Snowboarding is an increasingly popular winter sport in which participants ride an epoxyfiberglass board (resembling a large skateboard) down a ski slope or on a half-pipe ramp, a specialized snow structure used for performing tricks. Introduced in the United States in 1965 when Sherman Poppen bolted two skis together, snowboarding became popular with the introduction of commercial snowboards in the late 1970s. Today, with more than 3.4 million participants, snowboarding is the fastest growing winter sport in the United States. Snowboarders now make up 20 percent of the visitors to U.S. ski resorts. The National Sporting Goods Association estimates that since 1988, the number of snowboarders has increased 77 percent, whereas the number of skiers has fallen 25 percent. The popularity of snowboarding was further boosted after its introduction as an Olympic sport at the 1998 Winter Games in Nagano, Japan.
Snowboarding differs from downhill skiing in many respects. The most important difference is that snowboarders ride with both feet affixed by non-releasable bindings to a single board. Unlike downhill skiers, snowboarders stand perpendicular to the long axis of their boards (Figure 1). Furthermore, snowboarders do not use ski poles, but use their hands and arms for balance, much like skateboarders or surfers.
Knowing the type of equipment used and the rider's position on the board is important in evaluating injuries. Traditional snowboards are symmetric, allowing the snowboarder to travel backward easily, that is, lead with the tail of the board (a move called a “fakie” by snowboarders). Asymmetric boards that enhance freestyle, slalom and giant slalom events are more recent introductions. Traditionally, snowboard riders use their left foot as the forward foot and face toward the right side of the board (known as the “frontside”). Occasionally, snowboarders ride in a reverse position, called “goofy-footed.”
Snowboarding boots come in three styles: soft, hard and hybrid. Traditionally, snowboarders use soft boots. The current soft snowboard boot is made of leather or synthetic material that allows moderate stability yet is balanced by moderate flexibility. The advantages of soft boots are increased maneuvering ability and comfort. “Sorrel-type” soft boots are worn by 75 to 90 percent of recreational snowboarders. Some beginners wear moon boots or hiking boots, both of which lack stability and may lead to a higher injury rate. These types of boots should not be used for snowboarding.
Hard boots provide greater ankle support and increased control, and are primarily worn by racers.
The increasingly popular hybrid boots are relative newcomers to the snowboarding scene. This classification includes boots that are constructed with a soft leather or synthetic outer shell and a stiff inner boot. Another design is constructed with a hard shell base and a soft upper component. This combination balances the increased comfort and maneuvering ability of soft boots with the increased stability of hard boots. Since each boot style places the body under different stresses, knowing the type of boot worn is important in determining the risk of injury.
BINDINGS AND SAFETY EQUIPMENT
Most snowboard bindings are non-releasable. Soft bindings are molded plastic shells with buckle systems that are used with soft boots and include a high back to give extended Achilles tendon support. The plate-type bindings consist of a steel and plastic base plate with heel and toe clips and are typically used with hard boots. Safety equipment includes helmets, face guards, goggles, forearm guards and wrist guards. Unfortunately, safety equipment is rarely used by recreational snowboarders.
Although advanced snowboarders may try more dangerous maneuvers such as jumps and other aerial tricks, beginning snowboarders are the most frequently injured. Almost one quarter of snowboarding injuries occur during a person's first experience,1,3,4 and almost one half occur during the first season of snowboarding.2–8 A typical first snowboarding experience consists of a cycle of brief rides followed by falls; since falling is the leading cause of snowboarding injuries, the beginning snowboarder is at high risk for injury.3
Jumps are the second most common cause of injuries and may be associated with head, facial, spinal and abdominal injuries.4 Collisions are associated with 5 to 10 percent of injuries.3,4,8 Severe injuries that require referral to a tertiary trauma center are rare. The most common cause of severe injury is collision with a tree. Severe injuries usually involve the head (54 percent), abdomen (32 percent), bones (32 percent) and thorax (16 percent).9
Four to 8 percent of snowboarding injuries take place while the person is waiting in ski-lift lines or entering and exiting ski lifts.8,10 Snowboarders push themselves forward with a free foot while in the ski-lift line, leaving the other foot (usually that of the lead leg) locked on the board at a 45- to 90-degree angle, placing a large torque force on this leg and predisposing the person to knee injury if a fall occurs. Equipment failures rarely cause injuries (0.5 to 1.2 percent).8,10
Although early studies showed that approximately one half of snowboarding injuries were located in the lower extremities, this pattern has changed with the evolution of snowboard boots and bindings. Currently, fewer than one third of snowboarding injuries are to the lower extremities (Table 1).1,3–8,10,11 The lead leg, which is at greatest risk, accounts for almost three quarters of such injuries.1,5,8 Injury location is related to boot type. Hard boots place the snowboarder at risk for fractures of the tibia and fibula at the level of the boot top, called “boot-top” fractures.2,6
|Study||Number of injuries||Upper extremity injuries (%)||Lower extremity injuries (%)||Wrist injuries (%)||Knee injuries (%)||Ankle injuries (%)|
|Pino and Colville, 19891||110||29.1||52.7||7.3||11.8||26.4|
|Ganong, et al., 19923||415||44||43||23.9||18.1||16.9|
|Bladin, et al., 19936||276||30||57||—||23||23|
|Warme, et al., 19957||47||—||—||—||17||21|
|Calle and Evans, 199510||487||38||34.1||19.9||15||12.5|
|Davidson and Laliotis, 19968||931||40||38||19||17||16|
|Chow, et al., 19964||355||58||16||20.3*||2.8||3.1|
On the other hand, soft boots give the snowboarder approximately twice the risk of ankle injury compared with hard boots.1,3,6 Ankle injuries account for almost 17 percent of snowboarding injuries. Almost 50 percent of the ankle injuries are fractures, which are usually easily diagnosed.3,4 However, “snowboarder's ankle,” a fracture of the lateral process of the talus, may be difficult to see on a standard ankle x-ray series12,13 (Figure 2). This fracture may comprise up to 15 percent of those ankle injuries in snowboarders that require medical evaluation. Physicians should maintain a high index of suspicion for snowboarder's ankle in a snowboarder with a “severe ankle sprain” that is persistently painful, has limitation of motion and fails to improve with appropriate management2 (Table 3). The mechanism of injury is a forcing of the ankle into dorsiflexion and inversion, which may occur during a landing from an aerial maneuver or a jump, especially when the landing has been over-rotated.
|Degree of injury||Location of injury|
|Head||Shoulder||Elbow||Wrist and hand||Trunk||Knee||Ankle|
|Common, less serious injuries||Soft tissue injuries*||Sprain||Soft tissue injuries*||Sprain||—||ACL sprain||Sprain|
|Soft tissue injuries*|
|Less common, more serious injuries||Concussion|
Closed head injury
CLASSIFICATION OF ANKLE INJURIES
Snowboarder's ankle injuries are classified by degree of severity. A type 1 fracture is an articular process chip fracture of the talus with no extension into the talofibular joint. A type 2 fracture is a single large fragment extending from the talofibular joint to the subtalar joint. A type 3 fracture is a comminuted fracture of the entire lateral process. A lateral plain ankle x-ray with the ankle in 10 to 20 degrees of inversion may be better than standard ankle views for viewing the fracture.12,13 Other diagnostic tests, such as computed tomographic scanning or magnetic resonance imaging, may be useful in evaluating these injuries.
TREATMENT OF ANKLE INJURIES
Treatment for a nondisplaced or minimally-displaced fracture (less than 2 mm) is a short-leg, partial-weightbearing cast for six weeks. Patients with large displaced fractures and comminuted fractures should be referred to an orthopedic surgeon for possible open reduction and internal fixation, and/or excision of the fragments.
Upper Extremity Injuries
Upper extremity injuries make up an increasing proportion of the total number of snowboarding injuries, rising from approximately one quarter of all injuries in the early 1990s to almost one half of all injuries today. The lead upper arm appears to be slightly more vulnerable to injury.1,8 The wrist is the most common site of injury, accounting for almost one quarter of snowboarding injuries (Table 2) and for one half of all fractures.3–5,10 Other common fracture sites are the clavicle and the elbow.3,4 The shoulder is the most common site of dislocation, accounting for almost two thirds of dislocations, followed by the elbow, which accounts for almost one quarter of total dislocations.3,4
Compared with skiers, snowboarders have a much higher risk of wrist injuries (23 percent versus 4 percent) and ankle injuries (17 percent versus 5 percent) but a lower risk of knee injuries (16 percent versus 38 percent).1,3–8,10,11 Despite the lack of releasable bindings, snowboard-related knee injuries tend to be less severe than those experienced by downhill skiers. This lower risk may be related to features that are unique to snowboarding: (1) the shorter length of the board results in a smaller potential lever arm and lower forces during twisting injuries, and (2) a single board decreases the number of edges that can get caught, thereby decreasing the chance of a twisting crash or of the knees rotating in different directions.
Although most snowboarders do not wear protective equipment, some snowboarders wear wrist guards similar to those worn by inline skaters. These wrist guards have been shown to be very effective in preventing wrist injuries in in-line skaters.14 Although protective equipment decreases the overall incidence of injury by reducing the force of impact, it may actually place the areas proximate to the device at increased risk, by shifting the distribution of impact forces. For example, skiers and snowboarders who wear hard boots are at greater risk for “boot-top” fractures, and in-line skaters are at greater risk for “wrist-guard–top” fractures.15,16 This effect is illustrated in a survey that included 21 snowboarders who had been injured while wearing wrist guards: although none of these persons had a wrist injury, six had a shoulder injury and four had radial shaft fractures.4 Novice snowboarders who refuse to wear wrist guards are advised to keep their hands in a “closed-fist” position while snowboarding. This hand position minimizes the temptation of snowboarders to check themselves with an open hand when falling, since falling on a hyperextended wrist increases the risk of injury. Falling backward was the mechanism of injury in almost three quarters of wrist injuries in one series.8 Since beginners are most likely to lose their balance and fall backward, they are most likely to benefit from wearing wrist guards. Some instructors have their beginning students use ski poles to decrease the frequency of falling.
Another frequent impact area in beginning snowboarders is the back of the head. Fortunately, the force load on the head is usually relatively mild since most of the force is first absorbed by the buttocks, back and upper extremities, and impact usually results only in headache. Many instructors recommend that beginning snowboarders wear a helmet during their initial attempts at the sport to prevent or reduce the severity of head injuries.