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.

-----------------------------------------------------------------------------------------------------------------------------------

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.

Load carriage for fun: a survey of New Zealand trampers, their activities and injuries.

Lobb B.

Psychology Department, Tamaki Campus, The University of Auckland, Private Bag 92019, New Zealand. b.lobb@auckland.ac.nz

Abstract

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)

Wilderness Environ Med. 2009 Fall;20(3):250-6.

The impact of footwear and packweight on injury and illness among long-distance hikers.

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:

• Wilderness Environ Med. 2010 Jun;21(2):178-9; author reply 179.

Abstract

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.