Lessons from the Winter Paralympic Games disclosing the epidemiology of winter sports injury in paralytic athletes: a meta-analysis.

BACKGROUND: In this study, the incidence rate of the injury in Winter Paralympic Games was summarized. Besides, to testify the underlying factors of injury incidence heterogeneity, the difference of these events incidence between different Paralympic Winter Games was investigated by meta regression analysis.
METHODS: Electronic databases were searched for full-text publications on sports related injury in Winter Paralympic Games. And meta-regression was used to analyze the heterogeneity.
RESULTS: Four studies were included. The incidence of sports related injury was 0.21 (95% CI 0.15-0.31) in all items, 0.22 in female athletes (95% CI 0.12-0.32), and 0.21 in male athletes (95% CI 0.11-0.30), respectively. The incidence of sports related injury was 0.10 (95% CI 0.08-0.12) in alpine skiing, 0.01 (95% CI 0-0.02) in Nordic skiing, and 0.22 in sledge hockey (95% CI 0.05-0.40). Meta-regression suggested the year and the host country couldn't influence the injury incidence.
CONCLUSION: The present study summarized the incidence of sports related injury in Winter Paralympic Games, indicated similar injury risk between female athletes and male athletes, and accentuated the careful protection on sledge hockey. This study pointed out that sledge hockey with the highest risk of sports related injury should draw great attention to improve the corresponding protective measures to decrease its injury probability.

Background

Paralympic athletes could be divided into six groups: limb defects, cerebral palsy, spinal cord related disabilities, visual impairment, intellectual impairment or a series of physical disorders that do not belong to aforementioned categories. These physical defects make it an unusual demand for medical resources for thousands of Paralympic athletes to keep healthy when participating in elite competitions. The improvement of physical fitness of disabled athletes is of great significance to reduce sports related risk. For these populations, the prevalence of risk factors may be very high [1]. Being anxious about the physical disadvantage, paralytic athletes were regarded to be susceptible to sports injury. However, from study of Clarsen et al., the incidence of sport injury seemed to be comparable between Winter Paralympic athletes and Winter Olympic athletes [2]. Among winter sports, alpine skiing, Nordic skiing, and sledge hockey were extensively regarded as the 3 most popular items in disabled athletes [3]. Meanwhile, injury risk of these winter sports items within the paralytic athlete community are frequently documented. It was reported that the injury incidence seemed to increase from the 2002 Winter Paralympic Games to the 2010 Winter Paralympic Games (the total injury incidence rate were 8.4%, 9.4%, and 24%, respectively) [4]. From a prospective injury surveillance study, patterns of the injury among winter Paralympians were similar to able-bodied athletes under the comparable competing disciplines, and most of these injuries seemed to be acute injury involved in alpine skiing and sledge hockey, including sprains (32%), fractures (21%), and strains and lacerations (14% each) during the Salt Lake 2002 Winter Paralympic Games [5]. The injury experience at the 2010 Vancouver winter Paralympic games suggested that the total injury incidence was 23.8%, including 34% of all sledge hockey athletes, 22% of alpine ski racers, 19% of Nordic skiers, and 18% of wheelchair curling athletes [4]. Lessons from the Sochi 2014 Winter Paralympic Games disclosed that there was a significantly higher incidence rate recorded in alpine skiing in comparison with cross-country skiing, ice sledge hockey or wheelchair curling [4]. Most recently, another prospective cohort study reported high incidence of athlete injuries at the Pyeongchang 2018 Paralympic Winter Games [6]. In this study, 567 athletes from 49 countries were monitored, and the total injury incidence rate still stayed in high level of 20.9%. Among them, the newly added sport item of Para snowboard contributed to the highest injury incidence rate.

Wilson et al. suggested a home advantage effect in the Winter Paralympic Games at country level, especially in alpine skiing and cross country skiing. Besides, they also argued that in comparison with the Winter Olympic Games, home advantage in the Winter Paralympic Games was generally more pronounced [7]. Accordingly, effects of home advantage in the Winter Paralympic Games should be investigated further. Previously published studies reported serial heterogeneous data of injury incidence. In this study, the incidence rate of the injury in Winter Paralympic Games was summarized. Besides, to testify the underlying factors of injury incidence heterogeneity, the difference of these events incidence between different Paralympic Winter Games was investigated by meta regression analysis. Based on susceptibility of different kinds of sports related injury in Winter Paralympic Games, more direct measures are supposed to take to specifically target to a certain sport item with the highest risk of sport related injury.

In order to protect paralytic athletes from winter sports related injury, assistive equipment is Technology could significantly influence sports performance in Paralympic winter sports in terms of some auxiliary instruments such as specialized prostheses, crutch skis or outriggers (in lieu of poles), and sport-specific wheelchairs [8].

Fundamental to keep persons safe when participate and compete in winter sport activities. Additionally, finding out which sport activity lead to the most events of injury is so important that the industry could be more focused to research and develop corresponding safeguard instruments.

Methods

Search strategy

This meta-analysis is based on instruction of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Electronic databases (PubMed, Embase, Web of Science, Ovid, EBSCO, clinicaltrials.gov and the Cochrane library) was searched before November 1st, 2021. Terms used in publications retrieval were: sports injury, paralytic athletes, sports medicine, Winter Paralympic Games, disabled athletes, etc.. No restriction of language were imposed.

Study selection criteria and data extraction

Two researchers independently searching the electronic database in accordance with the inclusion/exclusion criteria. The third investigator was introduced to make the final judgement. The inclusion criteria included: (1) study objects: winter sports injury in Winter Paralympic Games; (2) population: paralytic athletes; (3) study design: observational cohort. The exclusion criteria included: (1) sports injury in Winter Olympic Games; (2) sports injury in Summer Paralympic Games; (3) investigating the incidence of all illness instead of pure sports injury. The methodological quality of the studies included was assessed using an 11-item checklist which was recommended by Agency for Healthcare Research and Quality (AHRQ). An item would be scored ‘0’ if it was answered ‘NO’ or ‘UNCLEAR’; if it was answered ‘YES’, then the item scored ‘1’. Article quality was assessed as follows: low quality = 0–3; moderate quality = 4–7; high quality = 8–11 [9].

Data synthesis and analysis

Endnote (Version 7.6, Thomson Reuters, Inc., Philadelphia, PA) bibliographic software was used to create an electronic library of citation. Two investigators used a standardized tool to extract the following data from each study: first author’s name, year of publication, country, number of study patients, baseline characteristics of included athletes, and sports related injury events. We used the recommended method to assess the risk of bias for included studies.

Statistics

Data were analyzed using Stata version 12.0 (Stata Corporation, College Station, TX, USA). Before the data were synthesized, we first test the heterogeneity between the studies using Q chi-square test. I2 statistic was used to describe the percentage of the variability that attributed to heterogeneity across the studies rather than the chance. Studies with an I2 statistic of < 50% was considered to have no, low degree of heterogeneity. Pooled estimates were calculated to summarize the injury incidence rate. Subgroup analysis was performed to explore the potential sources of heterogeneity. Meta-regression analysis was applied to testify the changes of sports injury incidence in different session of Winter Paralympic Games. The assessment of publication bias was evaluated by using Egger and Begger test. A 2-tailed p value less than 0.05 was judged as statistically significant, except where otherwise specified.

Results

Literature search and general description of included studies

Articles reported the epidemiology of sports injury in four different Winter Paralympic Games were finally included to meet the inclusion/exclusion criteria. And the process flow diagram of publication screening and filtration was shown in Fig. 1. Data of disabled athletes during each Winter Paralympic Games were collected, and the overview of included studies and demographic characteristics of athletes were described (Table 1). The literature quality evaluation was depicted in Table 2.

Fig. 1

Process flow diagram of publication screening and filtration

Table 1

Characteristics of included studies and athletes’ demography at baseline

Author	Host year	Host country	N of athletes	Female (%)	Age (min, max)	Major sports events	Study design
Webborn et al	2002	United States	416	88 (21.2)	33 (17–58)	Alpine skiing, Nordic skiing, and Sledge hockey	Observational study
Webborn et al	2010	Canada	505	124 (24.6)	34 (19–52)	Alpine skiing, Nordic skiing, and Sledge hockey	Observational study
Derman et al	2014	Russia	547	129 (23.6)	31 (14–63)	Alpine skiing, Nordic skiing, and Sledge hockey	Observational study
Derman et al	2018	South Korea	567	134 (23.6)	32 (15–67)	Alpine skiing, Nordic skiing, and Sledge hockeyzz	Observational study

Table 2

Quality assessment of literatures by AHRQ scale

Author	1	2	3	4	5	6	7	8	9	10	11
Webborn, et al. (2002)	Yes	Unclear	Unclear	Yes	No	Yes	Unclear	Yes	Unclear	Yes	Unclear
Webborn et al. (2010)	Yes	Unclear	Unclear	Yes	No	Yes	Unclear	Yes	Unclear	Yes	Unclear
Derman et al. (2014)	Yes	Unclear	Unclear	Yes	No	Yes	Unclear	Yes	Unclear	Yes	Unclear
Derman et al. (2018)	Yes	Unclear	Unclear	Yes	No	Yes	Unclear	Yes	Unclear	Yes	Unclear

(1) Define the source of information (survey, record review); (2) List inclusion and exclusion criteria for exposed and unexposed subjects (cases and controls) or refer to previous publications; (3) Indicate time period used for identifying patients; (4) Indicate whether or not subjects were consecutive if not population-based; (5) Indicate if evaluators of subjective components of study were masked to other aspects of the status of the participants; (6) Describe any assessments undertaken for quality assurance purposes (e.g., test/retest of primary outcome measurements); (7) Explain any patient exclusions from analysis; (8) Describe how confounding was assessed and/or controlled; (9) If applicable, explain how missing data were handled in the analysis; (10) Summarize patient response rates and completeness of data collection; (11) Clarify what follow-up, if any, was expected and the percentage of patients for which incomplete data or follow-up was obtained

All sports related injury in Winter Paralympic Games

The incidence of sports related injury in all items in Winter Paralympic Games was 0.21 (95% CI 0.15–0.31) (Fig. 2A). Besides, the injury incidence of all sports item was further calculated in female athletes (pooled incidence rate = 0.22, 95% CI 0.12–0.32) and male athletes (pooled incidence rate = 0.21, 95% CI 0.11–0.30), respectively (Fig. 2B, C). In general, there existed heterogeneity among four different Winter Paralympic Games, and meta regression analysis suggested that the year and the host country couldn’t influence the injury incidence of all sports items (OR = 1.01, 95% CI 0.65–1.57) (Fig. 2D). In addition, the effects of the year and the host country of different Winter Paralympic Games on sports injury showed similar pattern in both female athletes (OR = 1.01, 95% CI 0.72–1.42) and male athletes (OR = 1.01, 95% CI 0.67–1.54) (Fig. 2E, F.

Fig. 2

All sports related injury in Winter Paralympic Games: any sports related injury in all athletes (A); any sports related injury in female athletes (B); any sports related injury in male athletes (C); meta regression analyzing the effects of host year and host country on sports related injury in all athletes (D); meta regression analyzing the effects of host year and host country on sports related injury in female athletes (E); meta regression analyzing the effects of host year and host country on sports related injury in male athletes (F)

Subgroup analysis of the sports related injury in three terms

Among all events of Paralympic Winter Games, Alpine skiing, Nordic skiing, and Sledge hockey are three major items, and their related sports injury have been frequently reported. Therefore, subgroup analysis aimed to analyze the difference of injury incidence in Alpine skiing, Nordic skiing, and Sledge hockey, respectively.

Alpine skiing

The incidence of sports related injury in alpine skiing was 0.10 (95% CI 0.08–0.12) (Fig. 3A). Additionally, meta-regression disclosed that the year and the host country of Paralympic Winter Games had no effects on the incidence of alpine skiing related injury (OR = 1.07, 95% CI 0.74–1.57) (Fig. 3B).

Fig. 3

Sports related injury in alpine skiing: the incidence of sports related injury in alpine skiing (A); the effects of host year and host country on sports related injury (B)

Nordic skiing

The incidence of sports related injury in Nordic skiing was 0.01 (95% CI 0–0.02) (Fig. 4A). In meta-regression analysis, the year and the host country of Paralympic Winter Games failed to influence the incidence of Nordic skiing related injury (OR = 1.14, 95% CI 0.48–2.69) (Fig. 4B).

Fig. 4

Sports related injury in Nordic skiing: the incidence of sports related injury in Nordic skiing (A); the effects of host year and host country on sports related injury (B)

Sledge hockey

The incidence of sports related injury in sledge hockey was 0.22 (95% CI 0.05–0.40) (Fig. 5A). In meta-regression analysis, the year and the host country of Paralympic Winter Games failed to influence the incidence of Nordic skiing related injury (OR = 1.11, 95% CI 0.78–1.57) (Fig. 5B).

Fig. 5

Sports related injury in sledge hockey: the incidence of sports related injury in sledge hockey (A); the effects of host year and host country on sports related injury (B)

Publication bias

Begg’s test indicated a symmetrical distribution of included publications (p = 0.089) by a funnel plot (Fig. 6), suggesting no publication bias among articles included in this study.

Fig. 6

Funnel plot indicating the publication bias on included studies

Discussion

In this meta-analysis, four eligible studies were included. The incidence of sports related injury was 0.21 (95% CI 0.15–0.31) in all items, 0.22 in female athletes (95% CI 0.12–0.32), and 0.21 in male athletes (95% CI 0.11–0.30), respectively. The incidence of sports related injury was 0.10 (95% CI 0.08–0.12) in alpine skiing, 0.01 (95% CI 0–0.02) in Nordic skiing, and 0.22 in sledge hockey (95% CI 0.05–0.40). Meta-regression suggested the year and the host country couldn’t influence the injury incidence. The present study summarized the incidence of sports related injury in Winter Paralympic Games, indicated similar injury risk between female athletes and male athletes, and accentuated the careful protection on sledge hockey. From this study, susceptibility of different kinds of sports related injury in Winter Paralympic Games fluctuated among different time points. This could be probably owing to the dynamic balance between the evolution of sports competition difficulty and the development sports protective equipment.

The past dozens of years witnessed the progression of auxiliary equipment, prosthetic device, and other personal technical wearing in Paralympic winter sports. The well designed sport equipment is fundamental for a person with a disability to participate and compete in winter sport activities. To improve the technology which influenced sports performance in Paralympic winter sports, such as specialized prostheses, crutch skis or outriggers (in lieu of poles), and sport-specific wheelchairs (such as the sit-ski) [8]. Considering the high incidence of kinds of injury in paralympic winter sports, corresponding strategy should be made to tackle with these problems. Lee et al. tried providing accessibility manual based on the fundamental data to ultimately serve as a cornerstone for accessing venues and ways to improve winter paralympic sporting event management [10]. The newly added item of winter sport should draw lots of attention for the reason of lacking of related experience of medical preparation [6]. Mental health of athletes in Paralympics winter games should also draw our attention. Professional psychologists could help paralytic athletes to develop mental skills to manage the unique stressors of the Paralympics to increase the odds of having superior performances [11]. Illustrating the injury pattern in previously held Paralympics winter games would help to throw great light on future injury prevention guidance, especially for the upcoming Beijing 2022 Paralympic Winter Games. Paralympic athletes with unique pre-existing medical conditions seemed to be susceptible to increased risk of illness, and it was reported that the incidence rate of illness (per 1000 athlete-days) in Paralympic athletes is high (18.7) in Winter Paralympic Games [4]. Therefore, illness, as well as injury should also be centered on and possible interactions should be investigated. Derman et al. described the high incidence rate and illness burden at the Pyeongchang 2018 Paralympic Winter Games, and they found the respiratory system problem as one the most frequently involved illness in Paralympic athletes [12]. Besides, the highest rates of illness were reported for the respiratory system at the Sochi 2014 Winter Paralympic Games [4]. However, the epidemiology of illness indicated that Paralympic athletes had higher illness incidence rates compared with Olympic athletes at similar competing items [4]. Timely identification and intervention of the sport injury by therapeutic bodily assistive devices enabled beyond-the-normal body abilities and had an impact on participation of people with disabilities in sport at all levels and on the self-identity of athletes with disabilities [13]. Currently accumulated evidence in the Winter Paralympic Games should arouse considerations in the development of equipment standards for paralympic athletes. All in all, Paralympic medicine should draw lots of attention, and solutions should be applied to protect paralytic athletes from sports related injury in winter adaptive sports.

Limitations

Our study accentuated the critical need of the effective operation of the assistive device. However, further investigation should focused on assessing the efficiency of different equipment in some specific sport item. The included studies were only characterized with single cohort study, and they didn’t have control group. Besides, the number of eligible articles were too small, and thus sensitivity analysis couldn’t be applied.

Conclusion

The present study summarized the incidence of sports related injury in Winter Paralympic Games, indicated similar injury risk between female athletes and male athletes, and accentuated the careful protection on sledge hockey. Meta-regression suggested that the host year and the host country didn’t influence the incidence of sports related injury Winter Paralympic Games. From this study, dynamic changes of sports related injury in Winter Paralympic Games were disclosed, and this study proposed that sledge hockey, which is accountable for the largest amount of sports related injury, should draw attentions to improve the corresponding protective measures to decrease its injury probability. Our study could possibly indicate additionally how the constantly improving supply of aids for competitive athletes can and should also be used for the rehabilitation and life of disabled non-athletes or recreational athletes in order to be able to increase the quality of life but also to ensure and support the necessary preventive and therapeutic motor activities. Moreover, this study suggested that no difference of susceptibility of sports injury in term of different gender.