This study examined the influence of three types of boot-sock systems
on incidence and severity of foot blisters, Participants were 357 men
undergoing U.S. Marine recruit training at Parris Island, South Caroli
na, Each participant was assigned to one of three treatment groups, Th
e first group wore the standard military boot sock consisting of a woo
l-cotton-nylon-Spandex combination, The second group wore the standard
military boot sock with a thin inner or liner sock consisting of poly
ester, The third group wore a very thick, dense, prototype outer sock
consisting of a wool-polypropylene combination over the same liner soc
k as the second group, Foot blister incidence was lower among particip
ants who wore the the prototype boot sock and liner than among those w
earing the standard military sock (40 vs, 69%, p < 0.001) or among sub
jects wearing the standard military sock with liner (40 vs, 77%, p < 0
,001). Foot blisters and cellulitis severe enough to require medical a
ttention occurred with greater frequency in the standard military sock
group compared to both the prototype boot-sock group (24 vs, 11%, p =
0.02) and the standard military sock with liner group (24 vs. 9%, p <
0,01); there was no difference between the latter two groups, Blister
reduction was most apparent in the early weeks of recruit training. T
he standard military sock with a polyester liner reduced the incidence
of severe blisters, but the dense sock with the polyester liner reduc
ed the overall incidence of blisters as well as the incidence of sever
e blisters.