Paralympic Sports Medicine and Science
Descriptive Epidemiology of Paralympic Sports Injuries Nick Webborn, MB, BS FSEM (UK), Carolyn Emery, PT, PhD Abstract: Paralympic sports have seen an exponential increase in participation since 16 patients took part in the first Stoke Mandeville Games on the opening day of the 1948 London Olympic Games. More than 4,000 athletes took part in the London 2012 Paralympic Games. Few sporting events have seen such rapid evolution. This rapid pace of change also has meant challenges for understanding the injury risks of participation, not only because of the variety of sports, impairment types, the evolution of adapted equipment but also because of the inclusion of additional impairment types and development of new sports over time. Early studies were limited in scope but patterns of injuries are slowly emerging within Winter and Summer Paralympic sports. The IPC’s London 2012 study is the largest to date with a prospective cohort study involving 49,910 athlete-days. The results identified large differences across sports and highlighted the need for longitudinal sport specific studies rather than solely games-time studies. This will require collaboration with international sports federations to examine injury patterns and risk factors for injury in this population to appropriately inform injury prevention strategies. Further studies will also need to address the impact of sporting participation, injury, and future health. PM R 2014;6:S18-S22
INTRODUCTION Paralympic sports have seen an exponential increase in participation since 16 patients took part in the first Stoke Mandeville Games on the opening day of the 1948 London Olympic Games. More than 4000 athletes took part in the London 2012 Paralympic Games to packed audiences and worldwide television coverage. Few sporting events have seen such a rapid evolution. This rapid pace of change also has meant challenges for understanding the injury risks of participation because of inclusion of additional impairment types and development of new sports. In 1960, the International Stoke Mandeville Games were held in Rome and since that time, the Games have been held in the country selected for the Olympic Games where possible, save for financial or political reasons. In 1976, in Toronto, the Games included visually impaired and amputee athletes for the first time, and the Games were known as the Olympiad for the Physically Disabled. In 1980, in Arnhem, athletes with physical disabilities not fitting into the historical disability groups (Les Autres; fr. “the others”) or with cerebral palsy also were included. The International Paralympic Committee (IPC) was founded in 1989, and since 1994 the management of the Paralympic Games has been administered byr the IPC. Although athletes with intellectual disabilities have participated in some Paralympic Games, they are not included in this review. The data for this review were primarily published articles and reports from a literature search of PubMed and SPORTDiscus; however, information from Congress proceedings and both published and unpublished articles known to the authors but not identified through these database sources also were evaluated. English-language articles were used primarily, but some German texts were incorporated where translation could be performed. Search terms involved permutations and combinations of Paralympic, injury, cerebral palsy, visually impaired, wheelchair, disability, and sport. A variety of methodologic limitations, which confound the interpretability of the findings, were evident in the literature, particularly in earlier studies. Factors included a lack of standard definitions for reportable injury and injury details, short study timeframes, PM&R
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1934-1482/14/$36.00 Printed in U.S.A.
N.W. The Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK. Address correspondence to: N.W.; e-mail: [email protected] Disclosure: nothing to disclose C.E. University of Calgary, Alberta, Canada Disclosure: nothing to disclose Submitted for publication January 31, 2014; accepted June 10, 2014.
ª 2014 by the American Academy of Physical Medicine and Rehabilitation Vol. 6, S18-S22, August 2014 http://dx.doi.org/10.1016/j.pmrj.2014.06.003
PM&R
poor or absent exposure data, use of self-report surveys that did not include a confirmed medical diagnosis, and small sample sizes. In addition, the unique grouping of sports by disability makes obtaining a clear picture of injury risk and risk factors in Paralympic sport complicated. For example, when investigating the risk of injury related to a particular sport, of the 27 Paralympic sports (22 summer [planned in year 2016] and 5 winter), some are participated in by athletes with different impairments (athletics: spinal cord injured, visually impaired, amputee, and cerebral palsy), some are unique to particular disability categories (goalball: visually impaired; wheelchair rugby: athletes with impairment in all 4 limbs), some are modified by rules (judo) or equipment (sit-ski; sledge hockey) for particular classes of athletes, and some involve multiple categories of disability on the same team (basketball). Caution also may be required intepreting studies if the investigation is focused on the risks related to a particular class of disability across different sports. For example, a lower limb amputee athlete may compete with a prosthesis for track athletics or cycling, without a prosthesis for swimming or high jump, or in a wheelchair for sports such as basketball and tennis. Athletes with cerebral palsy may be ambulant or wheelchair users depending upon the degree of disability. Some more recent studies have used a combination of impairment and sport specificity to limit these confounders but so far have relatively few athlete numbers, and the results need to be treated with some caution [1-3]. Changes in professionalism and level of participation in disability sport impose a further difficulty in interpreting the available data. In the 1970s and 1980s, it was not uncommon for individual athletes to participate in multiple sports, even at the Paralympic Games. In a survey of 128 athletes with disabilities, Curtis and Dillon [4] found 79% were competing in track athletics, 71% in wheelchair basketball, 57% in road racing, and 60% in field events in athletics. This occurrence would be rare in elite disability sports now. Technology in the form of lightweight, high tensilestrength materials and improved designs for wheelchairs and prostheses for different populations of Paralympic athletes have changed performance parameters and injury risk characteristics during the past 2 decades. In addition, training protocols and access to specialized trainers, coaches, and medical personnel have changed during the past few decades. As such, comparisons between injury patterns seen 20-30 years ago and those seen currently may not be appropriate. In addition, findings from older research articles in this area may not reflect the current position in elite Paralympic sport. Thus, a broad overview of injury patterns in Paralympic sports potentially loses sight of risk and risk factor relationships in specific sport/disability interactions, and the small numbers in any particular combination renders analyses and conclusions unstable. In an attempt to address some of these issues, the IPC’s Injury Surveillance System
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(ISS) was implemented during the 2002 Salt Lake City Winter Paralympic Games and has continued at all subsequent Winter Paralympic Games. The first summer games injury and illness survey was during the London 2012 Paralympic games and was the first study to report on sport-specific injury incidence rates considering exposure to risk.
WHO IS AFFECTED BY INJURY? A comparison of injury rates (IRs) reported in prospective and retrospective research is summarized in Table 1 [5-17]. As noted previously, some studies involved multiple disability groups and some covered only individual disability groups; sports surveyed ranged from the full complement of summer Paralympic sports to individual sports. Few studies reported incidence rates because of the omission of exposure data. Interpretability of the results often is challenging in the absence of a reportable injury definition or by the variation of the definition between studies. Invariably, the definition will influence both the data collected and the risk assessment of the sports studied. For example, several retrospective questionnaire studies included minor soft-tissue injuries (eg, blisters or abrasions for which no medical attention was sought) whereas other research, which was based on the organizing committee’s medical services at Paralympic Games, did not include minor soft-tissue injuries.
Summer Sports The first study to attempt to quantify exposure data was a 2-year prospective study by Ferrara et al [8] of 319 multidisability athletes in summer Paralympic sports. An overall IR of 9.3 injuries/1000 participation hours was reported; however, no sport-specific details were provided, and self-reported symptoms have inherent limitations. The London 2012 injury survey13 captured data from 3565 athletes (84% compliance by athletes) from 160 delegations (98% compliance by delegation) during training and competition in the 20 summer sports. A total of 49,910 athlete-days were monitored during which a total of 633 injuries in 539 athletes were documented. The overall injury incidence rate was 12.7 injuries/1000 athlete days (95% confidence interval [95% CI] 11.7-13.7). The overall incidence proportion was 17.8 injuries/100 athletes (95% CI 16.5-19.0); however, there were marked variations by sport, with the greatest injury rates in Football 5-a-side (IR 22.4 injuries/1000 athlete-days), Goalball (IR 19.5 injuries/ 1000 athlete-days), Powerlifting (IR 19.3 injuries/1000 athlete-days), wheelchair fencing (IR 18.0 injuries/1000 athlete-days), and wheelchair rugby (IR 16.3 injuries/1000 athlete-days). Sports with the lowest IRs included sailing (IR 4.1 injuries/1000 athlete-days), rowing (IR 3.9 injuries/ 1000 athlete-days), and shooting (IR 2.2 injuries/1000 athlete-days).
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Table 1. Distribution of injury onset: acute vs chronic Author Summer sports Curtis and Dillon [4]*yzx Ferrara and Davis [5]* Burnham et al [6]*yzx{ Richter et al [7]z Ferrara et al [8]*yzx{ Taylor and Williams [9]* Reeser [10]yx Ferrara et al [11]*yzx{ Nyland et al [12]*yzx Magno e Silva et al [1]{ Magno e Silva et al [3]{ Magno e Silva et al [2]{ Willick et al [13]*yzx{ Mean Winter sports Ferrara et al [14]*yx Webborn et al [15]*yzx{ Webborn [16]*yzx{ Webborn et al [17]*yzx{
Sample
Injuries (Frequency)
M:F, %
Type of Sport
Acute, %
Chronic, %
1200 19 151 75 426 53 89 1360 304 13 40 28 3565
128 19 108 27 137 38 41 1037 254 35 77 41 633
79:21 53:47 NR NR NR 77:23 All male NR NR All Male 70:30 68:32 66:34
Wheelchair sports Wheelchair sports Summer Paralympic Summer Paralympic Summer Paralympic Wheelchair racing Standing volleyball Multisport Summer Paralympic Football 5-a-side Track and field athletics Swimming Summer Paralympic
40 65 49 73 46 41 60 77 67 80 18 20 68 54
60 35 51 27 54 59 40 23 33 20 82 80 32 46
68 194 134 88 190 112 132
68 24 12 3 23 12 5
118
40
Alpine skiing Alpine skiing Ice sledge hockey Nordic skiing Alpine skiing Ice sledge hockey Nordic skiing Alpine skiing Ice sledge hockey Nordic skiing Wheelchair curling
50 91 83 50 78 64 80 45 40 40 0 56
50 9 17 50 22 36 20 55 60 60 100 44
Mean
78:22 79:21
79:21
75:25
NR ¼ not reported. *Spinal cordrelated disability. y Amputee. z Cerebral palsy. x Les Autres. { Visually impaired.
A separate study [18] describing injuries in 91 Polish Paralympians in Beijing (2008) and 100 in London (2012) reported an incidence rate of 29.8/1000 athlete-days (95% CI 22.1-37.6) in Beijing and only 15/1000 athlete-days (95% CI 9.0-21.0) in London. Three studies examining injury in elite Brazilian visually impaired athletes recorded longitudinal data during the period 2004-2008 in 3 separate sports but sample size is small and limited to one nation [1,3]. Allen [19] reported an injury prevalence of 6.3% in a survey of sailors with multiple disability types in the International Foundation for Disabled Sailing World Championship (n ¼ 24 teams). McCormick and Reid [20] reported the prevalence of injury in basketball (30.9%), track athletics (30.6%), and road racing (12.1%) in a retrospective study of wheelchair athletes; however, blisters and abrasions formed approximately 50% of these injuries, many of which did not require formal medical treatment.
Winter Sports Studies examining winter sports also included variation between reports on single events, such as Alpine skiing
compared with all winter Paralympic sports. A multicenter study describing injuries occurring in recreational skiers with a disability reported an injury incidence rate of 2 injuries/ 1000 skier days [21]. Webborn [16] reported comparative injury data by sport from 2 winter Paralympic Games (2002 and 2006) and found similar rates at both Games in each sport; however, the ISS captured sport injuries in 24% of all athletes participating in the 2010 Vancouver Winter Paralympic Games [17]. The injury risk was significantly greater than during the 2002 (9.4%) and 2006 (8.4%) Winter Paralympic Games, which may reflect improved injury surveillance methodology and data capture but also highlights the high risk of acute injury in alpine skiing and ice sledge hockey in particular. There were a total of 120 injuries among the 505 athletes (incidence proportion 23.8%, 95% CI 20.1-27.7). In Alpine skiing, 22% of competitors presented with an injury compared with 13% and 12% of competitors in 2002 and 2006, respectively. Downhill racing was the most likely cause of injury, with 4 new acute injuries occurring for every 100 race events. For ice sledge hockey, 34% of competitors presented with injury compared with 14% and 11% of competitors in 2002 and 2006, respectively. Nordic skiing and
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wheelchair curling have significantly lower injury rates at 18.6% and 18%, respectively.
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WHEN DOES THE INJURY OCCUR? Injury Onset
WHERE DOES INJURY OCCUR? Anatomical Location In studies involving wheelchair athletes, the upper limb, particularly the shoulder, is the most common site of injury, with a prevalence for shoulder injury ranging from 19% [20] across multiple wheelchair sports to 72% in female wheelchair basketball players [22]. However, Webborn and Turner [23] noted in their report on 244 British athletes seen during a 4-week period, including the build-up to, and competition in, a summer Paralympic Games that although the shoulder was the most common site of pain in wheelchair athletes (30%), the cervical and thoracic spine (59% and 8%, respectively) were the actual sites of pathology (resulting in referred pain to the shoulder) compared with 33% of specific shoulder pathology. In the London 2012 study [13], the distribution of injury by body part also was greatest in the upper limb irrespective of impairment type (50.2% of all injuries), with shoulder injuries being most prominent (17.7% of all). The knee was the most common injured region of the lower limb (7.9% of all injuries). In elite disabled standing volleyball players (including athletes with upper limb and lower limb impairments including amputation), Reeser [10] identified the foot and ankle as the most common site of injury (21%), followed by the shoulder (18%), wrist and hand (18%), and the knee (14%). In this study, the distribution of injury locations was not related to the type of disability. In a 4-year study examining injury in Brazilian visually impaired (n ¼ 13) footballers (soccer players) [1], the greatest proportion of injuries reported were lower limb (80%), head (8.6%), spine (5.7%), and upper limb injuries (5.7%). Webborn et al [15] noted that lower limb fractures were frequent in spinal cord-injured ice sledge hockey athletes and in standing athletes in Alpine skiing in the 2002 Winter Games. However, in the 2006 and 2010 Winter Games, only one lower limb fracture occurred in ice sledge hockey over both the Games compared with the 4 fractures seen in 2002 before the introduction of the regulation change on protective equipment and sledge height [17]. Athletes in seated Alpine classes consistently had more upper limb injuries in all 3 Winter Paralympics studied. Injuries to the head and neck in ice sledge hockey and Alpine events also were common. IRs in wheelchair curling appear consistently low across the 2 Games (2006 and 2010) in which the sport has been included. There were no recorded injuries in 2006. In 2010 although 9 of 50 (18%) curlers sought medical attention for musculoskeletal complaints, none of these was acute injuries, and 5 of the 9 encounters were for pre-Games nonsport-related symptoms.
Table 1 also presents the percent distribution of acute and chronic injuries in disability sport. here is approximately a 55:45 ratio of acute to chronic injuries reported in the literature for most summer and winter Paralympic sports; however, there is marked variation by sport as one would expect with differences between contact and endurance sports for example. This finding also may reflect when the injury data were collected, with competition surveys reporting more acute injuries [10,12,24] and longitudinal surveys reporting more chronic injuries [4,8].
WHAT IS THE OUTCOME? Injury Type In Summer Paralympic sports, the authors of a previous review [25] reported strains (mean ¼ 25.4%; range: 4%60%) and sprains (mean ¼ 22.8%; range: 3.7%-48%) to be the most common injury types. However, this finding varies greatly between studies. The use of self-report data in the majority of the studies raises questions about the validity of injury classifications in these works. The studies by Burnham et al [6] and Webborn et al [15], in which physician or therapist diagnosis was the basis for classification, may be considered more accurate. Three longitudinal studies [1-3] in visually impaired athletes in swimming, football 5-a-side, and track and field athletics reported injuries during a 5-year period in one national team squad. Two of the studies describe “muscle spasms” as the most common injury type but without further explanation as to whether this definition indicates muscle cramp, fatigue-related, or neurally mediated spasm. Thus, it remains unclear of the true nature of the problem and its significance for injury prevention. In the Winter Sports, contusions, fractures, and concussion are more prevalent because of the impact potential and speed. For example, in Ice Sledge Hockey in 2002 fractures comprised 33% of injuries. After modifications in regulations on protective equipment and sledge height, fractures accounted for 7.5% of all sledge hockey injuries in 2010. Only one of these fractures involved the lower limb. In Nordic and Alpine Skiing, there were 4 head injuries in the 2010 Winter Games, 3 of which prevented further participation in competition.
CONCLUSION There is significant variability in injury definitions, research designs, data collection methodology, and analytic approaches in the literature examining injury in disabled athletes during the past 2 decades. The IPC has supported the development of injury surveillance tools to ensure methodological rigor in examining injuries in the Paralympic Games
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that will hopefully lead to evidence informed safety and prevention practices in future game. Patterns of injuries are slowly emerging within Winter and Summer Paralympic sports, which highlights the need for longitudinal studies rather than solely games-time studies through collaboration with international sports federations. To further examine injuries and risk factors for injury in this population to inform injury prevention strategies, the IPC plans to continue the ISS during future summer and winter Paralympic Games while encouraging and supporting longitudinal, sport-specific studies.
REFERENCES 1. Magno e Silva MP, Morato MP, Bilzon JLJ, Duarte E. Sports injuries in Brazilian blind footballers. Int J Sports Med 2013;34:239-243. 2. Magno e Silva MP, Bilzon J, Duarte E, Gorla J, Vital R. Sport injuries in elite paralympic swimmers with visual impairment. J Athl Train 2013; 48:493-498. 3. Magno e Silva MP, Winckler C, Costa E Silva AA, Bilzon J, Duarte E. Sports injuries in paralympic track and field athletes with visual impairment. Med Sci Sports Exerc 2013;45:908-913. 4. Curtis KA, Dillon DA. Survey of wheelchair athletic injuries: common patterns and prevention. Paraplegia 1985;23:170-175. 5. Ferrara MS, Davis RW. Injuries to elite wheelchair athletes. Paraplegia 1990;28:335-341. 6. Burnham R, Newell E, Steadward RD. Sports medicine for the physically disabled: the Canadian team experience at the 1988 Seoul Paralympic Games. Clin J Sport Med 1991;1:193-196. 7. Richter KJ, Hyman SC, Adams-Mushett C, Ellenberg MR, Ferrara MS. Injuries to world class cerebral palsy athletes of the 1988 South Korea Paralympics. J Osteopath Sport Med 1991;7:15-18. 8. Ferrara MS, Buckley WE, McCann BC, Limbird TJ, Powell JW, Robl R. The injury experience of the competitive athlete with a disability: Prevention implications. Med Sci Sports Exerc 1992;24:184-188. 9. Taylor D, Williams T. Sports injuries in athletes with disabilities: Wheelchair racing. Paraplegia 1995;33:296-299. 10. Reeser JC. Injury patterns among elite disabled standing volleyball players. Int J Volleyball Res 1999;1:12-17.
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11. Ferrara MS, Palutsis GR, Snouse S, Davis RW. A longitudinal study of injuries to athletes with disabilities. Int J Sports Med 2000;21:221-224. 12. Nyland J, Snouse SL, Anderson M, Kelly T, Sterling JC. Soft tissue injuries to USA Paralympians at the 1996 summer games. Arch Phys Med Rehabil 2000;81:368-373. 13. Willick SE, Webborn N, Emery C, Blauwet CA, Pit-Grosheide P, Stomphorst J, et al. The epidemiology of injuries at the London 2012 Paralympic Games. Br J Sports Med 2013;47:426-432. 14. Ferrara MS, Buckley WE, Messner DG, Benedict J. The injury experience and training history of the competitive skier with a disability. Am J Sports Med 1992;20:55-60. 15. Webborn N, Willick S, Reeser JC. Injuries among disabled athletes during the 2002 Winter Paralympic Games. Med Sci Sports Exerc 2006;38:811-815. 16. Webborn AD. IPC injury survey Torino 2006. Paralympian. 2007;11. 17. Webborn N, Willick S, Emery CA. The injury experience at the 2010 Winter Paralympic Games. Clin J Sport Med 2012;22:3-9. 18. Gawronski W, Sobiecka J, Malesza J. Fit and healthy Paralympians— medical care guidelines for disabled athletes: a study of the injuries and illnesses incurred by the Polish Paralympic team in Beijing 2008 and London 2012. Br J Sports Med 2013;47:844-849. 19. Allen JB. Sports injuries in disabled sailing. In: Legg S, ed. Human performance in sailing conference proceedings: incorporating the 4th European Conference on Sailing Sports Science and Sports Medicine and the 3rd Australian Sailing Science Conference. Palmerston North, New Zealand: Massey University; 2003, 58. 20. McCormick DAR, Reid DC. Injury profiles in wheelchair athletes: Results of a retrospective survey. Clin J Sport Med 1991;1:35-40. 21. McCormick DP. Injuries in handicapped Alpine skiers. Physician Sportsmed 1985;13:93-97. 22. Curtis KA, Black K. Shoulder pain in female wheelchair basketball players. J Orthop Sports Phys Ther 1999;29:225-231. 23. Webborn AD, Turner HM. The aetiology of shoulder pain in elite Paralympic wheelchair athletes—the shoulder or cervical spine?. In: 5th Paralympic Scientific Congress. Sydney: International Paralympic Committee; 2000, 59. 24. Ferrara MS, Peterson CL. Injuries to athletes with disabilities: Identifying injury patterns. Sports Med 2000;30:137-143. 25. Webborn N. Paralympic sports. In: Dennis C, Peter H, Melissa S, eds. Epidemiology of Injury in Olympic Sports. Volume XVI of The Encyclopedia of Sports Medicine. Oxford: Wiley-Blackwell; 2009, 473-488.
Descriptive Epidemiology of Paralympic Sports Injuries Nick Webborn, MB, BS FSEM (UK), Carolyn Emery, PT, PhD Abstract: Paralympic sports have seen an exponential increase in participation since 16 patients took part in the first Stoke Mandeville Games on the opening day of the 1948 London Olympic Games. More than 4,000 athletes took part in the London 2012 Paralympic Games. Few sporting events have seen such rapid evolution. This rapid pace of change also has meant challenges for understanding the injury risks of participation, not only because of the variety of sports, impairment types, the evolution of adapted equipment but also because of the inclusion of additional impairment types and development of new sports over time. Early studies were limited in scope but patterns of injuries are slowly emerging within Winter and Summer Paralympic sports. The IPC’s London 2012 study is the largest to date with a prospective cohort study involving 49,910 athlete-days. The results identified large differences across sports and highlighted the need for longitudinal sport specific studies rather than solely games-time studies. This will require collaboration with international sports federations to examine injury patterns and risk factors for injury in this population to appropriately inform injury prevention strategies. Further studies will also need to address the impact of sporting participation, injury, and future health. PM R 2014;6:S18-S22
INTRODUCTION Paralympic sports have seen an exponential increase in participation since 16 patients took part in the first Stoke Mandeville Games on the opening day of the 1948 London Olympic Games. More than 4000 athletes took part in the London 2012 Paralympic Games to packed audiences and worldwide television coverage. Few sporting events have seen such a rapid evolution. This rapid pace of change also has meant challenges for understanding the injury risks of participation because of inclusion of additional impairment types and development of new sports. In 1960, the International Stoke Mandeville Games were held in Rome and since that time, the Games have been held in the country selected for the Olympic Games where possible, save for financial or political reasons. In 1976, in Toronto, the Games included visually impaired and amputee athletes for the first time, and the Games were known as the Olympiad for the Physically Disabled. In 1980, in Arnhem, athletes with physical disabilities not fitting into the historical disability groups (Les Autres; fr. “the others”) or with cerebral palsy also were included. The International Paralympic Committee (IPC) was founded in 1989, and since 1994 the management of the Paralympic Games has been administered byr the IPC. Although athletes with intellectual disabilities have participated in some Paralympic Games, they are not included in this review. The data for this review were primarily published articles and reports from a literature search of PubMed and SPORTDiscus; however, information from Congress proceedings and both published and unpublished articles known to the authors but not identified through these database sources also were evaluated. English-language articles were used primarily, but some German texts were incorporated where translation could be performed. Search terms involved permutations and combinations of Paralympic, injury, cerebral palsy, visually impaired, wheelchair, disability, and sport. A variety of methodologic limitations, which confound the interpretability of the findings, were evident in the literature, particularly in earlier studies. Factors included a lack of standard definitions for reportable injury and injury details, short study timeframes, PM&R
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1934-1482/14/$36.00 Printed in U.S.A.
N.W. The Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK. Address correspondence to: N.W.; e-mail: [email protected] Disclosure: nothing to disclose C.E. University of Calgary, Alberta, Canada Disclosure: nothing to disclose Submitted for publication January 31, 2014; accepted June 10, 2014.
ª 2014 by the American Academy of Physical Medicine and Rehabilitation Vol. 6, S18-S22, August 2014 http://dx.doi.org/10.1016/j.pmrj.2014.06.003
PM&R
poor or absent exposure data, use of self-report surveys that did not include a confirmed medical diagnosis, and small sample sizes. In addition, the unique grouping of sports by disability makes obtaining a clear picture of injury risk and risk factors in Paralympic sport complicated. For example, when investigating the risk of injury related to a particular sport, of the 27 Paralympic sports (22 summer [planned in year 2016] and 5 winter), some are participated in by athletes with different impairments (athletics: spinal cord injured, visually impaired, amputee, and cerebral palsy), some are unique to particular disability categories (goalball: visually impaired; wheelchair rugby: athletes with impairment in all 4 limbs), some are modified by rules (judo) or equipment (sit-ski; sledge hockey) for particular classes of athletes, and some involve multiple categories of disability on the same team (basketball). Caution also may be required intepreting studies if the investigation is focused on the risks related to a particular class of disability across different sports. For example, a lower limb amputee athlete may compete with a prosthesis for track athletics or cycling, without a prosthesis for swimming or high jump, or in a wheelchair for sports such as basketball and tennis. Athletes with cerebral palsy may be ambulant or wheelchair users depending upon the degree of disability. Some more recent studies have used a combination of impairment and sport specificity to limit these confounders but so far have relatively few athlete numbers, and the results need to be treated with some caution [1-3]. Changes in professionalism and level of participation in disability sport impose a further difficulty in interpreting the available data. In the 1970s and 1980s, it was not uncommon for individual athletes to participate in multiple sports, even at the Paralympic Games. In a survey of 128 athletes with disabilities, Curtis and Dillon [4] found 79% were competing in track athletics, 71% in wheelchair basketball, 57% in road racing, and 60% in field events in athletics. This occurrence would be rare in elite disability sports now. Technology in the form of lightweight, high tensilestrength materials and improved designs for wheelchairs and prostheses for different populations of Paralympic athletes have changed performance parameters and injury risk characteristics during the past 2 decades. In addition, training protocols and access to specialized trainers, coaches, and medical personnel have changed during the past few decades. As such, comparisons between injury patterns seen 20-30 years ago and those seen currently may not be appropriate. In addition, findings from older research articles in this area may not reflect the current position in elite Paralympic sport. Thus, a broad overview of injury patterns in Paralympic sports potentially loses sight of risk and risk factor relationships in specific sport/disability interactions, and the small numbers in any particular combination renders analyses and conclusions unstable. In an attempt to address some of these issues, the IPC’s Injury Surveillance System
Vol. 6, Iss. 8S, 2014
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(ISS) was implemented during the 2002 Salt Lake City Winter Paralympic Games and has continued at all subsequent Winter Paralympic Games. The first summer games injury and illness survey was during the London 2012 Paralympic games and was the first study to report on sport-specific injury incidence rates considering exposure to risk.
WHO IS AFFECTED BY INJURY? A comparison of injury rates (IRs) reported in prospective and retrospective research is summarized in Table 1 [5-17]. As noted previously, some studies involved multiple disability groups and some covered only individual disability groups; sports surveyed ranged from the full complement of summer Paralympic sports to individual sports. Few studies reported incidence rates because of the omission of exposure data. Interpretability of the results often is challenging in the absence of a reportable injury definition or by the variation of the definition between studies. Invariably, the definition will influence both the data collected and the risk assessment of the sports studied. For example, several retrospective questionnaire studies included minor soft-tissue injuries (eg, blisters or abrasions for which no medical attention was sought) whereas other research, which was based on the organizing committee’s medical services at Paralympic Games, did not include minor soft-tissue injuries.
Summer Sports The first study to attempt to quantify exposure data was a 2-year prospective study by Ferrara et al [8] of 319 multidisability athletes in summer Paralympic sports. An overall IR of 9.3 injuries/1000 participation hours was reported; however, no sport-specific details were provided, and self-reported symptoms have inherent limitations. The London 2012 injury survey13 captured data from 3565 athletes (84% compliance by athletes) from 160 delegations (98% compliance by delegation) during training and competition in the 20 summer sports. A total of 49,910 athlete-days were monitored during which a total of 633 injuries in 539 athletes were documented. The overall injury incidence rate was 12.7 injuries/1000 athlete days (95% confidence interval [95% CI] 11.7-13.7). The overall incidence proportion was 17.8 injuries/100 athletes (95% CI 16.5-19.0); however, there were marked variations by sport, with the greatest injury rates in Football 5-a-side (IR 22.4 injuries/1000 athlete-days), Goalball (IR 19.5 injuries/ 1000 athlete-days), Powerlifting (IR 19.3 injuries/1000 athlete-days), wheelchair fencing (IR 18.0 injuries/1000 athlete-days), and wheelchair rugby (IR 16.3 injuries/1000 athlete-days). Sports with the lowest IRs included sailing (IR 4.1 injuries/1000 athlete-days), rowing (IR 3.9 injuries/ 1000 athlete-days), and shooting (IR 2.2 injuries/1000 athlete-days).
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Table 1. Distribution of injury onset: acute vs chronic Author Summer sports Curtis and Dillon [4]*yzx Ferrara and Davis [5]* Burnham et al [6]*yzx{ Richter et al [7]z Ferrara et al [8]*yzx{ Taylor and Williams [9]* Reeser [10]yx Ferrara et al [11]*yzx{ Nyland et al [12]*yzx Magno e Silva et al [1]{ Magno e Silva et al [3]{ Magno e Silva et al [2]{ Willick et al [13]*yzx{ Mean Winter sports Ferrara et al [14]*yx Webborn et al [15]*yzx{ Webborn [16]*yzx{ Webborn et al [17]*yzx{
Sample
Injuries (Frequency)
M:F, %
Type of Sport
Acute, %
Chronic, %
1200 19 151 75 426 53 89 1360 304 13 40 28 3565
128 19 108 27 137 38 41 1037 254 35 77 41 633
79:21 53:47 NR NR NR 77:23 All male NR NR All Male 70:30 68:32 66:34
Wheelchair sports Wheelchair sports Summer Paralympic Summer Paralympic Summer Paralympic Wheelchair racing Standing volleyball Multisport Summer Paralympic Football 5-a-side Track and field athletics Swimming Summer Paralympic
40 65 49 73 46 41 60 77 67 80 18 20 68 54
60 35 51 27 54 59 40 23 33 20 82 80 32 46
68 194 134 88 190 112 132
68 24 12 3 23 12 5
118
40
Alpine skiing Alpine skiing Ice sledge hockey Nordic skiing Alpine skiing Ice sledge hockey Nordic skiing Alpine skiing Ice sledge hockey Nordic skiing Wheelchair curling
50 91 83 50 78 64 80 45 40 40 0 56
50 9 17 50 22 36 20 55 60 60 100 44
Mean
78:22 79:21
79:21
75:25
NR ¼ not reported. *Spinal cordrelated disability. y Amputee. z Cerebral palsy. x Les Autres. { Visually impaired.
A separate study [18] describing injuries in 91 Polish Paralympians in Beijing (2008) and 100 in London (2012) reported an incidence rate of 29.8/1000 athlete-days (95% CI 22.1-37.6) in Beijing and only 15/1000 athlete-days (95% CI 9.0-21.0) in London. Three studies examining injury in elite Brazilian visually impaired athletes recorded longitudinal data during the period 2004-2008 in 3 separate sports but sample size is small and limited to one nation [1,3]. Allen [19] reported an injury prevalence of 6.3% in a survey of sailors with multiple disability types in the International Foundation for Disabled Sailing World Championship (n ¼ 24 teams). McCormick and Reid [20] reported the prevalence of injury in basketball (30.9%), track athletics (30.6%), and road racing (12.1%) in a retrospective study of wheelchair athletes; however, blisters and abrasions formed approximately 50% of these injuries, many of which did not require formal medical treatment.
Winter Sports Studies examining winter sports also included variation between reports on single events, such as Alpine skiing
compared with all winter Paralympic sports. A multicenter study describing injuries occurring in recreational skiers with a disability reported an injury incidence rate of 2 injuries/ 1000 skier days [21]. Webborn [16] reported comparative injury data by sport from 2 winter Paralympic Games (2002 and 2006) and found similar rates at both Games in each sport; however, the ISS captured sport injuries in 24% of all athletes participating in the 2010 Vancouver Winter Paralympic Games [17]. The injury risk was significantly greater than during the 2002 (9.4%) and 2006 (8.4%) Winter Paralympic Games, which may reflect improved injury surveillance methodology and data capture but also highlights the high risk of acute injury in alpine skiing and ice sledge hockey in particular. There were a total of 120 injuries among the 505 athletes (incidence proportion 23.8%, 95% CI 20.1-27.7). In Alpine skiing, 22% of competitors presented with an injury compared with 13% and 12% of competitors in 2002 and 2006, respectively. Downhill racing was the most likely cause of injury, with 4 new acute injuries occurring for every 100 race events. For ice sledge hockey, 34% of competitors presented with injury compared with 14% and 11% of competitors in 2002 and 2006, respectively. Nordic skiing and
PM&R
wheelchair curling have significantly lower injury rates at 18.6% and 18%, respectively.
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WHEN DOES THE INJURY OCCUR? Injury Onset
WHERE DOES INJURY OCCUR? Anatomical Location In studies involving wheelchair athletes, the upper limb, particularly the shoulder, is the most common site of injury, with a prevalence for shoulder injury ranging from 19% [20] across multiple wheelchair sports to 72% in female wheelchair basketball players [22]. However, Webborn and Turner [23] noted in their report on 244 British athletes seen during a 4-week period, including the build-up to, and competition in, a summer Paralympic Games that although the shoulder was the most common site of pain in wheelchair athletes (30%), the cervical and thoracic spine (59% and 8%, respectively) were the actual sites of pathology (resulting in referred pain to the shoulder) compared with 33% of specific shoulder pathology. In the London 2012 study [13], the distribution of injury by body part also was greatest in the upper limb irrespective of impairment type (50.2% of all injuries), with shoulder injuries being most prominent (17.7% of all). The knee was the most common injured region of the lower limb (7.9% of all injuries). In elite disabled standing volleyball players (including athletes with upper limb and lower limb impairments including amputation), Reeser [10] identified the foot and ankle as the most common site of injury (21%), followed by the shoulder (18%), wrist and hand (18%), and the knee (14%). In this study, the distribution of injury locations was not related to the type of disability. In a 4-year study examining injury in Brazilian visually impaired (n ¼ 13) footballers (soccer players) [1], the greatest proportion of injuries reported were lower limb (80%), head (8.6%), spine (5.7%), and upper limb injuries (5.7%). Webborn et al [15] noted that lower limb fractures were frequent in spinal cord-injured ice sledge hockey athletes and in standing athletes in Alpine skiing in the 2002 Winter Games. However, in the 2006 and 2010 Winter Games, only one lower limb fracture occurred in ice sledge hockey over both the Games compared with the 4 fractures seen in 2002 before the introduction of the regulation change on protective equipment and sledge height [17]. Athletes in seated Alpine classes consistently had more upper limb injuries in all 3 Winter Paralympics studied. Injuries to the head and neck in ice sledge hockey and Alpine events also were common. IRs in wheelchair curling appear consistently low across the 2 Games (2006 and 2010) in which the sport has been included. There were no recorded injuries in 2006. In 2010 although 9 of 50 (18%) curlers sought medical attention for musculoskeletal complaints, none of these was acute injuries, and 5 of the 9 encounters were for pre-Games nonsport-related symptoms.
Table 1 also presents the percent distribution of acute and chronic injuries in disability sport. here is approximately a 55:45 ratio of acute to chronic injuries reported in the literature for most summer and winter Paralympic sports; however, there is marked variation by sport as one would expect with differences between contact and endurance sports for example. This finding also may reflect when the injury data were collected, with competition surveys reporting more acute injuries [10,12,24] and longitudinal surveys reporting more chronic injuries [4,8].
WHAT IS THE OUTCOME? Injury Type In Summer Paralympic sports, the authors of a previous review [25] reported strains (mean ¼ 25.4%; range: 4%60%) and sprains (mean ¼ 22.8%; range: 3.7%-48%) to be the most common injury types. However, this finding varies greatly between studies. The use of self-report data in the majority of the studies raises questions about the validity of injury classifications in these works. The studies by Burnham et al [6] and Webborn et al [15], in which physician or therapist diagnosis was the basis for classification, may be considered more accurate. Three longitudinal studies [1-3] in visually impaired athletes in swimming, football 5-a-side, and track and field athletics reported injuries during a 5-year period in one national team squad. Two of the studies describe “muscle spasms” as the most common injury type but without further explanation as to whether this definition indicates muscle cramp, fatigue-related, or neurally mediated spasm. Thus, it remains unclear of the true nature of the problem and its significance for injury prevention. In the Winter Sports, contusions, fractures, and concussion are more prevalent because of the impact potential and speed. For example, in Ice Sledge Hockey in 2002 fractures comprised 33% of injuries. After modifications in regulations on protective equipment and sledge height, fractures accounted for 7.5% of all sledge hockey injuries in 2010. Only one of these fractures involved the lower limb. In Nordic and Alpine Skiing, there were 4 head injuries in the 2010 Winter Games, 3 of which prevented further participation in competition.
CONCLUSION There is significant variability in injury definitions, research designs, data collection methodology, and analytic approaches in the literature examining injury in disabled athletes during the past 2 decades. The IPC has supported the development of injury surveillance tools to ensure methodological rigor in examining injuries in the Paralympic Games
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that will hopefully lead to evidence informed safety and prevention practices in future game. Patterns of injuries are slowly emerging within Winter and Summer Paralympic sports, which highlights the need for longitudinal studies rather than solely games-time studies through collaboration with international sports federations. To further examine injuries and risk factors for injury in this population to inform injury prevention strategies, the IPC plans to continue the ISS during future summer and winter Paralympic Games while encouraging and supporting longitudinal, sport-specific studies.
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EPIDEMIOLOGY OF PARALYMPIC SPORTS INJURIES
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