Telemark skiing injuries: characteristics and risk factors

Transcription

1 Wilderness and Environmental Medicine, 10, (1999) ORIGINAL RESEARCH Telemark skiing injuries: characteristics and risk factors CAROL S. FEDERIUK, MD, PhD, N. CLAY MANN, PhD, MS From the Department ofemergency Medicine, Oregon Health Sciences University, Portland, OR. Objective.-To detennine the types of injuries associated with telemark skiing and the effects of ability level, equipment, and terrain. Methods.-A survey was mailed to a sample of North American telemark skiers. Results.-Completed surveys were returned by 548 telemarkers (response rate = 74.5%). The mean age was 42.7 (±9.3) years, and 69% were male. A total of 439 injury events resulted in 494 body injuries, reported by 285 skiers (52%). Lower-extremity injuries (n = 231) were more frequent than upper-extremity injuries (n = 187). Knee injuries were most common with 128 cases, followed by 80 thumb, 66 shoulder, and 44 ankle injuries. Surgery was required in 39 cases. Skiers suffering thumb injuries with sequela lasting greater than 3 months were 10.1 times less likely to have sought medical attention than skiers with other long-term injuries (p < 0.001). Injuries occurred more often at lift-served ski areas (74.2%) than in the backcountry (25.8% [P < 0.001, OR = 2.09]). There was no association between boot type and overall knee or ankle injury, but risk of severe ankle injury was increased in leather boots compared to plastic (OR = 8.0, CI = 1.05, 60.59). Release bindings were used by 27.9% of all skiers but were in use in only 18.7% of injury events, suggesting that release plates have a protective effect against injury (OR = 0.59, p < 0.001). In 66 of 82 injuries (80.5%) sustained while using release bindings, the bindings did not release. Conclusions.-The knee, thumb, shoulder, and ankle are most frequently injured telemark skiing. Injuries are more likely to occur at lift-served areas than in the backcountry. Thumb injuries are often ignored and may result in long-term sequela. Ankle injuries appear more severe in leather boots. Release bindings appear protective against injury, but they often do not release. Key words: skiing injuries, telemark skiing Introduction Telernark skiing is a specialized form of skiing that allows skiers to access and ski the backcountry as well as lift-served areas. Telemarking, also known as free-heel or Nordic downhill skiing, combines elements of crosscountry and downhill skiing to enable the skier to walk uphill and descend difficult wilderness terrain. The hallmark of telemark skiing is the telemark turn, which was developed by Sondre Norheim in the mid-1800s in the Telemark region of Norway [1]. The turn is accomplished by bending the rear knee and allowing the downhill ski to slide ahead, resulting in an elegant arcing turn (Fig 1). Telemarking has enjoyed a resurgence in popularity, partly due to a desire on the part of skiers to escape lift lines and to ski in the wilderness. Although Direct correspondence to Department of Emergency Medicine UHN 53, Oregon Health Sciences University, 3181 SW Sam Jackson Park Rd, Portland, OR (Dr Federiuk). telemark skiing employs other techniques in addition to the telemark turn, the name has been retained to describe modern Nordic downhill skiing. Telemark skiers use a wide variety of equipment, and new equipment is continually being developed and marketed. Telemark skis have large sidecuts and alpine camber for easier edging and turning than traditional crosscountry skis. The design reflects the fact that, in addition to the telemark turn, alpine techniques can be used for downhill travel. Telemark boots are higher and stiffer than touring models and are available in leather, plastic, and combinations of both materials. Several types of ski bindings are in use, all of which leave the heel of the boot unattached to the ski to allow the skier to walk uphill and to perform the telemark turn. Cable bindings, which loop around the back of the boot, are supplanting the traditional three-pin bindings that clamp the toe of the boot to the ski. Release plates, which can be attached to the skis and adjusted to release the binding from the

2 234 Federiuk and Mann STUDY POPULATION The survey was mailed to a sample of telemark skiers between September and December The sample was obtained from lists of telemark skiers provided by two telemark ski instructors in the Pacific Northwest. One list consisted mainly of telemark skiers who had participated in or shown interest in telemark ski lessons. The other list was comprised primarily of skiers who had ordered a telemark ski videotape. An additional small sample of telemarkers was obtained at a telemark ski clinic. The survey envelopes were numerically coded to track response. Nonrespondents were mailed a reminder postcard approximately 3 weeks after the initial survey, and the survey was r ed 3 weeks later if there was still no response. A cover letter encouraged response regardless of whether or not the skier had ever sustained an injury while telemark skiing. Participation also was encouraged by including respondents in a raffle for a ski jacket donated by a local merchant. Returned surveys were separated from the envelopes and entry forms to maintain the confidentiality of the respondents. Fig 1. Telemark tum. Photo courtesy of Marty Scott. MEASUREMENTS ski if significant lateral force is encountered, have been available to telemarkers since the mid-1980s. Little is known of the injuries associated with telemark skiing. Two recent prospective studies of telemark ski injuries have been published [2,3]. These studies evaluated only the proportion of telemark skiers found at lift-served areas and thus, are limited in sample size and general application. To surmount these limitations, we conducted a large retrospective survey that included both lift-serve and backcountry telemark skiers. The purpose of this study was to define the types of injuries occurring during telemark skiing and to evaluate the effects of ability level, terrain, and equipment on injury type and severity. Methods STUDY DESIGN A two-page survey was administered to a convenience sample of telemark skiers with varying levels of experience and skill. The survey was reviewed and approved without informed consent by the Oregon Health Sciences University Institutional Review Board. The survey questions included demographic data, such as age, gender, experience level, and number of years skied. The type of ski equipment used and type of area skied were also included. Skiers were asked if they had ever been injured telemark skiing and, if so, to provide details regarding the three injuries that they considered most serious. Injury information included injury location, duration of the symptoms, whether medical care was sought, and whether surgery was required. Circumstances surrounding the injuries were also queried, including equipment used and mechanism of the injury. The survey was piloted on a sample of 14 telemark skiers attending a telemark ski clinic. Several survey questions were modified based on the skiers' responses and comments. Data were entered into an electronic database and analyzed using SPSS for Windows (Vers. 8.0). Bivariate relationships were assessed using standard statistical tests, including chi-square and independent sample ( tests. A Fisher's exact test was used for small samples. An odds ratio was used to measure the strength of association between categorical variables. Multivariate logistic regression models were constructed to assess differences among injured and noninjured skiers controlling for potentially confounding variables. A "forced entry" method was used to enter variables into the logistic mod-

3 Skiing injuries 235 Table 1. Characteristics of uninjured and injured skiers Variable Uninjured (n = 263) Injured (n = 285) Significance level Association Age 42.5 ::!:: ::!:: 8.9 N.S. Gender Male 166 (63.1%) 212 (74.4%) p = OR = 1.69 Female 97 (36.9%) 73 (25.6%) Experience level Beginner 50 (19.5%) 15 (5.3%) Comparison Intermediate 98 (38.3%) 72 (25.4%) p = OR = 2.45 Advanced 85 (33.2%) 116 (41.0%) p < OR = 4.55 Expert 23 (9.0%) 80 (28.3%) p < OR = Years skied Telemark 6.4 ::!:: ::!:: 5.7 p < Downhill 12.8 ::!:: ::!:: 12.4 N.S. Cross-country 11.7 ::!:: ::!:: 9.7 N.S. Days telemarked in season 14.7 ::!:: :±: 25.3 p < Boots Leather 148 (53.8%) 116 (37.2%) Comparison Plastic 97 (35.3%) 37 (43.9%) p =.002 OR = 1.65 Combination 30 (10.9%) 59 (18.9%) p =.018 OR = 2.23 Bindings Three-pin 81 (31.5%) 61 (21.6%) Comparison Toe bar 24 (9.3%) 14 (5.0%) p = OR = 0.77 Cable 152 (59.1%) 207 (73.4%) p = OR = 1.80 Release plate No 199 (75.7%) 196 (68.8%) N.S. Yes 64 (24.3%) 89 (31.2%) el. Associations were considered statistically significant at the 0.05 level. Results SURVEY RESPONSE Surveys were sent to 946 individuals, with 218 returned for invalid addresses. Of the 728 surveys sent to valid addresses, completed surveys were returned by 542 individuals for a response rate of 74.5%. Nine of these respondents were excluded from the study population because they indicated that they did not telemark ski. An additional 15 individuals completed the survey at a telemark ski clinic, resulting in a total of 548 respondents included in the study sample. DEMOGRAPHICS The age of the survey participants varied from 10 to 79, with a mean of 42.7 (:±:9.3) years. Sixty-nine percent of the telemarkers were male. The respondents were divided almost equally between those who had never been injured telemark skiing (48%) and those who had sustained one or more injuries (52%). Demographic data for the uninjured and injured groups are presented in the Table. There was no difference in age between the injured and uninjured groups. Based on bivariate comparisons, male skiers were more likely to have sustained injuries than female skiers (p = 0.004, OR = 1.69). However, after adjustment for experience level and age using a logistic model, there was no significant difference in risk of injury between males and females. Expert skiers, skiers with more years of telemark experience, and those who had telemarked a greater number of days in the past season were more likely to have sustained injury (p < 0.001). The proportion of telemarkers who had sustained injury steadily increased from the beginner through the expert level. Only 15 of 65 beginner skiers (23.1 %) had ever been injured, while 80 of 103 experts (77.7%) had sustained one or more injury.

4 236 Federiuk and Mann 140, , ~, ~ l?i Number of injuries!iii Medical Care Surgery Number of skiers Fig 2. Lower extremity injuries (N = 231). Hip Upper Leg Knee Lower Leg Ankle Foot INJURY CHARACTERISTICS A total of 439 injury events were reported by 285 skiers. One injury event was reported by 162 skiers, two by 73 skiers, and three by 39 skiers. Four or more injury events were reported by 11 skiers, but only the three most serious events were described due to space limitations on the questionnaire.. A total of 494 injuries to various body regions were associated with the 439 injury events. The distribution of injuries is shown in Fig 2-4. Lower-extremity injuries (n = 231) were more frequent than upper-extremity injuries (n = 187). Knee injuries (n = 128) were most common, comprising 25.9% of all injuries. Injuries to the thumb were second most common with 80 injuries (16.2%), followed by 66 shoulder injuries (13.4%) and 44 ankle injuries (8.9%). Next most frequent were head injuries with 26 (5.3%), 26 trunk injuries (5.3%), and 24 spine injuries (4.9%). Medical care was sought after 197 of the 439 injury events (44.9%). Skiers most frequently sought medical care for hand (66.7%) and wrist (61.5%) injuries (Fig 3) and least often for hip (16.7%) and upper leg (15.8%) injuries (Fig 2). Surgery was required in 39 cases, most commonly for knee (n = 18), shoulder (n = 7), and 120-, , Number ofskiers , Number of injuries rib Medical Care Surgery o Fig 3. Upper extremity injuries (N = 187).

5 Skiing injuries Number ofskiers Number ofinjuries DMedical Care Surgery Spine Trunk Head Fig 4. Other injuries (N = 76). thumb injuries (n = 5). Surgery was required twice each for ankle and hand injuries and once each for arm, hip, lower leg, wrist, and head injuries. Specific information regarding the type of knee injury was provided by 93 of the 128 skiers reporting a knee injury. Contusions or lacerations to the knee were sustained by 17 skiers, sprains by 39, and severe sprains, tom ligaments, or tom cartilage by 32 skiers. There were four patellar fractures and one femur fracture. A description of ankle injuries was provided by 33 of 44 skiers. One skier sustained an ankle contusion, 16 experienced sprains, 10 suffered severe sprains or tom ligaments, and 6 skiers had fractures. Other serious lower-extremity injuries included three tibia/fibula fractures. Head or facial lacerations accounted for 10 of the 26 head injuries. Two head injuries caused symptoms that lasted longer than 3 months, but the specific injuries were not described. There were 23 neck and back strains, 15 rib bruises or fractures, and 1 coccyx fracture. Descriptions of shoulder injuries included 7 dislocations, 10 strains, 11 rotator cuff injuries, 1 glenoid fracture, 2 clavicle fractures, and 1 unspecified fracture. Other upper-extremity injuries included two humerus fractures, five hand fractures, and three wrist fractures. Half of the skiers with thumb injuries described their injury. Thumb sprains or ulnar collateral ligament tears were reported by 38 skiers, and thumb fractures were reported by two skiers. Seventeen thumb injuries caused symptoms that lasted longer than 3 months, but medical care was sought for only three of these injuries (17.6%). In contrast, 61 of 89 skiers with other injuries lasting greater than 3 months (68.5%) sought medical attention. A comparison of skiers with prolonged symptoms following thumb injuries to skiers with symptoms lasting 3 or more months from all other injuries demonstrated that the skiers with thumb injuries were 10.1 times less likely to have sought medical care than skiers with all other types of long-term injuries (p < 0.001). INJURY MECHANISM Injury events occurred at lift-served ski areas in 293 cases (74.2%) and in the backcountry in 102 cases (25.8%), with no location specified for 44 events. Of all 548 survey respondents, 203 (37%) indicated that they skied primarily at lift-served areas, 148 (27%) skied primarily in the backcountry, 192 (35%) skied both areas equally, and 5 (1 %) did not respond to the question. A comparison of the number of injury events occurring at lift-served areas (n = 293) and in the backcountry (n = 102) vs the number of all skiers who skied primarily at lift-served areas (n = 203) and the backcountry (n = 148) was significant (p < 0.001), demonstrating a 2.1 times increased risk of injury at lift-served areas compared to the backcountry. This finding remained significant when the 44 events for which no location was specified were considered to have occurred in the backcountry. There was no difference in the type of ski area fa-

6 238 vored by inexperienced and experienced skiers. Thus, this result was not confounded by more advanced skiers favoring the lifts. Among skiers injured in the backcountry, there was a 66% excess of knee injuries compared to skiers injured at lift-served areas (p < 0.05, OR = 1.66). There was no difference in the risk of injury to other body regions comparing those primarily skiing backcountry or liftserved areas. Telemarkers injured in the backcountry were as likely as those injured at lift-served areas to seek medical attention (p = 0.57). Injuries were caused by a variety of mechanisms including catching an edge (n = 141), crossing ski tips (n = 68), and excessive speed (n = 67). Collisions with skiers or snowboarders accounted for 10 injuries at liftserved areas and one injury in the backcountry. Collisions with trees or falls in tree wells caused 13 injuries, and hitting hidden rocks or other objects caused 13 injuries. Two skiers were injured when their bindings broke or released unintentionally. An additional two skiers were injured due to avalanches. Injured skiers reported the type of tum they were performing when injured in 286 cases. Telemark turns comprised 90.2% (258) of the movements at the time of injury, followed by parallel turns 6.3% (18), snowplowing 2.4% (7), and sideslipping 1.1 % (3). There was no significant difference in the type of tum performed for injuries occurring at lift-served areas compared to those incurred in the backcountry. EQUIPMENT The number of uninjured and injured skiers using leather, plastic, and combination boots at the time of the survey is shown in the Table. Fourteen uninjured skiers and 28 injured skiers indicated that they wore leather or plastic boots at times and were aggregated into both the leather and plastic groups. Skiers who wore plastic (p = 0.002, OR = 1.65) or combination leather/plastic (p = 0.018, OR = 2.23) boots were more likely to suffer an injury than skiers using leather boots. However, these differences were not significant after adjustment for experience level and frequency of telemark skiing. The proportion of skiers who sustained knee injuries while wearing plastic vs leather boots was compared to the total injured population wearing each type of boot. There was no association between boot type and knee injury (p = 0.06). The proportion of skiers who sustained ankle injuries in plastic and leather boots was also compared to the total injured population using each type of boot. There was no increase in risk of ankle injury with leather boots (p = 0.18). After controlling for ex- Federiuk and Mann perience level and days of telemarking in the last season, this relationship was still insignificant. A comparison of injury severity and boot type, however, did demonstrate an increased risk of "severe" ankle injuries in leather boots compared to plastic (OR = 8.0, 95% CI = 1.05, 60.59). Of the 21 ankle injuries described that occurred in leather boots, there were 12 serious injuries (seven severe strains and five fractures). Of the seven ankle injuries described that occurred in plastic boots, there was only one severe strain and no fractures. A majority of skiers in both the uninjured and injured groups were using cable bindings at the time of the survey (the Table). Skiers with cable bindings were more likely to have been injured than those with three-pin bindings (p = 0.002). However, after controlling for experience level, this difference was also insignificant. Releasable bindings were used by 153 of 548 skiers (27.9%) but were used in only 82 of 439 (18.7%) injury events. Comparison of the proportion of skiers using release plates when injured to the total population using release plates when surveyed suggested that release bindings have a protective effect against injury (p < 0.001, OR = 0.59). There was no difference in mean number of years skied between injured skiers who used release bindings (8.7 years) and injured skiers who did not use release bindings (9.9 years). Therefore, the low proportion of injured skiers using release plates is not likely due to a lack of commercial availability of release bindings at the time of injury. In 66 of 82 injuries sustained while using a release plate (80.5%), the bindings did not release. Discussion The current literature related to telemark ski injuries is limited to two prospective studies [2,3] and one retrospective report [4]. A few ski injury reports over 20 years ago included data on mountain touring skiing, which was sometimes referred to as cross-country skiing [5,6]. Over two-thirds of the study population was male, consistent with a predominance of male telemarkers in previous studies [2,3]. The average age of 42 years is older than in the prospective studies of telemarkers [2,3] and injured alpine skiers [7,8] but is similar to retrospective data for te1emark skiers [4]. Knee injuries were the most common injury (25.9%), followed by thumb (16.2%), shoulder (13.4%), and ankle injuries (8.9%). This injury distribution differs somewhat from previous studies of telemark injuries. The Swedish study of telemark skiers reported thumb injuries (32%) as most common, followed by knee injuries

7 Skiing injuries (25%) [3]. Other studies reported ankle injuries [2] or knee injuries [4] as most common. Head and face injuries were somewhat less common in this study (5.3%) than in previous studies of telemarkers (10%-21 %) [2,3]. These differences may be related to any number of factors including small sample sizes, differences in ski equipment or skier experience levels, or different study populations in this retrospective survey vs prospective surveys of patients seeking medical care at ski areas. The injury distribution of this telemark study bears some resemblance to both that found in alpine skiing and that of cross-country skiing. Knee injuries are the most common alpine skiing injury (25%-35%), followed by head and face injuries (9%-16%), shoulder (8%-12%), and thumb (4%-8%) injuries [7-12]. In cross-country skiers, knee injuries are most frequent (25%), followed by ankle and foot injuries (15%-18%), shoulder and head (9%-11 % each), and thumb injuries (8%) [10,13,14]. The proportion of ankle injuries in our study is closer to the proportion found in downhill skiing (4%-7%) [7-10] than that found in cross-country skiing. However, the high proportion of upper-extremity injuries (37.8%) in our study more closely resembles that found in cross-country skiing (approximately 35%) [10,13] than in downhill skiing (19%-30%) [7-11]. It is not unexpected that the injury pattern seen in telemark skiing shares similarities with the patterns seen in both cross-country and alpine skiing. Telemark skiing is similar to cross-country skiing in that the heels are not attached to the skis, and the diagonal stride technique can be used for forward momentum. In addition, the majority of telemarkers do not use releasable bindings. Like alpine skiers, telemark skiers use metal-edged skis with large sidecuts and single camber and can use alpine parallel tum techniques to attain high speed on downhill runs. Telemark boots may be made of hard plastic, resembling downhill boots, or softer leather. The telemark tum, which was being used in 90% of injury events in this study, is a unique function of telemark skiing. Thus, telemark skiing injury patterns may represent a combination of patterns seen in alpine and nordic skiing but also may be expected to have unique properties. The cumulative risk of injury was associated with time spent telemark skiing as measured by experience level, years of telemark skiing, and days skied per season. Age and gender were not significant factors in injury risk. Medical care was sought only after 45% of the injury events. Thus, a majority of telemark injuries may not be reported if information is gathered by traditional methods, such as from ski area medical clinic records or even from ski patrol reports. Skiers with chronic thumb in- 239 juries were 10 times less likely to seek care for the problem than those with other chronic injuries, probably because they felt a thumb injury was minor. There was an increased risk of injury at lift-served compared to backcountry ski areas. Skiers who favored the lifts and those who skied primarily in the backcountry had skied approximately the same number of days in the past season. The increased risk at lift-served areas is likely due to the greater vertical distances skied per day at the lifts. The vertical decline from ski lifts may be more representative of risk exposure than days skied and has been used in Switzerland to calculate injury rates in downhill skiing [15]. Alpine ski injury patterns have changed over the years with modifications to equipment. Ankle injuries were more common than knee injuries in alpine skiing during the 1960s [5,16]. A steady decrease in ankle injuries in alpine skiing over the years has been attributed to the introduction of higher and stiffer boots and to improvements in the release function of boots and bindings [16 18]. Alpine knee injuries have decreased only slightly or increased, possibly due to transfer of energy higher up the leg by protecting the lower leg in a stiff plastic boot [8,12,18]. This study found no increased risk of overall ankle injury for telemarkers in leather boots compared to plastic; however, ankle injuries were more severe in leather boots. The trend for increased risk of knee injuries in leather boots compared to plastic also did not reach statistical significance. Variation in boot styles and stiffness within leather and plastic boots as well as differences in binding types may playa role in these results. In addition, the injury mechanism may be different in telemark skiing, since the heel is not fixed to the ski, as in a downhill boot. Most telemarkers were performing a telemark tum when injured, and this position is never used in downhill skiing. This analysis used the total injured population as a reference population, since there is no way to determine the relative proportions of skiers who used leather and plastic boots over the course of the study. Among those using release bindings, the bindings did not release in >80% of injuries in this study. The release plates commercially available to telemarkers during the course of this study were not Deutsches Institut fur Normung (DIN) or International Standards Organisation certified. Settings are individually determined by the skier, and most telemarkers set the binding release tension based on trial and error. It is not known whether the poor release rate is due to release binding design or overly tight settings. The low rate of binding release in this study is reminiscent of data regarding downhill binding release in

8 240 Federiuk and Mann the 1960s. In one Swiss study of alpine skiing injuries, 86% of safety bindings did not release on the side of the injured leg in injuries occurring in 1967, and 64% did not release in 1972 [15]. Most release settings were set above recommended values, and a majority of skiers had not had their bindings adjusted during the ski season. In a 1993 study, 52% of alpine bindings did not release [17]. In that study, bindings that had been tested prior to the accident were more likely to release than bindings that had not been tested. Improper binding settings and the nonrelease of bindings have been shown to increase the risk of' lower-extremity injuries in alpine skiing [6,7,19-21]. Our study suggests that release bindings decrease the risk of injury in te1emark skiing; however, current bindings often do not release during an injury event. It is possible that industry standards for bindings and adjustments performed by professionals may decrease the incidence of telemark ski injuries. New teleniark release bindings, which are DIN certified and require professional adjustment, have been introduced commercially in the past year. Further study will be needed to determine if these and other new bindings reduce the risk of lower-extremity injuries in telemark skiing. STUDY LIMITATIONS The retrospective design of this study could have resulted in a selection bias in the sample. The sample population consisted of motivated telemark skiers who demonstrated interest in lessons or videotapes. It is unknown if this population is representative of all telemark skiers. The bias was reduced by multiple mailings that resulted in a high overall response rate. The self-reporting of injuries limited the completeness and accuracy of diag-. noses. However, this method resulted in disclosure of many injuries (55%), for which medical attention was never sought. Since this was a retrospective study, no attempt was made to calculate injury rates per skier day. The small sample size of skiers with release bindings precluded determination of the relative risk of injury to specific body areas when bindings fail to release. In addition, the retrospective design of this study may have missed some telemark skiers who sustained injuries severe enough to preclude them from further skiing and thus, were no longer included on the telemark skier mailing lists. Such severe injuries are probably uncommon, since the years of telemark skiing experience were greater in the injured population than in the uninjured population, suggesting that telemarkers are able to continue to ski despite injuries. Summary Telemark skiing is a unique form of skiing, which presents a distinctive pattern of injuries. Knee injuries are most common followed by thumb, shoulder, and ankle injuries. The risk of injury is related to increased time and experience telemark skiing. Injuries are more likely to occur at lift-served areas than in the backcountry. Ankle injuries appear to be more severe in leather boots. Releasable bindings appear protective against injury, but they often do not release. Further study is needed to investigate the effect of release bindings on telemark ski injuries. Acknowledgments The authors thank Shelley Butler and Nils Larsen for the use of their mailing lists, Don Pattison of Solstice for donation of the ski jackets, and Terri Davis for graphics support. Presented at the World Congress on Wilderness Medicine, Whistler, British Columbia, Canada, August 1999, and the 13th International Symposium on Ski Trauma and Skiing Safety, Breuil Cervinia, Italy, May References 1. Parker P. Free Heel Skiing. 2nd ed. Seattle, WA: The Mountaineers; Federiuk CS, Zechnich AD, Vargyas GA. Telemark skiing injuries: A three-year study. Wilderness Environ Med. 1997;8: Jorgsholm P, Bauer M, Ljung BO, Lerner A. Downhill skiing is developing-snowboard and telemark skiing give new injury patterns. Lakartidningen. 1991;88: Tuggy ML. Telemark skiing injuries. J Sports Med Phys Fitness. 1996;36: Westlin NE. Injuries in long distance, cross country, and downhill skiing. Orthop Clin North Am. 1976;7: Eriksson E. Ski injuries in Sweden: A one year survey. Orthop Clin North Am. 1976;7: Bouter LM, Knipschild PG, Volovics A. Binding function in relation to injury risk in downhill skiing. Am J Sports Med. 1989;17: Davidson TM, Laliotis AT. Alpine skiing injuries. A nine year study. West J Med. 1996;164: Warme WJ, Feagin JA, King P, Lambert KL, Cunningham RR. Ski injury statistics, 1982 to 1993, Jackson Hole Ski Resort. Am J Sports Med. 1995;23: Sherry E, Asquith J. Nordic (cross-country) skiing injuries in Australia. Med J Aust. 1987;146: Kocher MS, Feagin JA. Shoulder injuries during alpine skiing. Am J Sports Med. 1996;24: Johnson RI, Ettlinger CF, Shealy IE. Skier injury trends. In: Skiing Trauma and Safety: Seventh International Sym-

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