バックパックの重量と怪我は無関係
There are a few studies concerning pack weight and injury.
Hamonko et al (2011) may be the best research. They conducted the 1
year prospective randomized comparative research at the Rocky
mountaineering school. They examined the relation of real injury to
physical factors. They found that the pack weight ( from 9.1 kg to
38.6 kg ) , age, gender, et al. had not related to the injury. ( UL
course was also included. )
The questionnaire method is inferior to the above method. There are
two studies.
Lobb(2004) conducted questionnaire study to 2,403 trampers in New
Zealand. They found that the packweight, age, and gender, et al had
not related to injury. Their average pack weight was 20 kg.
Anderson, et al.( 2009) carried out questionnaire methdod to 128 AT
and PCT hikers. They found pack weight, footwear had not related to
injury.
Reference
Hamonko, M.T., McIntosh, S.E., Schimelpfenig, T., \& Leemon, D. \ \
2011 \ \ Injuries related to hiking with a pack during National
Outdoor Leadership School courses: a risk factor analysis. {\it
Wilderness Environmental Medicine}, 22, 2-6.
Lobb, B. \ \ 2004 \ \ Load carriage for fun: a survey of New Zealand
trampers, their activities and injuries. {\it Applied Ergonomics}, 35,
541-547.}
Anderson, L.S. Jr, Rebholz, C.M., White, L.F., Mitchell, P., Curcio,
E.P. 3rd, Feldman, J.A., \& Kahn, J.H. \ \ 2009 \ \ The impact of
footwear and packweight on injury and illness among long-distance
hikers. {\it Wilderness Environtal Medicine}, 20, 250-256.
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Experience doesn't always mean good judgment nor outdoor skills.
経験豊富でも判断や技能が優れているとは限らない。
経験を積んでも怪我は減らない。素人でもベテランでも怪我の確率は同じ。経験を積めば少しは賢くなるかもしれないが、怪我を減らせるほどは賢くならないようだ。あるいは、ベテランは、難しいことに挑戦するからかもしれない。そうすると、我々は誰でも同じ危険確率を求めて行動することになる。ちょっと心理学的で面白い。
Concerning the "judgement", I found a survey of New Zealand trampers(
Brenda Lobb; Ergonomics 35 (2004) 541?547) . Injuries were reported by
74\%, with sprains
being the most common injury type and knees, ankles and feet the most
frequent location of injury.
They found injury do no correlate to age, sex, body fitness, and
tramping experience. So, the probability of injury might be equal to
all person. Is this means experience do not prevent injury ?
Experience may improve judgment, but judgment do not prevent injury.
The experienced trampers may like to hike more difficult places.
Hiking is not a adventure. Safety is the most important. Safety may be
obtained by eliminating unnecessary items as UL or by adding necessary
items. The judgement of necessity depends on hikers skills and
physical conditions.
Appl Ergon. 2004 Nov;35(6):541-7.
Psychology Department, Tamaki Campus, The University of Auckland, Private Bag 92019, New Zealand. b.lobb@auckland.ac.nz
Much of the published research investigating the physiological, biomechanical and psychological impact of load carriage by backpack has studied young, fit males carrying loads for an hour or less. The resultant body of knowledge may not be appropriate to the increasing numbers of middle-aged and older men and women who are taking up or returning to tramping as a recreational activity. In this study, members of 11 tramping clubs throughout New Zealand were surveyed to discover their personal characteristics, characteristics of tramping trips undertaken and injuries sustained. Significant numbers of men and women over 30, 40 and 50 years of age and with generally sedentary lifestyles reported occasional tramping during which they carried backpacks weighing up to 29% of their body weight for more than five hours over 11-15 km/day. Injuries were reported by 74%, with sprains being the most common injury type and knees, ankles and feet the most frequent location of injury. These findings may have implications for route planning and the design of interventions to reduce injuries, health care, training, tracks, equipment and footwear, and demonstrate the need for further research to investigate the risks and requirements of recreational trampers.
Table 7. Injuries received while tramping
Table 8. Percentage of injuries by body part (n=362)
There was no statistically significant difference in number of injuries reported between men and women, or between age groups, except that those aged 41–50 years reported more injuries than those aged over 50 years (one-way ANOVA using Bonferroni post hoc analyses, p<0.05). There was no correlation between reported level of fitness or health and number of injuries, between injuries reported and tramping experience, nor was there any correlation between injuries reported and duration of tramping trip.
(訳)
ケガの頻度について、41～50歳が50歳以上よりも多いという点を除外すると、男性と女性の間には統計的有意差がなかった。また、フィットネスの程度や健康度とケガの頻度、トランピングの経験とケガの頻度、さらに、トランピングの期間とケガの頻度との間には相関がなかった。
2008年から2009年にRocky MountainのOutdoor Schoolでの前向き研究(縦断的研究)、したがって、妥当性は高いはず。最終的に1201名のバックパックの重さ、身長、体重、年齢、性別などを分析したが、どの要因も怪我などの事故を予測できなかった。light and fast backpacking courseもあったが、怪我の率には無関係だった。
Wilderness Environ Med. 2011 Mar;22(1):2-6.
Hamonko MT, McIntosh SE, Schimelpfenig T, Leemon D.
Department of Surgery, Division of Emergency Medicine, University of Utah, Salt Lake City, UT, USA. matt.hamonko@gmail.com
To determine if packweight, anthropometry, and individual characteristics are related to acute musculoskeletal and soft tissue injuries while wearing backpacks on wilderness expeditions.
This was a review of prospectively gathered data on participants and instructors enrolled in National Outdoor Leadership School Rocky Mountain hiking courses between March 2008 and October 2009. Packweight, height, body weight, age, and gender were collected. Individuals that suffered acute musculoskeletal and soft tissue injuries while hiking with a backpack were recorded and compared to individuals that did not suffer injuries. Logistic regression was used to determine which variables were significantly correlated with injuries. Odds ratios with associated confidence intervals and p-values are reported.
One thousand two hundred and one individuals were included in the final analysis. Twenty-six individuals of this population suffered reportable musculoskeletal and soft tissue injuries while hiking with a pack. None of the factors examined (packweight, height, body weight, age, gender, or packweight to body weight ratio) were significant in predicting acute injury.
Based on our results, an individual's packweight, anthropometry, and individual characteristics neither increase nor decrease their risk of experiencing a musculoskeletal or soft tissue injury while hiking with a backpack. Other factors, including fitness, pretrip training, and footwear, should be examined to determine appropriate strategies to reduce significant musculoskeletal and soft tissue injuries on wilderness expeditions.
これは少し前の研究
怪我はブーツを履いた人に多いが、原因は荷物の重さにあるという研究。荷物の重さを統制すると、靴の種類と怪我の関係は消失する。これなんかも、因果関係の誤解からだろう。シューズの方が怪我が少ないと勘違いして、重い荷物を背負う人がシューズに変えると大けがをする。馬鹿みたい。人間は賢くないので、用心、用心。俺も靴の軽量化では失敗の連続。
OBJECTIVES:
METHODS:
RESULTS:
CONCLUSIONS:
Wilderness Environ Med. 2009 Fall;20(3):250-6.
Anderson LS Jr, Rebholz CM, White LF, Mitchell P, Curcio EP 3rd, Feldman JA, Kahn JH.
Boston Medical Center, Department of Emergency Medicine, Boston, Massachusetts, USA. andersonstew@gmail.com
Comment in:
OBJECTIVE: To determine the prevalence and predictors of injury and illness among long-distance hikers.
METHODS: This was a cross-sectional study of long-distance hikers (> 500 miles [805 km]) along the Appalachian Trail and Pacific Crest Trails between August and October of 2006. An 8-page survey instrument was made available to hikers at a designated station near the northern terminus of the respective trails. The survey questions were yes/no or multiple choice. Independent variables included packweight, footwear, and type and frequency of water purification. chi(2) tests to compare categorical data and the Cochran-Armitage test for trend were used (P < .05 significant). We used logistic regression to compare the variables concurrently, and significance was determined using likelihood ratio tests. Profile likelihood confidence intervals for the odds ratios are reported.
RESULTS: Of the 128 hikers completing surveys that met inclusion criteria, the mean age was 33 years (range = 18-65 years), 94% walked >1500 miles (2400 km), and 70% were male. Using univariate analysis, trends were noted in the proportion of hikers reporting paresthesias and increasing packweight (35% with 10-20 pound [4.5-9 kg] packs, 50% with 21-30 pound [9.5-13.5 kg] packs, and 69% with >31 pound [14 kg] packs [P < .002]), as well as in the proportion of hikers reporting paresthesias and increasing footwear rigidity (29% sandals, 36% running shoes, 42% hiking shoes, and 68% hiking boots [P < .001]). In multivariate analysis compared to sandals, the odds ratio of suffering from paresthesias with running shoes was 1.57 (95% CI 0.3, 12.2), hiking shoes 1.73 (95% CI 0.3, 13.9), and hiking boots 3.9 (95% CI 0.7, 32.1) (P = .16). Compared to 10 to 20 pound (4.5-9 kg) packs, the odds ratios of suffering from paresthesias with 21 to 30 pound (9.5-13.5 kg) packs was 1.5 (95% CI 0.6, 3.9), and for > 31 pounds (14 kg) was 2.2 (CI 0.7, 7.1) (P = .03). Adjusting for footwear and pack weight, only pack weight was significantly associated with paresthesias. Packweight and footwear were not significantly associated with other musculoskeletal injuries, such as joint sprains or chronic pain, and muscle injuries.
CONCLUSIONS: There is an association between packweight and the prevalence of paresthesias among long-distance hikers. The association between type of footwear and the prevalence of paresthesias is significant when analyzed independently, but loses its significance when the variables are examined together. This suggests that there is confounding between footwear and packweight.