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Hip pads reduce the overall risk of injuries in recreational snowboarders
  1. Daichi Ishimaru1,
  2. Hiroyasu Ogawa1,
  3. Kazuhiko Wakahara2,
  4. Hiroshi Sumi3,
  5. Yasuhiko Sumi4,
  6. Katsuji Shimizu1
  1. 1Department of Orthopaedic Surgery, Gifu University, Graduate School of Medicine, Gifu, Japan
  2. 2Department of Orthopaedic Surgery, Ibi Kousei Hospital, Gifu, Japan
  3. 3Department of Orthopaedic Surgery, Sumi Memorial Hospital, Gifu, Japan
  4. 4Department of Neurosurgery, Sumi Memorial Hospital, Gifu, Japan
  1. Correspondence to Dr Hiroyasu Ogawa, Department of Orthopaedic Surgery, Gifu University, School of Medicine, 1-1, Yanagido, Gifu, Gifu 501-1194 Japan; h-ogawa{at}k7.dion.ne.jp

Abstract

Objective The purpose is to determine common injuries in recreational snowboarding as targets of preventive strategy and protective gear that reduces the overall risk of these injuries.

Methods The subjects comprised 5561 injured recreational snowboarders. On the basis of patients’ self-reporting form, ‘the common snowboarding injuries’ (cut-off point >2.0% in prevalence) were decided, and all injured snowboarders were categorised into two groups: common injuries and the other injuries (control). Several factors such as age, gender, self-reported skill level, experienced seasons, experienced days, previous snowboarding school attendance and the use of protective gears (helmet, elbow pads, wrist guards, backbone guard, hip pads and knee pads) were recorded. Multiple logistic regression analysis was conducted to investigate which type of protective gear reduced the overall risk of the common injuries.

Results The common snowboarding injuries consisted of eight types, in which distal radial fracture was the most common (17.7%), followed by head injury (9.4%) and clavicle fracture (6.5%). In univariate regression analysis, skill level, experienced seasons, experienced days and the use of hip pads and knee pads were manifested potential risk factors on the common injuries. In subsequent multivariate regression analysis, the use of hip pads was related with a lower overall risk of these common injuries (OR, 0.84; 95% CI, 0.75 to 0.95), specifically that of distal radial fracture and glenohumeral dislocation.

Conclusions The use of hip pads is recommended for snowboarders as it reduces the overall risk of common snowboarding injuries.

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Introduction

Since the population of snowboarders expanded worldwide in the 1990s, snowboarding injuries have become a major concern in the fields of sports medicine and traumatology.

The potential risk of snowboarding injuries is high in recreational and elite snowboarders.1 ,2 In recreational snowboarders, head,3 ,4 spinal,5 upper extremity6 and pelvic7 injuries have been reported as notable injuries in contrast to knee injuries of elite snowboarders.2 ,8 There are some reports about the effect of the use of helmets9 and wrist guards10 on the reduction of head and wrist injuries, and each type of protective gear may protect the user from certain snowboarding injuries. However, they may have some secondary adverse effects resulting in other injuries as wrist guards may simply shift injuries to proximal parts of the arm without any reduction in the overall injury rate.1012 In other words, which type of protective gear reduces the total risk of snowboarding injuries and makes snowboarding safer has been unknown.

To reduce the overall risk of injuries in recreational snowboarding, first of all, common snowboarding injuries should be targeted in prevention strategy. Then, a comprehensive study is necessary to investigate the effectiveness of various types of protective gears against common snowboarding injuries rather than a study to reveal the limited effects of each type of protective gear on a specific injury. The aim of this study was to determine common snowboarding injuries as target in prevention strategy, and to find protective gears that reduce the overall risk of these common injuries. Such protective gears might make snowboarding safer.

Materials and methods

This study included injured snowboarders who were admitted to the emergency ward of Sumi Memorial Hospital (Gujo, Gifu, Japan) during the four snowboarding seasons from 2007–2008 to 2010–2011. Sumi Memorial Hospital is the only primary emergency centre in the Oku-Mino area, which has 12 ski resorts, in Gifu Prefecture, Japan, so virtually everyone injured in this area is referred to our hospital. Therefore, the present study of injured snowboarders who have received primary treatment in this hospital can provide the aetiology of snowboarding injuries in the Oku-Mino area.1 ,7

A standard form was used to record personal data (age, gender), as well as information on self-reported skill level, the total number of experienced snowboarding seasons, the total number of experienced days for snowboarding, previous snowboarding school attendance (yes/no) and the use of protective gear at the time of injury (helmet, elbow pads, wrist guards, backbone guard, hip pads and knee pads). Self-reported skill level was stratified into three levels, based on experience, as described in previous reports1 ,7: beginner, intermediate and expert. The interviews were given by the medical staff of the emergency centre in a waiting or emergency room in the hospital before the injured snowboarders took their physical examinations. If the injured snowboarders were unable to take interviews, friends or relatives who were at the accident scenes provided information for them as much as possible.

In this study, ‘common snowboarding injury’ was defined according to prevalence of more than 2% of all injuries. In the case of snowboarders with multiple trauma, only the most severe injury was included in this analysis. All injured snowboarders were categorised into common injury and the other injuries (control) groups.

Pearson's χ2 test was used to compare age, gender, skill level, experienced seasons, experienced days, snowboarding school attendance and the prevalence of protective gear use between the groups. Univariate and multivariate logistic regression analyses were conducted to estimate the risk factors of snowboarding injuries. For explanatory variables, the characteristics of injured snowboarders were coded by using a standard form as follows: age (<20, 20–30 and >30 years old), gender (male/female), self-reported skill level (beginner, intermediate and expert), experienced seasons (1, 2–5, 6–10 and >10 seasons), experienced days (1–10, 11–50, 51–100 and >100 times), previous snowboarding school attendance (yes/no) and whether or not use of protective gear at the time of injury (helmet, elbow pads, wrist guards, backbone guard, hip pads and knee pads). Continuous explanatory variables such as age, experienced seasons and experienced days were stratified in a manner of preserving linearity of the natural logarithm of the OR. Initially, the effect of each single potential risk factor was assessed by univariate logistic regression analysis. For snowboarding injuries as a whole, the effect of more than one potential risk factor was considered by entering all explanatory variables with a univariate p value of 0.20 or less into a multivariate logistic regression analysis, using likelihood ratio tests and stepwise selection of the factors. p Values of less than 0.05 or an OR with a 95% CI that did not include one were considered as significant. Interaction effects between two explanatory variables were assessed by using the variance inflation factor values, and none of interaction effects among explanatory variables were found. All statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS) for Windows, V.16.0 (SSPS, Chicago, Illinois, USA).

Results

Of the 5561 snowboarding injuries recorded in the study period, the most common injuries, which were severe to need professional physicians, were found by a cut-off at a prevalence of 2%. Distal radial fracture was the most common injury in 17.7%, followed by head injury (including concussion and intracranial hemorrhage) in 9.4%, clavicle fracture in 6.5%, humerus fracture in 5.9%, glenohumeral dislocation in 5.2%, spinal burst and compression fractures in 4.2%, elbow dislocation in 3.1% and acromioclavicular dislocation in 2.5% (table 1). These injuries totaled 3035 cases, accounting for 54.6% of all snowboarding injuries and the prevalence of multiple injuries was 5.5% (307 snowboarders).

Table 1

Common snowboarding injuries

In table 2, the characteristics of snowboarders with common injuries are compared with those of the injured control. Self-reported skill level, experienced seasons and experienced days were found to be significantly different between the groups; snowboarders with common injuries had the higher prevalence of ‘beginner’ in skill level, ‘1 to 5’ in experienced seasons and ‘1–50’ in experienced days, compared with the control group (p<0.001, each). The prevalence of equipped protectors is compared between the groups (table 3). The prevalence of hip pads and knee pads use was significantly higher in the control group than in the common injury group (p<0.001, each).

Table 2

Factors related with the common snowboarding injuries

Table 3

Protectors equipped by snowboarders with common injuries and the injured controls

To investigate the risk factor of common snowboarding injuries, multiple logistic regression analyses was conducted for variable factors in the common injury and control groups (table 4). The potential risk factors found by univariate logistic regression analysis were skill level, experienced seasons, experienced days and the use of hip pads and knee pads, whereas factors such as age, gender, previous snowboarding school attendance, helmet use, elbow pad use, backbone guard use and wrist guard use did not qualify as potential risk factors. The use of hip and knee pads was associated with a lower risk of the common injuries (OR, 0.78 and 0.79; 95% CI, 0.70 to 0.87 and 0.70 to 0.91, respectively), after adjusting for potential risk factors (skill level, experienced days, experienced seasons and protective gear), only the use of hip pads was associated with a lower risk of these injuries (OR, 0.84; 95% CI, 0.75 to 0.95). These results showed that only the use of hip pads reduced the risk of the overall common injuries.

Table 4

OR for common snowboarding injuries (n = 5561)

Next, to investigate which risk of common injuries the use of hip pad actually reduced, multiple logistic regression analysis was conducted to analyse the variables between each common injury and the other injuries in the same statistical method as above. In brief, all injured snowboarders were reclassified into two groups consisting of each common injury and the other injuries (control), and logistic regression analysis between the variables and each common injury was performed. This analysis was done for every common injury. The OR of hip pad use was derived from analysis of each common injury (table 5; the data of the other risk factors are not shown). The result showed that the use of hip pads was related with reduced risk of distal radial fracture and glenohumeral dislocation (OR, 0.85; 95% CI, 0.73 to 0.99 and 0.61; 0.45 to 0.81, respectively), but not related with increased risk of any common injuries. These results strongly suggest that the use of hip pads can reduce the risk of frequent distal radial fractures and glenohumeral dislocations without any adverse effect, resulting in the reduction of the overall risk of the common snowboarding injuries.

Table 5

OR of hip pad for each common snowboarding injury (n = 5561)

Discussion

This study, which was applied to more serious injuries, showed that the most common snowboarding injuries were distal radial fracture, head injury, clavicle fracture, humerus fracture, glenohumeral dislocation, spinal burst and compression fractures, elbow dislocation and acromioclavicular dislocation. Under the condition of these injuries as the common injuries, the statistical analysis indicates that the use of hip pads is associated with reduced overall risk of the common injuries in contrast to the other types of protective gear. Moreover, this reduction might be attributed to the reduction of the risk of distal radial fracture and glenohumeral dislocation.

The positive effect of wrist guard and helmet use on wrist and head injuries has been reported while the use of wrist guard has the adverse effects on the development of upper arm injuries.1012 Fundamentally, these discussions may arise from the fear that protective gears may increase the rate of other snowboarding injuries although they may reduce specific injuries, such as wrist injuries for wrist guards. In our opinion, reduction in the overall risk of common snowboarding injuries is necessary to make snowboarding safer, and interestingly, our results indicate that hip pad is the only effective protective gear that reduces the overall risk of common injuries. To our knowledge, the effect of hip pads on the snowboarding injuries has not been reported.

Snowboarders tend to fall forward or backward when they lose their balance, either hitting the occipital region without any defending action13 or using an outstretched arm to break the fall.14 The upper body region suffers a greater force with the locked feet as the bearing, resulting in head or upper-extremity injuries. This force to the upper body region increases further if it is farther from the feet. Therefore, with regard to the protective effect of hip pads, we speculate that hip pads can buffer the force to the upper body region in a backward fall by allowing snowboarders to touch the ground with their hips before their upper bodies directly hit the ground. Supporting this theory, the use of hip pads was significantly associated with a lower risk of distal radial fracture and glenohumeral dislocation. In general, distal radial fracture frequently occurs when the hands impact the ground after falling,15 and glenohumeral dislocation is mostly caused by the force of shoulder abduction, extension and external rotation.16 ,17 Snowboarders falling backward are easily assumed to reflexively take these actions to defend themselves. From these mechanisms, it is also reasonable that the use of hip pads reduces the risk of these injuries.

There are some limitations associated with this study. First, it did not consider the effect of protective gear on life-threatening injuries, due to their uncommonness. Spinal cord, thorax, and abdomen injuries are life-threatening, so they should be considered as well as common injuries as the target of protective gear. Second, it is likely that an injured snowboarder, particularly when sustaining minor trauma, might not seek immediate medical treatment (the so-called bypass-effect).18 Therefore, the actual prevalence of relatively severe injuries is overestimated. Third, the data of characteristics of injured snowboarders contains self-reporting bias and recall bias to some degree due to the self-reporting design, as it has been reported that self-assessment for skiing or snowboarding ability is difficult.19 Finally, recent research suggests that different wrist guards have different biomechanical properties at the level of the distal radius and below.20 However, as the material, design and manufacturer of protective gears were not investigated in this study, our results are indicative of the overall effects of a variety of protective gears.

This is the first report that comprehensively discusses the relationship between several types of protective gear and snowboarding injuries. The results suggest that the use of hip pads reduces the overall risk of common snowboarding injuries, and therefore it should be recommended for snowboarders.

What this study adds

  • Hip pad is the protective gear that reduces the overall risk of common snowboarding injuries. Therefore, it should be recommended for snowboarders.

Acknowledgments

This study was supported by grants from the Japanese Orthopaedic Society for Sports Medicine (2012).

References

View Abstract

Footnotes

  • Contributors Authors’ contributions to this manuscript are the following: writing the manuscript by DI and HO; study design by HO, HS and KW; data analyses by DI and HO; and interpretation of the data by DI, HO and KS.

  • Competing interests None.

  • Patient consent Obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • ▸ References to this paper are available online at http://bjsm.bmjgroup.com

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