Backpacking-induced paresthesias

Objective.-To evaluate the presence of numbness and paresthesias among long-distance backpackers on the Appalachian Trail. Methods.-Backpackers who hiked a minimum of 7 days were interviewed while hiking. Following their hike, a written questionnaire was mailed to the participants that explored the incidence of injuries and illnesses among hikers. Paresthesias were defined as either numbness or "phantom, burning, or shooting pains." A case-control analysis of risk factors for paresthesias was performed. Results.-Paresthesias were reported by 34% (96 of 280) of the backpackers completing the study. They included ulnar paresthesias (n = 4), meralgia paresthetica (n = 10), tarsal tunnel syndrome (n = 6), digitalgia paresthetica (n = 21), and nonspecific paresthesias (n = 61). The most common symptom was numbness: 81% (78 of 96). Significant risk factors included a distance of >2000 miles (relative risk [RR] = 1.3; 95% CI, 1.1-1.6; P = .01) and the duration of hiking (RR = 2.0; 95% CI, 1.2-3.2; P = .004) for the longest quartile. Nonsignificant factors included backpack weight, initial body weight, percentage of weight loss, running shoe usage, and multivitamin usage. Ninety-eight percent of the paresthesias (94 of 96) had resolved by the time of follow-up (median = 30 days). Conclusions.-Paresthesias were a surprisingly common complaint among long-distance backpackers. Although they were distressing during backpacking, these neuropathies were self-limited and resolved after completion of hiking.