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Snowboarding injuries: Comparison of injuries in snowboarders and skiers
~
J Orthop Sci (1996) 1:178-181
lournalof
thopaedic Science The Japanese Orthopaedic Association
Snowboarding injuries: Comparison of injuries in snowboarders and skiers TETSUYA TAKAKUWA a n d SHIGEATSU ENDO Critical Care and Emergency Center, Iwate Medical University, 19-1 Uchimaru, Morioka 020, Japan
Abstract: To clarify the characteristics of injuries occurring in snowboarding accidents, we compared injuries in 138 snowboarders and 128 skiers (aged 15-35 years), injured at the "H" Ski Resort. In the snowboarder group, injuries to the upper extremities, particularly the wrist joint, were more frequent, whereas injuries to the lower extremities, particularly the knee joint, were less frequent. As for the type of injury, fractures were more frequent in snowboarders, while sprains and ligament injuries were less frequent. Fractures, sprains of the wrist joint, and contusions of the shoulder were more frequent in snowboarders, with sprains of the knee joint and the thumb were being less frequent. The duration of sporting activity was significantly longer in snowboarders. Injuries to snowboarders occurred more often while they were traveling at "reckless speed" on moderate slopes. There were no significant differences in skill levels between the two groups. Differences between the snow boarders' and skiers' boots and differences in sliding on boards and on skis are believed to have contributed to the differences in their injuries. Our analysis indicates that it is necessary to create slopes that are safe and enjoyable for board riders as well as skiers. Lessons are also recommended so that snowboarders learn the proper technique, and understand the general principles of slope safety; the potential for injury would thus be reduced. Key words: sports injury, snowboarding injury, skiing injury, epidemiology
Introduction The population of snowboarders has been increasing rapidly in the past few years, with young people accounting for much of the growth. As estimated by the Japanese Snowboarding Association from the number
Offprint requests to: T. Takakuwa Received for publication on Aug. 30, 1995; accepted on Dec. 18, 1995
of snowboards sold on the market, the population was 60000 in fiscal year 1988, and 300000 in 1992, showing an approximately five-fold increase over this 5-year period. We compared snowboarding injuries and skiing injuries treated at the first-aid station of " H " Ski Resort (located in Iwate Prefecture, Japan) and determined their distinctive features. Since snowboarders and skiers use the same slopes, the snowboarding and skiing injuries analyzed in this study would appear to reflect the characteristic features of the two types of sport.
Subjects and methods Between 1991 and 1993, 140 snowboarding and 282 skiing injuries were treated at the first-aid station of " H " Ski Resort. The patients with snowboarding injuries were predominantly young people in their 20s, while those with skiing injuries included a large proportion of children. Since the features of skiing injuries in children differ from those in adults) we limited our study to patients between 15 and 35 years of age. Information on all patients brought to the first-aid station was recorded by one of the staff on a data base sheet and included the following: name, age, sex, mode of sustaining injuries, date and time at which injury was sustained, duration of sporting activity, skill level, speed at which injury was sustained, and the gradient, the weather, and the condition of the surface of the slope. The anatomic site and the type of injury were also recorded. If the final diagnosis was not made at the first-aid station, we obtained it at a later date from the patient or from the hospital to which the patient was referred. The patients were divided into three skill levels: beginners, who had little experience at snowboarding and could not easily negotiate a slope; middle-level, those who could negotiate a slope; and advanced, those snowboarders who had 3 years' or more experience and could negotiate a medium or steep slope. The speeds at
T. Takakuwa and S. Endo: Snowboarding injuries which injuries were sustained were divided into four groups: "safe speed," i.e., controllable speed; "reckless speed," i.e., uncontrollable speed; low speed, a speed at which the snowboarder could immediately stop; and "stopped", i.e., a complete stop. The gradients of the slopes were classified into two classes; gentle slope (0 - 9 degrees), and medium slope ( 1 0 - 1 9 degrees). Surface conditions were evaluated by the staff and classified as of three types: smooth, irregular, and deep snow-covered. Weather at the time the injury was sustained was evaluated by the staff and classified as: fair, cloudy, snowing, or "other." Comparison was made with data on skiing injuries for the same period. The significance of differences in the anatomic site and type of injury was analyzed by a twodimensional table and a test based on the z statistic at a significance level of P < 0.05. The speeds at which injuries were sustained were analyzed by Fisher's exact probability test. Other conditions were analyzed by the X2 test.
Results
During the period examined there were 138 snowboarding injuries and 128 skiing injuries in subjects who were 15-35 years of age.
Anatomic site and type of injury In the snowboarding group, we found a higher incidence of injury to the upper half of the body than to the lower half. The incidence of snowboarding injuries to the lower limbs was higher on the left side (n = 23) than on the right side (n = 13). As for the type of injury, fractures were the most frequent (n = 36, 26.1%), followed by sprains (n = 35, 25.6%), contusions (n = 26, 18.8%), lacerations (n = 24, 17.4%), dislocations (n = 16, 13.0%), and other (n = 1). Compared with skiing injuries, snowboarding injuries to the upper half of the body were significantly more frequent and injuries to the lower half of body were less frequent (P < 0.01; Table 1). In particular, injuries to the wrist were significantly more frequent, and injuries to the knee joint were significantly less frequent in snowboarding than in skiing injuries (P < 0.001 for both). Injuries to the ankle joint were more frequent among snowboarders, but not significantly so. Fractures were significantly more frequent in snowboarders (26.1% vs 7.0%; P < 0.001), while sprains and ligament injuries were significantly less frequent (25.6% vs 53.9%; P < 0.001) among snowboarders than among skiers. In particular, wrist fractures (P < 0.001), sprains (P = 0.033), and shoulder contusions (P = 0.038) were significantly more frequent in snowboarders (Table 2).
179 Table 1. Comparison of snowboarding and skiing injuries - anatomic distribution Anatomic site Total no. of subjects Head and neck Central body Upper limbs* Wrist* Shoulder Elbow Hand Upper arm Lower limbs* Knee* Lower leg Ankle Other Upper/lower half of body*
Snowboarding n (%)
Skiing n (%)
138 28 (20.3) 11 (8.0) 63 (45.7) 25 (18.1) 23 (16.7) 9 (6.5) 3 (2.2) 3 (2.2) 36 (26.1) 13 (9.4) 5 (3.6) 17 (12.3) 1 (2.2) 2.83
128 27 (21.1) 7 (5.5) 25 (19.5) 2 (1.6) 13 (10.2) 2 (1.6) 8 (6.3) 0 (0.0) 69 (53.9) 51 (39.8) 6 (4.7) 12 (9.4) 0 (0.0) 0.86
*P < 0.01. Table 2. Comparison of type of injuries in snowboarding and skiing Injury Total no. of subjects Lacerations of the head Wrist fracture** Shoulder contusions* Knee sprain** Wrist sprain* Ankle sprain Ankle and/or lower leg fracture Torso contusions Skier's thumb*
Snowboarding n (%)
Skiing n (%)
138 23 (16.7) 16 (11.6) 16 (11.6) 12 (8.7) 9 (6.5) 9 (6.5) 9 (6.5)
128 17 (13.3) 1 (0.8) 5 (3.9) 49 (38.3) 1 (0.8) 12 (9.4) 3 (2.3)
9 (6.5) 0 (0.0)
4 (3.1) 6 (4.7)
*P < 0.05; **P < 0.01. Knee joint sprains (P = 0.001) and thumb sprains (P = 0.031) wer e significantly less frequent in snowboarders. Ankle joint and/or lower leg fractures, lacerations of the head, and contusions on the torso were more frequent in snowboarders, but not significantly so.
Mode of sustaining injuries and related factors A self-inflicted fall was the most frequent mode of sustaining snowboarding injuries (n = 109, 79.0%), followed by collision with another person (n = 20, 14.4%), collision with an obstacle (n = 6, 4.3%), and other (n = 3, 2.3%). T h e r e was no significant difference between the two groups in mode of injury. In the snowboarding group, injuries occurred more often while the subject was traveling at a reckless speed than at a low speed (Table 3; P < 0.001). Snowboarding injuries occurred significantly more frequently on a medium slope than did skiing injuries (Table 4; P =
180
T. Takakuwa and S. Endo: Snowboarding injuries
Table 3. Speed Speed Total no. of subjects Reckless Safe Low Stopped Unknown
Snowboarding n (%)
Skiing n (%)
138 18 (13.4) 78 (56.5) 25 (18.1) 5 (3.6) 12 (8.7)
128 6 (4.7) 49 (38.3) 52 (40.6) 4 (3.1) 17 (13.3)
Table 4. Gradient
Discussion
Gradient Total no. of subjects Medium Gentle Unknown
Snowboarding n (%)
Skiing n (%)
138 95 (68.9) 28 (20.3) 15 (10.9)
128 77 (60.2) 49 (38.3) 2 (1.6)
40" No. of injuries
I
20
O'
II
r
<1
differences between snowboarding and skiing injuries with respect to the surface of the slope or weather conditions. Injuries to both groups occurred most frequently in early January (the peak holiday snow season). The peak time of day was between 11 and 14:00h, and the highest incidence was on Saturdays and Sundays (the days on which the greatest number of people participate in these sports).
m 1
<2
<3
1
|
<4
_! 4<
duration of sports activity (hrs) Fig.1. Duration of sports activity on the day injury was sustained. Open columns, Snowboarding injuries; dark columns, skiing injuries 0.006). The duration of sporting activity was significantly longer in subjects who sustained snowboarding injuries than in those who sustained skiing injuries (Fig. 1; P = 0.01). The distribution of skill level in the snowboarding injury group was: beginners, n = 92 (66.7%), middle level, n = 25 (18.1%), and advanced, n = 7 (5.1%). The number of injuries in subjects at each skill level did not differ between snowboarding and skiing. The surface condition had been "smooth" and the weather "fair" at the time more than half of all patients had sustained the injuries. There were no significant
In snowboarders, we found a higher incidence of injuries to the upper half of the body than to the lower half, as previously reported in Japan. 7 Reports from countries other than Japan have indicated an equal incidence of injuries to the upper and lower halves of the body. 1,2,5 We believe the reasons for this discrepancy are (1) Resort, because, at ski slopes in Japan, the slope is smooth and well packed (as it is at the "H"), when the subjects: fall, their boards are seldom caught on the slope and their legs are seldom twisted. (2) Protective movements of the legs at the time of the fall are restricted, since the rider's feet are fixed to the board with bindings. This results in the hard impact being directly transmitted to various points on the upper half of body. (3) Injuries often occurred as the rider fell after trying to do a "trick jump" on the slope. 4 In this situation, snowboarders fall forward or backward, and place their hands on the slope for protection. (4) Collision (18.7% of cases); collisions usually involve the upper half of the body, as demonstrated in previous studies of skiing injuries. 6 Collision injuries in snowboarding may also cause injuries to the upper half of the body. Injury to the knee joint was less frequent in snowboarders than skiers, and the frequency of injury to the ankle joint and/or lower leg was the same for snowboarders and skiers. We have previously reported that these injuries could be caused by the external rotation of the lower limb, with the board acting as a lever arm, and that soft boots, which cannot fix the ankle joint, could contribute to these fractures. 4 At present, snowboarding footwear falls into two categories: soft and hard boots. In Japan, 73.4% of riders choose the soft boots, while the hard boots are used mainly by competitive or expert riders. 7 As the anatomic site of skiing injuries has been shown to change from the ankle joint to the knee, depending on the type of boot, it is possible that improvements in snowboarding equipment may also change the site of injury. ~,5 Since it is more difficult to shift the center of balance and to edge on a snowboard than on skis, snowbarding is probably not suited for quick turns or sliding at high speed; indeed, the incidence of injuries due to
T. Takakuwa and S. Endo: Snowboarding injuries u n c o n t r o l l a b l e m o t i o n on a m e d i u m slope was higher for s n o w b o a r d i n g than for skiing. S n o w b o a r d i n g has advantages over skiing in that it allows sliding on soft snow or deep, wet, and h e a v y snow, this being b e c a u s e the s n o w b o a r d has a large area of c o n t a c t with the surface of the slope. H o w e v e r , since almost all ski slopes in J a p a n are p r e p a r e d for skiing only, i.e., the surface is s m o o t h and well-packed, these conditions m a y m a k e it t o o difficult for s n o w b o a r d e r s to c o n t r o l their boards. It is necessary in future to create slopes that are safe and enjoyable for s n o w b o a r d riders as well as skiers. In the present study, of s n o w b o a r d e r s and skiers who were using the same slope, there was n o difference bet w e e n the groups in injuries sustained with respect to the time of day, day of the week, surface conditions, or weather. F u r t h e r m o r e , the slope was gentle, with an average gradient of less than 20 degrees, so that injuries for b o t h groups were similar at each skill level. In previous studies, 1,2,5,7s n o w b o a r d i n g injuries w e r e r e p o r t e d to be m o r e c o m m o n in beginners t h a n in those with experience. This p r o b a b l y reflects the fact that m o s t riders are lacking in experience and have yet to learn the relevant techniques. It is r e c o m m e n d e d that
181 s n o w b o a r d e r s take lessons to learn the p r o p e r technique and the general principles of slope safety; the potential for injury would thus be reducied.
References 1. Abu-Laban RB. Snowboarding injuries; an analysis and comparison with alpine skiing injuries. Can Med Assoc J 1991;145:1097103. 2. Bladin C, Giddings P, Robinson M. Australian snowboard injury data base study - - a 4-year prospective study. Am J Sports Med 1993;21:701-4. 3. Blitzer CM, Johnson RJ, Ettlinger CF, et al. Downhill skiing injuries in children. Am J Sports Med 1984;12:142-7. 4. Ohuchi S, Takakuwa T, Endo S, et al. Fractures caused by snowboarding (in Japanese). Rinsho Sports Igaku 1995;12: 1295-300. 5. Pino EC, Colville MR. Snowboard injuries. Am J Sports Med 1989;17:778-81. 6. Takakuwa T, Yasui Y, Endo S, et al. Skiing injuries caused by collisions (in Japanese). Rinsho Sports Igaku 1994;11:14227. 7. Takakuwa T, Ohuchi S, Endo S, et al. Injury and epidemiology of snowboarding (in Japanese). Seikeigeka (Orthop Surg) 1994;45:1697-701.
J Orthop Sci (1996) 1:178-181
lournalof
thopaedic Science The Japanese Orthopaedic Association
Snowboarding injuries: Comparison of injuries in snowboarders and skiers TETSUYA TAKAKUWA a n d SHIGEATSU ENDO Critical Care and Emergency Center, Iwate Medical University, 19-1 Uchimaru, Morioka 020, Japan
Abstract: To clarify the characteristics of injuries occurring in snowboarding accidents, we compared injuries in 138 snowboarders and 128 skiers (aged 15-35 years), injured at the "H" Ski Resort. In the snowboarder group, injuries to the upper extremities, particularly the wrist joint, were more frequent, whereas injuries to the lower extremities, particularly the knee joint, were less frequent. As for the type of injury, fractures were more frequent in snowboarders, while sprains and ligament injuries were less frequent. Fractures, sprains of the wrist joint, and contusions of the shoulder were more frequent in snowboarders, with sprains of the knee joint and the thumb were being less frequent. The duration of sporting activity was significantly longer in snowboarders. Injuries to snowboarders occurred more often while they were traveling at "reckless speed" on moderate slopes. There were no significant differences in skill levels between the two groups. Differences between the snow boarders' and skiers' boots and differences in sliding on boards and on skis are believed to have contributed to the differences in their injuries. Our analysis indicates that it is necessary to create slopes that are safe and enjoyable for board riders as well as skiers. Lessons are also recommended so that snowboarders learn the proper technique, and understand the general principles of slope safety; the potential for injury would thus be reduced. Key words: sports injury, snowboarding injury, skiing injury, epidemiology
Introduction The population of snowboarders has been increasing rapidly in the past few years, with young people accounting for much of the growth. As estimated by the Japanese Snowboarding Association from the number
Offprint requests to: T. Takakuwa Received for publication on Aug. 30, 1995; accepted on Dec. 18, 1995
of snowboards sold on the market, the population was 60000 in fiscal year 1988, and 300000 in 1992, showing an approximately five-fold increase over this 5-year period. We compared snowboarding injuries and skiing injuries treated at the first-aid station of " H " Ski Resort (located in Iwate Prefecture, Japan) and determined their distinctive features. Since snowboarders and skiers use the same slopes, the snowboarding and skiing injuries analyzed in this study would appear to reflect the characteristic features of the two types of sport.
Subjects and methods Between 1991 and 1993, 140 snowboarding and 282 skiing injuries were treated at the first-aid station of " H " Ski Resort. The patients with snowboarding injuries were predominantly young people in their 20s, while those with skiing injuries included a large proportion of children. Since the features of skiing injuries in children differ from those in adults) we limited our study to patients between 15 and 35 years of age. Information on all patients brought to the first-aid station was recorded by one of the staff on a data base sheet and included the following: name, age, sex, mode of sustaining injuries, date and time at which injury was sustained, duration of sporting activity, skill level, speed at which injury was sustained, and the gradient, the weather, and the condition of the surface of the slope. The anatomic site and the type of injury were also recorded. If the final diagnosis was not made at the first-aid station, we obtained it at a later date from the patient or from the hospital to which the patient was referred. The patients were divided into three skill levels: beginners, who had little experience at snowboarding and could not easily negotiate a slope; middle-level, those who could negotiate a slope; and advanced, those snowboarders who had 3 years' or more experience and could negotiate a medium or steep slope. The speeds at
T. Takakuwa and S. Endo: Snowboarding injuries which injuries were sustained were divided into four groups: "safe speed," i.e., controllable speed; "reckless speed," i.e., uncontrollable speed; low speed, a speed at which the snowboarder could immediately stop; and "stopped", i.e., a complete stop. The gradients of the slopes were classified into two classes; gentle slope (0 - 9 degrees), and medium slope ( 1 0 - 1 9 degrees). Surface conditions were evaluated by the staff and classified as of three types: smooth, irregular, and deep snow-covered. Weather at the time the injury was sustained was evaluated by the staff and classified as: fair, cloudy, snowing, or "other." Comparison was made with data on skiing injuries for the same period. The significance of differences in the anatomic site and type of injury was analyzed by a twodimensional table and a test based on the z statistic at a significance level of P < 0.05. The speeds at which injuries were sustained were analyzed by Fisher's exact probability test. Other conditions were analyzed by the X2 test.
Results
During the period examined there were 138 snowboarding injuries and 128 skiing injuries in subjects who were 15-35 years of age.
Anatomic site and type of injury In the snowboarding group, we found a higher incidence of injury to the upper half of the body than to the lower half. The incidence of snowboarding injuries to the lower limbs was higher on the left side (n = 23) than on the right side (n = 13). As for the type of injury, fractures were the most frequent (n = 36, 26.1%), followed by sprains (n = 35, 25.6%), contusions (n = 26, 18.8%), lacerations (n = 24, 17.4%), dislocations (n = 16, 13.0%), and other (n = 1). Compared with skiing injuries, snowboarding injuries to the upper half of the body were significantly more frequent and injuries to the lower half of body were less frequent (P < 0.01; Table 1). In particular, injuries to the wrist were significantly more frequent, and injuries to the knee joint were significantly less frequent in snowboarding than in skiing injuries (P < 0.001 for both). Injuries to the ankle joint were more frequent among snowboarders, but not significantly so. Fractures were significantly more frequent in snowboarders (26.1% vs 7.0%; P < 0.001), while sprains and ligament injuries were significantly less frequent (25.6% vs 53.9%; P < 0.001) among snowboarders than among skiers. In particular, wrist fractures (P < 0.001), sprains (P = 0.033), and shoulder contusions (P = 0.038) were significantly more frequent in snowboarders (Table 2).
179 Table 1. Comparison of snowboarding and skiing injuries - anatomic distribution Anatomic site Total no. of subjects Head and neck Central body Upper limbs* Wrist* Shoulder Elbow Hand Upper arm Lower limbs* Knee* Lower leg Ankle Other Upper/lower half of body*
Snowboarding n (%)
Skiing n (%)
138 28 (20.3) 11 (8.0) 63 (45.7) 25 (18.1) 23 (16.7) 9 (6.5) 3 (2.2) 3 (2.2) 36 (26.1) 13 (9.4) 5 (3.6) 17 (12.3) 1 (2.2) 2.83
128 27 (21.1) 7 (5.5) 25 (19.5) 2 (1.6) 13 (10.2) 2 (1.6) 8 (6.3) 0 (0.0) 69 (53.9) 51 (39.8) 6 (4.7) 12 (9.4) 0 (0.0) 0.86
*P < 0.01. Table 2. Comparison of type of injuries in snowboarding and skiing Injury Total no. of subjects Lacerations of the head Wrist fracture** Shoulder contusions* Knee sprain** Wrist sprain* Ankle sprain Ankle and/or lower leg fracture Torso contusions Skier's thumb*
Snowboarding n (%)
Skiing n (%)
138 23 (16.7) 16 (11.6) 16 (11.6) 12 (8.7) 9 (6.5) 9 (6.5) 9 (6.5)
128 17 (13.3) 1 (0.8) 5 (3.9) 49 (38.3) 1 (0.8) 12 (9.4) 3 (2.3)
9 (6.5) 0 (0.0)
4 (3.1) 6 (4.7)
*P < 0.05; **P < 0.01. Knee joint sprains (P = 0.001) and thumb sprains (P = 0.031) wer e significantly less frequent in snowboarders. Ankle joint and/or lower leg fractures, lacerations of the head, and contusions on the torso were more frequent in snowboarders, but not significantly so.
Mode of sustaining injuries and related factors A self-inflicted fall was the most frequent mode of sustaining snowboarding injuries (n = 109, 79.0%), followed by collision with another person (n = 20, 14.4%), collision with an obstacle (n = 6, 4.3%), and other (n = 3, 2.3%). T h e r e was no significant difference between the two groups in mode of injury. In the snowboarding group, injuries occurred more often while the subject was traveling at a reckless speed than at a low speed (Table 3; P < 0.001). Snowboarding injuries occurred significantly more frequently on a medium slope than did skiing injuries (Table 4; P =
180
T. Takakuwa and S. Endo: Snowboarding injuries
Table 3. Speed Speed Total no. of subjects Reckless Safe Low Stopped Unknown
Snowboarding n (%)
Skiing n (%)
138 18 (13.4) 78 (56.5) 25 (18.1) 5 (3.6) 12 (8.7)
128 6 (4.7) 49 (38.3) 52 (40.6) 4 (3.1) 17 (13.3)
Table 4. Gradient
Discussion
Gradient Total no. of subjects Medium Gentle Unknown
Snowboarding n (%)
Skiing n (%)
138 95 (68.9) 28 (20.3) 15 (10.9)
128 77 (60.2) 49 (38.3) 2 (1.6)
40" No. of injuries
I
20
O'
II
r
<1
differences between snowboarding and skiing injuries with respect to the surface of the slope or weather conditions. Injuries to both groups occurred most frequently in early January (the peak holiday snow season). The peak time of day was between 11 and 14:00h, and the highest incidence was on Saturdays and Sundays (the days on which the greatest number of people participate in these sports).
m 1
<2
<3
1
|
<4
_! 4<
duration of sports activity (hrs) Fig.1. Duration of sports activity on the day injury was sustained. Open columns, Snowboarding injuries; dark columns, skiing injuries 0.006). The duration of sporting activity was significantly longer in subjects who sustained snowboarding injuries than in those who sustained skiing injuries (Fig. 1; P = 0.01). The distribution of skill level in the snowboarding injury group was: beginners, n = 92 (66.7%), middle level, n = 25 (18.1%), and advanced, n = 7 (5.1%). The number of injuries in subjects at each skill level did not differ between snowboarding and skiing. The surface condition had been "smooth" and the weather "fair" at the time more than half of all patients had sustained the injuries. There were no significant
In snowboarders, we found a higher incidence of injuries to the upper half of the body than to the lower half, as previously reported in Japan. 7 Reports from countries other than Japan have indicated an equal incidence of injuries to the upper and lower halves of the body. 1,2,5 We believe the reasons for this discrepancy are (1) Resort, because, at ski slopes in Japan, the slope is smooth and well packed (as it is at the "H"), when the subjects: fall, their boards are seldom caught on the slope and their legs are seldom twisted. (2) Protective movements of the legs at the time of the fall are restricted, since the rider's feet are fixed to the board with bindings. This results in the hard impact being directly transmitted to various points on the upper half of body. (3) Injuries often occurred as the rider fell after trying to do a "trick jump" on the slope. 4 In this situation, snowboarders fall forward or backward, and place their hands on the slope for protection. (4) Collision (18.7% of cases); collisions usually involve the upper half of the body, as demonstrated in previous studies of skiing injuries. 6 Collision injuries in snowboarding may also cause injuries to the upper half of the body. Injury to the knee joint was less frequent in snowboarders than skiers, and the frequency of injury to the ankle joint and/or lower leg was the same for snowboarders and skiers. We have previously reported that these injuries could be caused by the external rotation of the lower limb, with the board acting as a lever arm, and that soft boots, which cannot fix the ankle joint, could contribute to these fractures. 4 At present, snowboarding footwear falls into two categories: soft and hard boots. In Japan, 73.4% of riders choose the soft boots, while the hard boots are used mainly by competitive or expert riders. 7 As the anatomic site of skiing injuries has been shown to change from the ankle joint to the knee, depending on the type of boot, it is possible that improvements in snowboarding equipment may also change the site of injury. ~,5 Since it is more difficult to shift the center of balance and to edge on a snowboard than on skis, snowbarding is probably not suited for quick turns or sliding at high speed; indeed, the incidence of injuries due to
T. Takakuwa and S. Endo: Snowboarding injuries u n c o n t r o l l a b l e m o t i o n on a m e d i u m slope was higher for s n o w b o a r d i n g than for skiing. S n o w b o a r d i n g has advantages over skiing in that it allows sliding on soft snow or deep, wet, and h e a v y snow, this being b e c a u s e the s n o w b o a r d has a large area of c o n t a c t with the surface of the slope. H o w e v e r , since almost all ski slopes in J a p a n are p r e p a r e d for skiing only, i.e., the surface is s m o o t h and well-packed, these conditions m a y m a k e it t o o difficult for s n o w b o a r d e r s to c o n t r o l their boards. It is necessary in future to create slopes that are safe and enjoyable for s n o w b o a r d riders as well as skiers. In the present study, of s n o w b o a r d e r s and skiers who were using the same slope, there was n o difference bet w e e n the groups in injuries sustained with respect to the time of day, day of the week, surface conditions, or weather. F u r t h e r m o r e , the slope was gentle, with an average gradient of less than 20 degrees, so that injuries for b o t h groups were similar at each skill level. In previous studies, 1,2,5,7s n o w b o a r d i n g injuries w e r e r e p o r t e d to be m o r e c o m m o n in beginners t h a n in those with experience. This p r o b a b l y reflects the fact that m o s t riders are lacking in experience and have yet to learn the relevant techniques. It is r e c o m m e n d e d that
181 s n o w b o a r d e r s take lessons to learn the p r o p e r technique and the general principles of slope safety; the potential for injury would thus be reducied.
References 1. Abu-Laban RB. Snowboarding injuries; an analysis and comparison with alpine skiing injuries. Can Med Assoc J 1991;145:1097103. 2. Bladin C, Giddings P, Robinson M. Australian snowboard injury data base study - - a 4-year prospective study. Am J Sports Med 1993;21:701-4. 3. Blitzer CM, Johnson RJ, Ettlinger CF, et al. Downhill skiing injuries in children. Am J Sports Med 1984;12:142-7. 4. Ohuchi S, Takakuwa T, Endo S, et al. Fractures caused by snowboarding (in Japanese). Rinsho Sports Igaku 1995;12: 1295-300. 5. Pino EC, Colville MR. Snowboard injuries. Am J Sports Med 1989;17:778-81. 6. Takakuwa T, Yasui Y, Endo S, et al. Skiing injuries caused by collisions (in Japanese). Rinsho Sports Igaku 1994;11:14227. 7. Takakuwa T, Ohuchi S, Endo S, et al. Injury and epidemiology of snowboarding (in Japanese). Seikeigeka (Orthop Surg) 1994;45:1697-701.