
TABLE 1 
AMOUNT AND RATS OF FOOT SWEATING OF TROOPS 
MARCHING IN A WARM ENVIRONMENT* 
DAY OF T3ST 24th 25th 
MEAN SHADE D.B. 83°F D0B0 84°F 
TEMPERATURES R0H0 55% R.HC 59% 
NAME 
SWEAT ACCUMULATION 
'(EA1B/64 Hrs.) 
SWEAT ACCUMULATION 
(GRAMS/61 Hrs.) 
MEAN SWEATING RATE 
FOR ONE FOOT 
(GRAMS/Hr) 
Woo 
12e2 
14 e 5 
2.0 
Fir 
15 oO 
25.0 
3.1 
Wea 
209? 
33.8 
4.2 
Voz 
24 .5 
29.5 
4.2 
Buf 
29.0 
32.6 
4.7 
Phi 
35*5 
41.8 
5.9 
Woh 
36.9 
43.2 
6e2 
Sin 
37ol 
29.5 
5.1 
Cru 
54*5 
55.0 
8.5 
Inclo * Sweat was measured as the increase in the sock weight when an impermeable 
boot of thin rubber dam was worn between the sock and shoe on one foot. The 
sweat which adhered to the rubber was fairly constant at 2.0 grams and is not 
included in the above figures. 
b0 Retention of Sweat by Footgear: 
(1) The transmission of sweat by shoes was estimated in a manner 
similar to that described above. Each subject wore the rubber boot between 
his sock and shoe on one foot and omitted it on the other. Both the sock and 
shoe were weighed before and after marching, the shoe being brushed vigorously 
before weighing to remove any dust picked up on the road. The results presented 
in Table 2 show that the shoe on the foot wearing the rubber boot consistently 
lost weight during the march, while the other shoe gained weight, the mean 
weight loss in the one case being 9<>6 grams, and the mean weight gain in the 
other being 9.1 grams. The loss of weight of the shoe containing the rubber 
boot may be attributed to the fact that no moisture was picked up from the foot, 
while some of the intrinsic moisture within the shoe evaporated and some of the 
composition sole wore away. ( The total moisture content of a shoe is approx- 
imately 26 grams. This was determined by drying a new shoe in an oven at 75°C 
for 12 hours to nearly constant weight)„ 
TABLE 2 
DISPOSAL OF SWEAT BY FOOTGEAR 
Comparison Between Changes in Sock and Shoe Weights When Sweat 
is Trapped in Sock and When it is not Trapped 
(Data are in grams) 
CHANGE 
IN 
CHANGE IN 
MEAN 
SHADE 
SOCK 
WEIGHT 
SHOE WEIGHT 
TEMPERATURES 
DAY OF 
D0Bo°F. 
RUBBER BOOT 
RUBBER BOOT 
TEST 
R.H.jS 
SUBJECT 
WORN 
OMITTED 
WORN 
OMITTED 
10 
B5 
60 
Woh 
4 
28,2 
4 
12 08 
- 8.5 
4 5.7 
Bel 
4 
30,6 
4 
6,8 
- 12,7 
4 5.9 
11 
86 
67 
Woh 
4 
31.7 
4 
13.3 
- 7.6 
+ 19.3 
Bel 
+ 
26.3 
+ 
6,9 
- 10.9 
+ 5.9 
12 
88 
64 
Woo 
4 
16,7 
4 
18,7 
- 9,6 
- 1,6 
Voz 
4 
46.9 
4 
20.7 
- 12,1 
+ 14.7 
13 
86 
62 
Woo 
4 
12 c7 
4 
13o8 
- 7.2 
+ 4.5 
Voz 
4 
50,9 
+ 
21o7 
- 8,5 
4 17.5 
MEAN 
4 30o5 
4 
14 o3 
- 9.6 
4 9.1 
Inclo (2) It is possible to derive from these data the percentage of moisture 
retained by the shoe. To do this one must assume that the foot sweats at the same 
rate on two successive days and that the presence of the rubber dam does not alter 
the sweating rate. Table 1 does suggest that the sweating volume is reasonably 
constant on successive days but it was not possible to verify the latter assump- 
tionc Table 3> which is derived from Table 2, compares the sock weight increase 
when the rubber boot is worn with the combined sock and shoe weight when the 
rubber boot is not worn, both for the same foot on successive days and for the 
opposite foot on the same day0 
TABLE 3 
RETdNTION OF SWEAT BY SHOE AND SOCK 
SUBJECT 
AMOUNT OF 
FOOT SWEATING* 
(Grams) 
INCREASE IN 
TOTAL SHOE 
AND SOCk WEIGHT** 
(Grams) 
PROPORTION OF 
ranma 
BY SHOE AND SOCK 
Woh 
28 o 2 
18.5 
65.6* 
Bel 
30.6 
12o7 
41.5* 
Woh 
31o7 
33*1 
104.5* 
Bel 
26 o 3 
12,8 
48.5* 
Woo 
16.7 
17.1 
102.5* 
Voz 
46.9 
35.4 
75.5* 
Woo 
12o? 
18,3 
144.0* 
Voz 
50.9 
39 o 5 
77.5* 
MEAN 
30 o 5 
23.4 
RATIO OF 
THE MEANS - 
Determined when rubber boot worn as the increase in sock weight0 
‘Determined when rubber boot not wornc 
Inclo 
4 (3) The data, which are only approximations, indicate that a large 
part of the moisture from sweating of the foot actually remains in the shoe 
and the sock and does not get to the outside. In those instances in which the 
shoe and sock actually weighed more than the amount of sweat measured when the 
rubber boot was worn, it is likely that the sweating rates of the feet differed 
during the two tests and that some of the road dirt picked up by the shoes was 
not brushed off0 
(4) Dubbed shoes are compared with undubbed shoes both with regard to 
their own capacity to adsorb moisture and with regard to their influence on the 
accumulation of moisture within the sock0 The dabbing was applied generously 
and worked in well. It is apparent from Table 4 that there is not a great differ- 
ence between the weight increase of the sock or the shoe whether or not dubbing 
is used. Dubbing, therefore, does not appear to affect significantly either the 
permeability of the shoes or their capacity to adsorb moisture from the foot 
surface. 
TABLE 4 
EFFECT OF DUBBING ON THE RETENTION OF SWEAT BY FOOTGEAR 
Comparison of Increase in Sock and Shoe Weight Due to Sweat 
Accumulation when Dubbed and New Undubbed Shoes are Worn0 
(Mean of 4 Subjects)* 
DAY OF TEST 
MEAN 
SHADE 
INCREASE 
IN A SIGHT 
TEMPERATURES 
SOCK 
SHOE 
D.B,°F 
RoH9$ 
(GRAMS) 
(GRAMS) 
28 
71 
77 
Dubbed 
io0o 
9.8 
29 
77 
56 
it 
7.7 
6.2 
30 
77 
46 
n 
7.8 
6o0 
31 
S3 
53 
Undubbed 
9.0** 
9.8 
32 
86 
47 
« 
8.8 
9.2 
*Troops marched 13 <>7 miles and wore their shoes 6g hours 0 
**Mean of 3 subjects only. 
Inclo (5) The relative increase in weight of the sole and upper of the shoe, 
due to moisture accumulation, was estimated by weighing a shoe before and after a 
march, then severing the upper from the sole, weighing again to obtain the com- 
ponent values and finally weighing the shoe halves twelve hours later to determine 
the weight loss of each half as a consequence of equilibration with the atmosphere. 
Table 5 shows the results of such weighings on two different shoes„ 
TABLE 5 
DISTRIBUTION BETWEEN SOLE AND UPPER OF MOISTURE 
ADSORBED BY SHOES DURING MARCHING 
(Data are in Grams) 
SHOE N0.1 
SHOE 
NO.2 
Weight gain of shoe during march 
18oG 
16,0 
Weight loss of upper after 12 hours 
at room temperature 
8,9 
6.9 
Weight loss of sols after 12 hours 
at room temperature 
5.5 
4.8 
Total weight loss due to evaporation 
of accumulated shoe moisture 
14.4 
llo7 
Weight gain not accounted for 
3.6 
4.3 
(6) These figures are interesting inasmuch as the weight of the leather 
upper of the shoe is only 23% of the total weight of the shoe while the weight of 
the leather components of the sole is aoproximately 36%, as shown in Table 6, It 
would appear, therefore, that the upper leather adsorbs a proportionately greater 
part of the sweat of the foot than the sole. To what extent this relates to the 
proportionate sweat production of the various foot surfaces cannot be stated pre- 
cisely. Under certain influences the plantar surface of the foot sweats more 
abundantly than the dorsal but under other influences the reverse is true (1), 
(1) Kuno,Y, - The Physiology of Human Perspiration, J&A Churchill, LTD, London,19340 
Inclo TABLE 6 
WEIGHT OF COMPONENT PARTS OF SHOE 
(Grams) 
NON-LEATHER PORTION OF SOLE; 
Composition outsole 188,5 
Composition heel 124.5 
Metal s hank 1205 
325.5 41$ 
PREDOMINANTLY LEATHER PORTION OF SOLE: 
Midsole and filler 131.5 
Insole,welt, filler 
and canvas 147.5 
279o0 36$ 
LEATHER UPPER: 187.1 23$ 
Total Weight Exclusive of Nails 791.6 100$ 
(7) The moisture retentive capacities of various standard types of 
socks were also determined as a matter of record. Table 7 shows the results when 
6 types of socks were dried in an oven to determine the amount of moisture adsorbed 
from the atmosphere. 
Inclo TABLE 7 
JIOISTURE CONTENT OF SOCKS AT EQUILIBRIUM WITH ATMOSPHERE 
(D0B« 76°F, R.H. 50% Approx.) 
WEIGHT AFTER 
DRYING IN OVEN 
MDISTURE CONTENT 
TYPE OF SOCK 
WEIGHT 
BEFORE DRYING 
FOR 24 HOURS 
AT 50°C 
PSBCSWT OF 
INITIAL WEIGHT 
Wool, light, woven, 0*Do 
33 08 Goiso . 
31.1 
Gins o 
7.9? 
Wool, light, knit, 0eDo 
42=8 » 
38*0 
n 
11.2? 
Cushion sole, 73-531824 
42 c 7 " 
38.9 
n 
8.8? 
Cushion sole, 73-531828 
43.3 " 
37.7 
10.8? 
Wool, heavy, white, 73-532238 
58,4 ” 
53 o 2 
»i 
9.7? 
Wool, ski, 73-534403 
77.3 " 
70,2 
w 
9.1? 
(8). The mates to these socks were then soaked in water to determine 
their maximum adsorptive capacity. After soaking, the socks were allowed to hang 
for 3 hours at room temperature to permit all surface water to drip off* Some 
evaporation undoubtedly occurred during this period since the room conditions were 
approximately 76°F, D.B0, 50% R.H0 The amount of water uptake after soaking is 
shown in Table 80 It is of interest that neither of the socks, wool, light, would 
be capable of retaining the amount of sweat accumulated within the rubber boot in 
only hours in the case of CRU ( Table 1). 
Inclo TABLE 8 
WAT SR UPTAKE OF SOCKS AFTER THOROUGH SOAKING 
WATER CONTENT 
WEIGHT 
WEIGHT 
PERCENT OF 
TYPE OF SOCK 
BEFORE DRYING 
AFTER WETTING 
INITIAL WEIGHT 
Wool, light, woven, 0oDo 
31.5 Gms. 
71o5 Gms. 
126.9? 
Wool, light, knit, 0oD, 
41.9 " 
86.0 " 
105.2? 
Cushion sole - 73-531624 
37.8 " 
97 o7 " 
158.4? 
Cushion sole - 73-531828 
41o9 " 
110o6 " 
163.9? 
Wool, heavy, white - 73- 
532236 60.6 M 
139o9 " 
130.8? 
Wool, ski, 73-534403 
75.3 " 
170„5 " 
126.4? 
Inclo