Risk factors for foot blisters during road marching: tobacco use, ethnicity, foot type, previous illness, and other factors.

Three hundred thirty-nine freshmen participating in cadet basic training at the U.S. Military Academy completed a questionnaire that asked them about their previous military experience, gender, ethnicity, injuries and illness experienced in the last 12 months, foot type, cigarette smoking habits, smokeless tobacco use, alcohol consumption, and sleep habits. They then performed a 21-km road march in about 6.5 hours. Their feet were examined for blisters before and after the march. Univariate analysis showed that risk factors for foot blisters included ethnicity (blacks at lower risk than others), a sickness in the last 12 months, no previous active duty military experience, use of smokeless tobacco, and flat feet (pes planus). Logistic regression indicated that all of these were independent blister risk factors with the exception of no previous active duty military experience.