Medical risks of wilderness hiking

A Tent-Inspired Portable Solar-Driven Water Purification Device for Wilderness Explorers

Wilderness adventure favored by many enthusiasts often endanger lives due to lacking freshwater or drinking contaminated water. Therefore, compared to the inefficient methods of filtration, steaming, and direct solar heating, it is of great meaningfulness to develop a solar-driven water purification device with efficiency, lightweight, portability, and multi-water-quality purification by taking full advantage of solar-driven interfacial evaporation. Here, a tent-inspired portable solar-driven water purification device consisting of Janus-structured bacterial cellulose aerogel (JBCA) solar evaporator and tent-type condensation recovery device is reported. For the JBCA solar evaporator, it is prepared from biomass bacterial cellulose (BC) as raw material and hydroxylated carbon nanotubes (HCNT) as photothermal material, and the Janus property is achieved by the assistance of hydrophobic and hydrophilic chemical cross-linking. It exhibits lightweight, unibody, high photothermal conversion, efficient evaporation, and multi-water-quality purification capability for representative seawater, urine, and bacterial river water. For the tent-type condensation recovery device, it is based on the prototype of tent and uses flexible ultra-transparent polyvinyl chloride (PVC) film as raw material. Thanks to the rational prototype and material selection, it displays outstanding portability and lightweight through the folding/unfolding method. Therefore, the designed tent-inspired portable solar-driven water purification device demonstrates great potential application in wilderness exploration.

Musculoskeletal injuries during trail sports: Sex- and age-specific analyses over 20 years from a national injury database

INTRODUCTION

Musculoskeletal (MSK) injuries in US trail sports are understudied as trail sport popularity grows. This study describes MSK injury patterns among hikers, trail runners, and mountain bikers from 2002 through 2021 and investigates MSK injury trends acquired during mountain sports.

METHODS

The National Electronic Injury Surveillance System (NEISS) was used to identify US emergency department (ED) patients from 2002-2021 (inclusive) who endured MSK injuries during hiking, trail running, or mountain biking. Injury rates and national estimates were calculated across demographics.

RESULTS

9835 injuries were included (48.4% male, 51.6% female). Injuries increased over time, with 1213 from 2002-2005 versus 2417 from 2018-2021. No sex differences existed before 2010, after which female injury rates exceeded those of males. The following findings were statistically significant, with P<0.05: females endured more fractures and strains/sprains; males endured more lacerations; concussions and head injuries were higher among those <18 y; dislocations and strains/sprains were higher for 18 to 65 y; fractures were higher for >65 y; <18 y had high mountain-biking and low running rates; 18 to 65 y had high running rates; and >65 y had low biking and running rates. Although all diagnoses increased in number over time, no significant differences existed in the proportion of any given diagnosis relative to total injuries.

CONCLUSIONS

MSK injuries during trail sports have increased since 2002. Males endured more injuries until 2009, after which females endured more. Significant sex and age differences were found regarding injury diagnosis and body parts. Further studies are needed to confirm these trends and their causes.

Friction Blisters of the Feet: A New Paradigm to Explain Causation

Friction blisters on the feet commonly occur when individuals engage in active pursuits such as running, hiking, and military training. The high prevalence of blisters in active individuals underscores the fact that the pathomechanics of this condition are not fully understood. The traditional blister causation paradigm revolves around heat, moisture, and friction. In reality, foot friction blisters are caused by repetitive shear deformation. The 3 fundamental elements of blister-inducing shear deformation are (1) motion of bone, (2) high friction force, and (3) repetition of the resulting shear events. Rubbing at the skin surface is not a mechanism for friction blister formation. To that end, prevention of the friction blister continues to be an elusive quest for both the patient and the treating clinician. In this article, we aimed to highlight the limitations of the long-held blister-causation paradigm and offer a new explanation.

Influence of blistering lesions on foot functionality in hikers

BACKGROUND

Friction blisters are formed by abrasion from frictional forces on the upper layer of the epidermis and can make physical activity an uncomfortable experience. To our knowledge, no previous studies have considered how these injuries affect the functionality of the foot. For this reason, the main aim of this study was to evaluate foot function in hikers, with or without blisters.

MATERIAL AND METHODS

This case-control study examined 298 hikers who walked the Camino de Santiago long-distance trail (in northern Spain); 207 had one or more blistering foot lesions and 91 had no blisters. Sociodemographic and clinical variables were collected, and the number of blisters and their locations on the foot were recorded. All participants self-completed the Foot Function Index (FFI) questionnaire, in their native language.

RESULTS

Pain and disability were significantly greater among the hikers with blisters (pain p=<0.001; disability p = 0.015). However, there were no significant differences in the limitation of physical activity between those with blisters (case group) and the control group (p = 0.144). Neither was there any correlation between the number of blisters and pain, disability or limitation of activity. However, the location of the lesion did influence foot functionality. Blisters on the metatarsal heads were more limiting and caused greater pain (right foot p = 0.009; left foot p = 0.017), greater disability (right foot p = 0.005; left foot p = 0.005), greater limitation of activity (on right foot p = 0.012) and more loss of foot functionality (right foot p = 0.002; left foot p = 0.007).

CONCLUSION

The hikers with blisters experienced reduced foot functionality in terms of pain and disability. The number of blisters was not related to foot functionality. Blisters located on the metatarsal heads caused the greatest increase in pain, disability and limitation of activity.

Survey of Musculoskeletal Injuries, Prehike Conditioning, and On-Trail Injury Prevention Strategies Self-Reported by Long-Distance Hikers on the Appalachian Trail

INTRODUCTION

Studies show that 40 to 60% of long-distance hikers on the Appalachian Trail experience musculoskeletal (MSK) injuries, but these studies are over a decade old. The increasing popularity of hiking and injury prevention advances warrant re-evaluation of injury patterns. We sought to determine the frequency of self-reported MSK injuries in long-distance hikers on the Appalachian Trail and associations with prehike conditioning and on-trail injury prevention strategies.

METHODS

The Appalachian Trail Conservancy surveys registered hikers annually. Our orthopedic team added 10 questions specific to MSK injury, training, and equipment to the 2018 to 2019 electronic, cross-sectional Appalachian Trail Conservancy survey. Descriptive statistics and frequencies were calculated. Categorical variables were compared using χ² analysis. Correlations were performed for associations between training and gear and MSK injury. Logistic regression assessed the effect of training on MSK injury. Statistical significance was set at P<0.05.

RESULTS

Of 1295 respondents (52% response rate), 61% (n=791) reported MSK complaints; 28% (n=363) reported overuse/chronic MSK injuries, and 18% (n=238) reported acute injuries. MSK complaints resulted in 11% (n=147) stopping their hike. Respondents who did not train (13%, n=168) were significantly more likely to report an MSK injury (odds ratio 2.82; 95% CI 1.92-4.24; P<0.001). Strength training, stretch/yoga, and endurance training were associated with less injury (all P<0.001). Stabilizing footwear and poles/sticks were associated with fewer MSK complaints (all P<0.001).

CONCLUSIONS

Prehike training and hiking gear correlate with fewer injuries. Further research is warranted to elucidate whether promoting injury prevention strategies can reduce MSK injuries among long-distance hikers.

Future-Oriented Coping with Weather Stress among Mountain Hikers: Temperamental Personality Predictors and Profiles

. The aim of the study was to explore temperamental personality traits as predictors of future-oriented coping with weather stress in a group of Polish mountain hikers. The subjects were 209 young mountain hikers (M = 21.20; SD = 3.70) who took three temperament-personality questionnaires, i.e., FCZ-KT Temperament Questionnaire, Sensation Seeking Scale IV and NEO-FFI- Personality Inventory, alongside a recently constructed scale for diagnosing future-oriented coping with weather stress in outdoor context, Preventive and Proactive Coping with Bad Weather Scale in Outdoor Sports. The regression analysis indicated that preventive coping with weather stress in hiking was predicted by activity, emotional reactivity, briskness, sensory sensitivity, experience seeking, agreeableness and conscientiousness. In turn, proactive coping with bad weather in hiking was predicted by endurance, activity, thrill and adventure seeking and extraversion. In turn, the cluster analysis revealed three distinct clusters of hikers characterized by diverse results on the scales of preventive and proactive dealing with adverse weather, namely, prudent hikers (high preventive coping/high proactive coping), reckless hikers (low preventive coping/high proactive coping) and wary hikers (high preventive coping/low proactive coping). The hikers in these clusters differed in terms of temperamental personality traits.

An alternative method for analyzing the slip potential of workers on sloped surfaces

Slips and falls on sloped roof surfaces remain an important safety issue among construction workers. The slip potential has been conventionally analyzed and assessed primarily based on ground reaction forces, which cannot differentiate the specific roles of each of the force factors (e.g., workers' motions-induced dynamic forces and slope-induced static forces) contributing to the slip potential. Their differentiation may enhance the understanding of the slip mechanisms on the sloped roof surfaces and help develop effective walking and working strategies/tactics to minimize the dangerous slips on the elevated roofs. Hence, the objective of this study is to develop a biodynamic method as an additional tool for analyzing the slip potential of a worker walking or working on sloped roof surfaces. A whole-body biodynamic model is proposed and used to develop the alternative method, in which the slip potential is expressed as an analytical function of its major controlling factors including coefficient of friction, slope angle, and biodynamic forces. Some experimental data available in the literature are used to demonstrate the application of the proposed method. The results suggest that the slope may not change the basic trends of the biodynamic forces, but the slope may affect their magnitudes, which can be explained using the system's energy equation also derived from the whole-body biodynamic model. The analytical results suggest that reducing the body acceleration in uphill direction or the deceleration in downhill direction can reduce the slip potential. 'Zigging' and 'zagging' walking on a sloped surface may also reduce the slip potential, as it reduces the effective slope angle. The proposed biodynamic theory can be used to enhance the safety guidelines not only for roofers but also for people walking on ramps, inclined walkways, and mountain terrains.

Grade 4 Distal Femur Stress Fracture in a Long-Distance Hiker on the Appalachian Trail

Although stress injuries are a common occurrence in sports medicine clinics, a distal femur stress fracture is less so. Early detection can result in a favorable prognosis and may prevent the need for surgical intervention. A misdiagnosis resulting in delay of care can result in significant complications. This case report documents a rare distal femur stress fracture in a long-distance hiker. A 35-y-old male presented to an orthopedic clinic in Pennsylvania with left knee pain after completing 1423 km (884 mi) of the Appalachian trail over a 4-mo period. He was attempting a thru-hike, a specialized type of backpacking focused on completing a trail from end-to-end. Thru-hiking of this trail involves backpacking between Georgia and Maine, covering about 3540 km (2200 mi) with approximately 141,580 m (464,500 ft) of gain/loss in elevation. His pain began 2 mo into his hike when he noted medial sided left knee discomfort. Over the following 2 mo he sought treatment at 2 different locations along the trail with etiology undetermined. Upon evaluation in Pennsylvania, history and physical exam were suggestive of a stress fracture. Radiologic studies confirmed a closed nondisplaced nonangulated grade 4 transverse fracture of the shaft of the distal left femur. The patient was instructed to terminate his hike immediately and he was placed on nonweight bearing status. This case illustrates the importance of considering a distal femur stress fracture for the differential diagnosis of persistent knee pain in a long-distance hiker.

Medical Encounters During the United States Army Special Forces Assessment and Selection Course

Introduction

The Special Forces Assessment and Selection (SFAS) is an extremely physically and mentally demanding 19- to 20-day course designed to determine whether Soldiers are qualified to enter the Special Forces Qualification Course. As a first step to understand medical problems during SFAS, this study examined injuries, illnesses, and activities associated with injuries during the course.

Materials and Methods

Medical events during the SFAS course were compiled from Sick Call Trackers (a log of medical encounters maintained by medical personnel in the field) and Chronology of Medical Care (Standard Form 600). Descriptive statistics were calculated for each injury and illness and injuries were compiled by the activities performed when the injuries occurred.

Results

Of the 800 Soldiers who volunteered for the study, 38% (n = 307/800) and 12% (n = 97/800) experienced one or more injuries and/or illnesses, respectively. The most common injuries were blisters and abrasions/lacerations with incidences of 20% (n = 158/800) and 13% (104/800), respectively. The most common illnesses were respiratory infections, other infections, contact dermatitis, and allergies with incidences of 7% (n = 57/800), 2% (n = 14/800), 2% (n = 14/800), and 2% (n = 13/800), respectively. Among all injuries recorded (n = 573), the most common were blisters (46%), abrasions/lacerations (24%), pain (not otherwise specified) (19%), tendonitis (3%), and sprains (3%). Among all illnesses recorded (n = 133), the most common were respiratory infections (56%), allergies (11%), contact dermatitis (11%), and other infections (11%). Most injuries were experienced during land navigation (44%), team events (20%), and foot marching (11%), running (6%), and the obstacle course (5%), but when the estimated time involved for each event was considered, activities with the highest injury rates were the obstacle course (65 injuries/hr), running (27 injuries/hr), the Combat Readiness Assessment (activity involving combat-related tasks) (20 injuries/hr), and foot marching (16 injuries/hr).

Conclusion

The major limitations of this investigation were: 1) the low specificity with regard to many of the diagnoses/complaints; and 2) the fact that the medical problems reported here are only those seen by medical care providers and are likely an underestimate of the total morbidity in the SFAS course. Soldiers often self-treat and some may be reluctant to see medical personnel because of how it might affect their rating in the course. Nonetheless, this investigation alerts medical personnel to the injuries and illnesses to expect, and public health workers and leadership with activities to target for injury prevention measures during SFAS.

Prevalence and risk factors associated with the formation of dermal lesions on the foot during hiking

BACKGROUND

The aim of this study is to assess the prevalence of blisters on the foot during hiking and the factors associated with this condition.

MATERIAL AND METHODS

A cross-sectional observational comparative study was conducted of 315 patients treated at two hostels, located on the Way of Saint James, in northern Spain. The study participants were interviewed and clinically examined to obtain sociodemographic and clinical variables. The variables recorded concerned the type of terrain covered (asphalt or dirt trails), the weight carried (backpack), the footwear used (weight, type, impermeability), the type of socks worn and the hydration of the skin obtained. The inclusion criteria were at least 18 years and to walk at least 20 km in the last five days.

RESULTS

74% (n = 233) of the hikers presented a bullous lesion on the foot after completing several stages of hiking. The most frequent locations were the first or second metatarsal head and the fifth toe. Logistic regression showed that risk factors for the appearance of blistering were the number of kilometres walked on asphalt (p = .001 [95% CI (1.019-1.064)]) and having wet socks at the end of the day (p = . 006 [95% CI (1.286-4.479)]). The protective factors identified were walking on a dirt, grass or gravel surface (p < .001 [95% CI (0.982- 0.995)]) and using customised plantar orthoses (p = .001 [95% CI (0.085) - 0.512)]).

CONCLUSIONS

The type of terrain is a determining factor in the appearance of blisters. Walking on a dirt trail reduces the risk. Using custom made insoles and controlling humidity are other factors that should be considered as preventive measures.

Friction Blister by Climbing Harness: A Case Report

An experienced 24-y-old climber on Mount Everest presented to the Base Camp medical clinic with a friction blister on his right flank. The blister was filled with clear fluid and was located about 3 cm posterior and 3 cm superior to the highest point of the right iliac crest, the site where a climbing harness would support the climber while hanging. A diagnosis of friction blister caused by a climbing harness used while traversing between Camp 2 and Camp 3 of Mount Everest was made. The blister was managed with hydrocolloid dressing, and the patient resumed climbing after 1 wk. The lesion healed with scarring at 2 wk. Friction blisters of the feet are common in climbers wearing ill-fitting shoes, but friction blisters caused by climbing harnesses are unusual and have not been reported in the literature as far as the authors are aware. All existing guidelines for blister management pertain to blisters of the feet, and there are inconsistencies in recommendations made by various authors. This unusual case in an extreme environment provides a good learning opportunity.

Importance of Sock Type in the Development of Foot Lesions on Low-Difficulty, Short Hikes

Background and objectives: Foot lesions can be developed during hiking because of external factors. This makes it important to study the effect of hiking equipment on lesion development. Materials and Methods: Technical and non-technical socks were given to 109 hikers to wear during a short hike. Participants were examined at three stages of the hike to determine the development of dermal, muscle and nail lesions, temperature and perimeter in various areas of each foot. Results: The percentage of hikers without injuries was significantly higher among those wearing technical socks (p-value < 0.001). Differences were also observed in mean foot temperature, which was higher in participants wearing technical socks (p-value < 0.001). Conclusion: The results indicate that even on a low-difficulty, short-term sport activity, it is advisable to wear technical socks to prevent lesion development and keep the foot temperature more stable. Sock type was identified as an external conditioning factor in lesion development.

Importance of Preexisting Physical Factors in the Development of Dermatological and Muscular Lesions During Hiking

Hiking has become very popular due to the physical and mental health benefits it provides. Skin lesions may occur with hiking and various factors contribute to their development. Although some lesions may appear to have little importance, something as simple as chaffing can cause serious ulcers in people with at-risk feet. Few studies have analyzed preexisting physical characteristics in hiking and addressed the development of lesions in hikers. This observational and longitudinal study examines the development of foot lesions during hiking, taking into account the influence of existing skin disorders, nail disorders, and/or toe deformities and other intrinsic factors of participants. The feet of 109 hikers doing a 29.6-km hike were analyzed, considering the intrinsic factors of participants and the possible influence of these factors in the development of foot lesions during the walk. The results show that some preexisting physical factors of participants such as gender, existing systemic disease, preexisting keratosis, dermatosis, nontraumatic and traumatic onychopathies, and toe deformities significantly predispose to the development of skin lesions. These factors also predispose to muscle lesions except for nontraumatic and traumatic onychopathies and toe deformities. Due to the influence of preexisting physical factors, such as preexisting keratosis, dermatosis, and toe deformities, in the development of foot lesions in hikers, it is worthwhile and advisable to check these factors before a hike to reduce the incidence of foot disorders. Ensuring adequate podiatry treatment a few days before the walk and warmup of muscles properly before starting are recommended.

Accidental hypothermia in recreational activities in the mountains: A narrative review

The popularity of recreational activities in the mountains worldwide has led to an increase in the total number of persons exposed to cold and extreme environments through recreation. There is little conclusive evidence about the risk of hypothermia for specific activities or populations, nor is it clear which activities are represented in the literature. This is a non-systematic review of accidental hypothermia in different recreational activities in the mountains, with a specific focus on outdoor or winter activities that potentially involve cold exposure. Cases of hypothermia have been reported in the literature in mountaineering, trekking, hiking, skiing, activities performed in the backcountry, ultra-endurance events, and databases from search and rescue services that include various types of recreation. Of these activities, hypothermia as a primary illness occurs most commonly during mountaineering in the highest elevation areas in the world and during recreation practiced in more northern or remote areas. Hypothermia in skiers, snowboarders, and glacier-based activities is most often associated with accidents occurring off-piste or in the backcountry (crevasse, avalanche). Organizers of outdoor events also have a role in reducing the incidence of hypothermia through medical screening and other preparedness measures. More complete collection and reporting of data on mild hypothermia and temperature measurement would improve our understanding of the incidence of hypothermia in outdoor recreation in future.

Faecal contamination of commuters' hands in main vehicle stations in Dhaka city, Bangladesh

BACKGROUND

Faecal-oral carriage via hands is an important transmission pathway for diarrhoeal pathogens. The level of faecal contamination of commuters' hands in Dhaka, Bangladesh, was examined in this study.

METHODS

A total of 900 hand washing samples, including both left and right hands, were collected during one year to cover three different seasons in Bangladesh: winter, summer and rainy seasons. Standard membrane filtration technique was used to quantify total coliforms (TC), faecal coliforms (FC), faecal streptococci (FS), Escherichia coli (EC) and Clostridium perfringens (CP).

RESULTS

The hands of the commuters were contaminated with TC, FC, FS, CP and EC. The TC, FC, FS, CP and EC counts were 1.95, 1.65, 4.04, 1.54 and1.46 log10 colony forming units (cfu) in the left hand; and 2.13, 1.82, 4.11, 1.52 and 1.61 log10 cfu in the right hand, respectively. There were no statistically significant differences in counts of left and right hands. The highest counts were observed for FS in all seasons.

CONCLUSIONS

This evidence based study may be used to provide interventions to reduce the contamination of commuters' hands through washing with detergent and, thus, help to prevent the spread of infectious diseases.

An Assessment of Diarrhea Among Long-Distance Backpackers in the Sierra Nevada

INTRODUCTION

Diarrhea is a common problem among long-distance backpackers, ranging in overall incidence from 11-56% as reported by previous studies on the Appalachian Trail and Long Trail. Differences in age, sex, and regularity of standard backcountry hygiene recommendations and practices have been shown to significantly affect the incidence of diarrhea. No study to date has investigated these trends among long-distance backpackers on the John Muir Trail (JMT) in the Sierra Nevada mountain range of California.

METHODS

Retrospective analysis of online survey data gathered from long-distance backpackers who attempted a JMT trek in 2014. Data were assessed for the significance of variables that might contribute to the incidence and severity of on-trail diarrhea.

RESULTS

Of 737 valid responders, 16.4% reported experiencing diarrhea (82% with minimal/mild severity; 18% with significant severity). Regular hand sanitizer use was significantly correlated with more severe diarrhea (P < .05), but had no effect on incidence. Regular hand sanitizer users followed all other recommended hygiene practices as frequently as or better than those not using hand sanitizer regularly. Of all backpackers, 88% filtered or treated their drinking water regularly, with 18% of those reporting diarrhea of any severity.

CONCLUSIONS

JMT backpackers have a comparatively lower incidence of diarrhea than backpackers on other major long-distance backpacking routes in the United States. Most JMT backpackers follow standard backcountry hygiene recommendations, including regular filtration or treatment of drinking water. No statistical significance was found between the incidence of diarrhea and compliance with standard hygiene recommendations. Regular hand sanitizer use was significantly correlated with more severe diarrhea but was not associated with incidence. There was no significant difference in compliance with standard backcountry hygiene practices between regular and infrequent hand sanitizer users.

A review of piroplasmid infections in wild carnivores worldwide: importance for domestic animal health and wildlife conservation

Piroplasmids are tick-borne protozoan parasites that infect blood cells (erythrocytes, lymphocytes or other leukocytes) or endothelial cells of numerous wild and domestic vertebrates worldwide. They cause severe disease in livestock, dogs, cats, wild mammals and, occasionally, in humans. Piroplasmid infections are prevalent in wild carnivores worldwide although there is limited information about their clinical and epidemiological importance. There are currently nine recognized species of Babesia, two of Theileria, two of Cytauxzoon and one of Rangelia infecting captive and wild carnivores, including members of Canidae, Felidae, Mustelidae, Procyonidae, Ursidae, Viverridae, Hyaenidae and Herpestidae in the Americas, Eurasia and Africa. However, the number of piroplasmid species is likely higher than currently accepted due to the reported existence of DNA sequences that may correspond to new species and the lack of studies on many host species and biogeographical areas. Indeed, many species have been recognized in the last few years with the advancement of molecular analyses. Disease and mortality have been documented in some wild carnivores, whereas other species appear to act as natural, subclinical reservoirs. Various factors (e.g. unnatural hosts, stress due to captivity, habitat degradation, climate fluctuation or immunosuppression) have been associated with disease susceptibility to piroplasmid infections in some species in captivity. We aimed to review the current knowledge on the epidemiology of piroplasmid infections in wild carnivores and associated tick vectors. Emphasis is given to the role of wild carnivores as reservoirs of clinical piroplasmosis for domestic dogs and cats, and to the importance of piroplasmids as disease agents for endangered carnivores.

Paper Tape Prevents Foot Blisters: A Randomized Prevention Trial Assessing Paper Tape in Endurance Distances II (Pre-TAPED II)

OBJECTIVE

To determine whether paper tape prevents foot blisters in multistage ultramarathon runners.

DESIGN

Multisite prospective randomized trial.

SETTING

The 2014 250-km (155-mile) 6-stage RacingThePlanet ultramarathons in Jordan, Gobi, Madagascar, and Atacama Deserts.

PARTICIPANTS

One hundred twenty-eight participants were enrolled: 19 (15%) from the Jordan, 35 (27%) from Gobi, 21 (16%) from Madagascar, and 53 (41%) from the Atacama Desert. The mean age was 39.3 years (22-63) and body mass index was 24.2 kg/m (17.4-35.1), with 31 (22.5%) females.

INTERVENTIONS

Paper tape was applied to a randomly selected foot before the race, either to participants' blister-prone areas or randomly selected location if there was no blister history, with untaped areas of the same foot used as the control.

MAIN OUTCOME MEASURES

Development of a blister anywhere on the study foot.

RESULTS

One hundred six (83%) participants developed 117 blisters, with treatment success in 98 (77%) runners. Paper tape reduced blisters by 40% (P < 0.01, 95% confidence interval, 28-52) with a number needed to treat of 1.31. Most of the study participants had 1 blister (78%), with most common locations on the toes (n = 58, 50%) and heel (n = 27, 23%), with 94 (80%) blisters occurring by the end of stage 2. Treatment success was associated with earlier stages [odds ratio (OR), 74.9, P < 0.01] and time spent running (OR, 0.66, P = 0.01).

CONCLUSION

Paper tape was found to prevent both the incidence and frequency of foot blisters in runners.

An Assessment of Coliform Bacteria in Water Sources Near Appalachian Trail Shelters Within the Great Smoky Mountains National Park

OBJECTIVE

Hikers and campers are exposed to risks while in the wilderness. One of these risks is the possibility of contracting an illness, including infectious diarrhea. This project tested for coliform bacteria in water samples taken near popular Appalachian Trail shelters.

METHODS

Water was collected from access points within the Great Smoky Mountains National Park. Samples were collected in sterile bottles and inoculated on a commercially available coliform detection kit for quantitative determination of total coliform and Escherichia coli counts.

RESULTS

Water samples were taken during summer and fall seasons. During summer, 7 of 10 samples were positive for coliform bacteria and 6 of those 7 for E coli. The most probable number (MPN) of colony-forming units (CFU) for coliform bacteria ranged from 0 to 489 CFU/100 mL, with the MPN for E coli varying from 0 to 123 CFU/100 mL. These data differed from the fall collection, revealing 3 of 7 samples positive for coliform bacteria and 1 of those 3 for E coli. The MPN of CFU for coliform bacteria in fall samples varied from 0 to 119 CFU/100 mL and 0 to 5 to CFU/100 mL for E coli.

CONCLUSIONS

Environmental Protection Agency drinking water standards set the standard of 0 CFU/100 mL to be considered safe. This analysis of water samples along the Appalachian Trail emphasizes that the majority of water access points require treatment during the summer season. Coliform burden was not as high through the fall months. These data suggest one infectious disease risk for wilderness travelers.

Sensory Enhancing Insoles Modify Gait during Inclined Treadmill Walking with Load

INTRODUCTION

Inclined walking while carrying a loaded backpack induces fatigue, which may destabilize gait and lead to injury. Stochastic resonance (SR) technology has been used to stabilize spatiotemporal gait characteristics of elderly individuals but has not been tested on healthy recreational athletes. Herein, we determined if sustained vigorous walking on an inclined surface while carrying a load destabilizes gait and if SR has a further effect.

METHODS

Participants were fitted with a backpack weighing 30% of their body weight and asked to walk at a constant self-selected pace while their feet were tracked using an optical motion capture system. Their shoes were fitted with SR insoles that were set at 90% of the participant's sensory threshold. The treadmill incline was increased every 5 min until volitional exhaustion after which the treadmill was returned to a level grade. SR stimulation was turned ON and OFF in a pairwise random fashion throughout the protocol. Spatiotemporal gait characteristics were calculated when SR was ON and OFF for the BASELINE period, the MAX perceived exertion period, and the POST period.

RESULTS

Vigorous activity increases variability in the rhythmic stepping (stride time and stride length) and balance control (double support time and stride width) mechanisms of gait. Overall, SR increased stride width variability by 9% before, during, and after a fatiguing exercise.

CONCLUSION

The increased stride time and stride length variability may compromise the stability of gait during and after vigorous walking. However, participants may compensate by increasing double support time and stride width variability to maintain their stability under these adverse conditions. Furthermore, applying SR resulted in an additional increase of stride width variability and may potentially improve balance before, during, and after adverse walking conditions.

Footwear traction and three-dimensional kinematics of level, downhill, uphill and cross-slope walking

Outdoor activities are a popular form of recreation, with hiking being the most popular outdoor activity as well as being the most prevalent in terms of injury. Over the duration of a hike, trekkers will encounter many different sloped terrains. Not much is known about the required traction or foot-floor kinematics during locomotion on these sloped surfaces, therefore, the purpose was to determine the three-dimensional foot-floor kinematics and required traction during level, downhill, uphill and cross-slope walking. Ten participants performed level, uphill, downhill and cross-slope walking along a 19° inclined walkway. Ground reaction force data as well as 3D positions of retro reflective markers attached to the shoe were recorded using a Motion Analysis System. Peak traction coefficients and foot-floor kinematics during sloped walking were compared to level walking. When walking along different sloped surfaces, the required traction coefficients at touchdown were not different from level walking, therefore, the increased likelihood of heel slipping during hiking is potentially due to the presence of loose material (rocks, dirt) on hiking slopes, rather than the overall lack of traction. Differences in required traction were seen at takeoff, with uphill and cross-sloped walking requiring a greater amount of traction compared to level walking. Changes in sagittal plane, frontal plane and transverse plane foot-floor angles were seen while walking on the sloped surfaces. Rapid foot-floor eversion was observed during cross-slope walking which could place the hiker at risk of injury with a misstep or if there was a slight slip.

Appalachian Trail hikers' ability to recognize Lyme disease by visual stimulus photographs

BACKGROUND

Lyme disease is the most common vector-borne infectious disease in North America. With nearly 2,500 Appalachian Trail (AT) hikers entering the endemic area for as long as 6 months, exposure to the disease is likely. The characteristic exanthem of erythema migrans (EM) should be a trigger for seeking medical treatment, and its recognition in this relatively isolated environment is important.

OBJECTIVE

The purpose of this study was to determine the ability of AT hikers to identify EM, the exanthem of Lyme disease.

METHODS

Hikers were administered a photographic stimulus in this Internal Review Board-approved pilot study. Historical hiking data, basic demographics, and self-reported treatment and diagnosis were collected.

RESULTS

In all, 379 responses were collected by 4 researchers at 3 geographically separate locations at or proximate to the AT from June 2011 to May 2012. Fifty-four percent of respondents (206 of 379) were able to recognize the photographs of EM/Lyme disease; 46% could not. Of those who did recognize EM, 23 (6%) had seen it either on themselves or on another hiker while on the AT. A total of 37 hikers stated that they had been diagnosed with Lyme disease while hiking, and of these, 89% were treated with antibiotics. Thirteen of these 37 hikers (35%) diagnosed with Lyme disease had visualized an embedded tick. Nine percent of all respondents reported they had been diagnosed with Lyme disease by a healthcare practitioner, whether from EM, symptomatology, or by titer.

CONCLUSIONS

This study suggests that hikers are poorly able to recognize the characteristic exanthem of Lyme disease but have a high exposure risk.

High fecal hand contamination among wilderness hikers

Information about hand hygiene and fecal hand contamination among the general public is limited. Hands are an important vector in transmission of various pathogenic bacteria. We found high (31%) prevalence of fecal hand contamination among healthy adults engaged in hiking.

Helicopter rescue involving the winching of a physician

INTRODUCTION

We sought to study the operational and medical aspects of helicopter rescue missions involving the use of a winch.

SETTING

A single helicopter-based medical service of a pre-alpine region of Switzerland.

METHODS

We prospectively studied consecutive primary rescue interventions involving winching of a physician, from October 1, 1998 to October 1, 2002. Demographic, medical and operational aspects as well as outcome at 48 hours were analyzed.

RESULTS

We included 133 patients. Most (74%) were male, with traumatic injuries (77%). The median scene time of the nine severely injured patients (Injury Severity Scale [ISS] > 15) was significantly longer compared with the other patients (54 vs 37 minutes; P < .05). The main medical procedures performed were orotracheal intubation (n = 5), fracture reductions (n = 5), major analgesia with sedation (n = 4), and intravenous fluid administration of more than 1,500 mL (n = 4). Fourteen (10%) patients suffering from minor injuries were triaged by the physician and not airlifted to the hospital. All 133 patients were alive at 48 hours. Sixty-nine (52%) were still hospitalized. No secondary interhospital transfer was required.

CONCLUSION

Our study provides a better knowledge of injury profile, medical aspects, and outcomes of patients rescued necessitating a winching procedure.

Injuries to individuals participating in mountain and wilderness sports: a review

OBJECTIVE

The objective of this review is to summarize evidence on injuries occurring in individuals participating in mountain and wilderness sports.

DATA SOURCES

Scopus, ISI Web of Knowledge, SPORTDiscus, Ovid Safety and Health, Index to Theses, COPAC, and sportscotland e-library. The search terms were (mountain* or wilderness or adventure or climb* or (hill walk*)) and (accident* or injur* or rescue*) and (epidemiolog* or statistic* or pattern* or survey*). The search period was from 1987 to 2010.

STUDY SELECTION

A total of 2034 articles were identified. The full text of 137 articles was retrieved. Fifty articles met inclusion criteria-mountain and wilderness; nonmotorized, leisure time, outdoor activities; and nonfatal injury. Skiing and snowboarding articles were excluded.

DATA EXTRACTION

Study design was classified using the "STOX" hierarchy of evidence. Study quality was rated independently by 2 reviewers.

DATA SYNTHESIS

All studies were observational. Twenty-one (42%) were longitudinal, 20 (40%) were cross-sectional surveys, and 9 were cohort studies. A majority of casualties were aged 20 to 39 years. There was a clear male majority, 70% to 89% in most studies. The percentage of casualties who sustained severe injuries ranged from 5% to 10%--less than 10% were admitted to hospital. Casualties sustained an average of 1.2 to 2.8 injuries (most >1.6), which mainly affected the soft tissues; between 2% and 38% were fractures. Up to 90% of injuries were to the extremities.

CONCLUSIONS

The majority of mountain and wilderness sports injuries are minor to moderate. However, some casualties have life-threatening medical problems, which may have long-term implications for return to sport and general well-being.

Preventing injuries and illnesses in the wilderness

Wilderness trips have become increasingly popular, especially in the adolescent population. The wilderness can be a source of rejuvenation while being mentally and physically challenging; however, it is also fraught with the potential for injury, illness, and even death. Epidemiologic studies of injuries and illnesses from hikers are not extensive, but there are sufficient data to identify the most common risk factors to offer some strategies for prevention. Many youth will have a medical visit or preparticipation physical assessment before an organized wilderness experience. This article highlights commonly seen wilderness injuries and illnesses and provides guidance for proper planning and problem solving.

Search and rescue trends associated with recreational travel in US national parks

BACKGROUND

National parks are popular travel destinations worldwide. Unfortunately, negative health experiences can and do occur during travel in national parks. This study investigated search and rescue (SAR) trends associated with recreational travel in US National Park Service (NPS) units.

METHODS

A retrospective study was conducted of the Annual US National Park Service Search and Rescue Report for the years 2003 to 2006.

RESULTS

From 2003 to 2006, there were 12,337 SAR operations involving 15,537 visitors. The total operational costs were US$16,552,053. The operations ended with 522 fatalities, 4,860 ill or injured visitors, and 2,855 saves. Almost half (40%) of the operations occurred on Saturday and Sunday, and visitors aged 20 to 29 years were involved in 23% of the incidents. Males accounted for 66.3% of the visitors requiring SAR assistance. Day hiking, motorized boating, swimming, overnight hiking, and nonmotorized boating were the participant activities resulting in the most SAR operations. The vast majority of visitors requiring SAR assistance were located within a 24-hour period, and the most common rescue environments were mountain areas between 1,524 and 4,572 m, lakes, rivers, oceans, and coastal areas. An error in judgment, fatigue and physical conditions, and insufficient equipment, clothing, and experience were the most common contributing factors.

CONCLUSIONS

SAR incidents can be expensive and end with severe health consequences. NPS management should develop education and preventive efforts focused on hikers, boaters, and swimmers who are males and aged 20 to 29 years, addressing issues of adequate judgment, preparation, and experience.

Injuries Sustained at Yellowstone National Park Requiring Emergency Medical System Activation

OBJECTIVE

Outdoor-related activity has been on the rise in recent years, and hiking and backpacking are among those activities with the largest growth in participation. As the number of participants with varying experience increases, it is expected that there will be an increase in injuries related to these activities. Little empirical data exist related to outdoor injury types and rates. Our objectives were to determine incidence and frequency of injuries related to outdoor activity and requiring emergency medical system (EMS) activation at a national park.

METHODS

This retrospective study examines injuries within Yellowstone National Park. Subjects were selected from a database containing all EMS calls within Yellowstone National Park from calendar year 2003 through 2004. Data collected included age, gender, type of injury, location, activity at the time of injury, and EMS response.

RESULTS

There were 306 injuries reviewed. The mean age of patients was 40.9 years (SD: 23.0), and the group comprised 49.0% males. Emergency medical system transport was not required in 59.2% of injuries, and of those transported, 58.4% of patients required basic life support only. Of all injuries, 77.4% involved soft tissue, including lacerations. Hiking and walking accounted for 38.0% of all injuries, and 56.0% of those injuries involved the lower extremity. Only 8.8% of the injuries involved fractures and/or dislocations.

CONCLUSIONS

In this study of EMS responses at a national park, the majority of injuries sustained were minor in nature. More than one third of injuries occurred while patients were hiking or walking, and most of those injuries involved the lower extremity. These results will help optimize resource planning in the national park setting.

Search and Rescue in Yosemite National Park: A 10-Year Review

OBJECTIVE

To describe the general characteristics and epidemiology of search and rescue (SAR) in Yosemite National Park (YNP) and identify possible areas for intervention directed at reduction in use of these services.

METHODS

Yosemite Search and Rescue (YOSAR) personnel record every search and rescue mission on a Search and Rescue Incident Report. The information contained in these reports was used to perform a retrospective review of all SAR missions within YNP during the 10-year study period between January 1990 and December 1999.

RESULTS

YOSAR performed 1912 SAR missions, assisting 2327 individuals and recording 2077 injuries and illnesses. Popular trails in and around Yosemite Valley collectively accounted for 25% of all individuals needing SAR services. Lower extremity injuries and dehydration/hypovolemia/hunger were commonly identified reasons to need SAR services. The duration of SAR missions averaged 5 hours, used 12 SAR personnel, and cost $4400. Helicopter was the primary mode of transport in 28% of SAR incidents. There were 112 fatalities, yielding a SAR case fatality rate of 4.8%. The majority of fatalities occurred while hiking/snowshoeing, with falling the most common mechanism of lethal injury.

CONCLUSIONS

Day-hikers in and around Yosemite Valley use a large portion of SAR services, with lower extremity injuries and dehydration/hypovolemia/hunger the most common reasons. It seems reasonable to direct future intervention to prevention of these commonly identified problems in this particular population of Park visitors.

Alpine climbing: injuries and illness

Alpine climbing is a sport whose participants are at risk for a variety of injuries and illnesses. Climbers are venturing into the mountains and attempting routes with ever-increasing difficulty, and it is important to understand the injury and illness concerns of alpine climbers better. Alpine climbers are prone to injuries common to traditional mountaineers and more specialized sport rock climbers. Falls while climbing represent one of the more common causes of serious injury, although acute and chronic musculoskeletal injuries of the hands and extremities are also frequent afflictions. Alpine climbers are at risk for injuries and illness because of the mountain environment where they participate in their sport. Proper preparation for the cold is imperative to prevent frostbite and hypothermia. Worsening symptoms of headache or respiratory symptoms should always alert the alpine climber to possible altitude illness. Understanding the injuries common to the sport can allow providers to deliver the best medical care.

Wilderness event medicine: planning for mass gatherings in remote areas

BACKGROUND

An increasing number of large recreational events are taking place in remote environments where medical care is far away. Such events include adventure races and large outdoor trips. Wilderness event medicine (WEM) has been previously defined as the healthcare response at any discrete event with more than 200 persons located more than 1h from hospital treatment. However, there is little literature describing the steps for providing medical care at such events.

METHODS

This article provides a framework for planning and executing WEM. It reviews the published data on wilderness injury and illness rates and describes the nature of injuries as they relate to specific activities. The article then discusses the three stages of WEM: pre-event planning, medical treatment at the event, and post-event tasks.

RESULTS

Wilderness events include myriad activities, including orienteering, mountain biking, mountaineering, and whitewater paddling. The injury and illness rates are in the range of 1-10 per 1000 person-days of exposure, with rates one order of magnitude greater for events which last many days, include extremes of environment (heat, altitude), or are competitive in nature. Professional adventure racers may present for medical evaluation at rates as high as 1000 encounters per 1000 racer-days. Injuries depend largely on activity. Illnesses are mostly gastrointestinal, 'flu-like' malaise, or related to the event environment, such as humidity or altitude. Providing medical care requires the proper staff, equipment, and contingency plans. The remoteness of these events mandates different protocols than would be used at an urban mass gathering.

CONCLUSIONS

WEM will likely continue to grow and evolve as a specialty. Additional reports from wilderness events, perhaps facilitated through a web-based incident reporting system, will allow medical providers to improve the quality of care given at remote events. Research into wilderness activity physiology will also be useful in understanding the prevention and treatment of injuries and illnesses encountered.

Influence of hygiene on gastrointestinal illness among wilderness backpackers

BACKGROUND

Gastrointestinal illness is a common risk for wilderness travelers, even among those who consistently disinfect their water, yet the importance of hygiene has not been characterized.

METHODS

In a prospective surveillance study, 334 Appalachian Trail backpackers who hiked for at least 7 days in 1997 were interviewed. Upon completion of their hike, a written questionnaire was sent, addressing illnesses, water disinfection methods, and hygiene. Hygiene inquiries focused on the frequency of behaviors concerning handwashing and cleaning cookware.

RESULTS

Two hundred and eighty backpackers compiled 38,940 wilderness exposure days, with 56% (n=56) experiencing diarrhea. Diarrhea correlated with the frequency of drinking untreated surface water (relative risk (RR) 2.4, 95% confidence interval (CI) 1.0-4.7%, p5.03). Of those who consistently treated water, 45% suffered from diarrhea, whereas 69% of those who inconsistently treated water experienced diarrhea (RR 0.65, 95% CI 0.53-0.81%, p5.001). Hikers practicing "good hygiene", defined as handwashing post-defecation and cleaning cookware routinely, were less likely to ever experience diarrhea (RR 0.47, 95% CI 0.22-0.99, p5.04). Routine handwashing with soap and water after both urination and defecation reduced the risk of diarrhea (RR 0.11, 95% CI 0.04-0.31%, p,.001). In a case-control analysis of those experiencing diarrhea, decreased diarrhea was associated with routine consumption of multivitamins (RR 0.50, 95% CI 0.37-0.66%, p,.001), routine cleaning of utensils with warm, soapy water (RR 0.38, 95% CI 0.20-0.74%, p,.01), and post-defecation handwashing with soap and water (RR 0.61, 95% CI 0.39-0.93%, p5.006).

CONCLUSIONS

Lack of hygiene, specifically handwashing and cleaning of cookware, should be recognized as a significant contributor to wilderness gastrointestinal illness. Hikers should routinely disinfect water and avoid untreated surface water.

Travel health advice for backpackers

There has been an increasing trend for people to travel internationally, further afield, but fewer people are now going on programmed package tours. One of these groups of travelers comprises backpackers, who are distinct from endurance hikers or trekkers and longer-term and more remote expeditioners. Backpackers comprise individuals who travel alone or in a small group on a limited budget, and usually stay in hostels (hostelers), campsites, or similar low-cost accommodation, and carry their belongings in personal load-carrying equipment, most notably backpacks. Individual travel through backpacking, especially hosteling, appears to have become more popular for three probable reasons: travelers are seeking more cost-effective means of traveling and accommodation; they are looking to travel to regions where there is less likelihood of meeting fellow travelers; and they are looking for travel with more risk attached.