Humerus Fracture More Common in Snowboarding Accidents Than With Skiing
Physical Therapy in Port Townsend for Skiing
Downhill skiing and snowboarding are popular winter sports in the United States. It's estimated that there are over five million visits to ski hills and resorts per winter season. Despite the increasing popularity, increased safety awareness has resulted in an overall decrease in ski injuries over the past 50 years. Latest statistics show that the rate dropped from 7.6 injuries for every 1,000 ski days in the 1950s to 3 injuries per 1,000 days now. That being said, arm and shoulder injuries have increased from one in four injuries to one out of every two injuries. So, despite the improvement in injuries to the lower body, not much has changed with the upper body. If we compare snowboarding injuries to skiing injuries, we find that injuries of the arm happen twice as often in snowboarding over skiing.
An earlier study, by Dohjima and colleagues, looked at 2,552 snowboard injuries and 5,048 skiing injuries during one season. They found in snowboarders, the radius (the forearm bone in the innermost part of the arm) was broken in 48 percent of cases, while the humerus (the second forearm bone, more towards the outside of the arm) was broken in 7.7 percent of cases. The clavicle (collar bone) was broken in 15 percent. In skiers, however, the radius was broken only in 5 percent of the accidents.
The authors of this article wanted to investigate the risk factors associated with fractures of the humerus resulting from skiing and snowboarding. Their list of potential risk factors included the gender of the skier/snowboarder, snow conditions, experience in skiing or snowboarding, helmet use, cause of the accident, age, and the conditions of the day.
Patients who participated in the study were injured while skiing or snowboarding and they had been transported or presented themselves to a clinic at a base lodge at the bottom of a major ski area since the 1972/73 season (34 seasons total) for skiers and since 1988/89 for snowboarders (18 seasons). In all, there were almost 7 million skiers and over 700,000 snowboarders during this period. In all, among 18,692 ski injuries and 2,270 snowboard injuries, the researchers identified 327 humerus fractures, 49 snowboarders (2.2 percent of snowboard injuries) and 278 skiers (1.5 percent of ski injuries). However, although the number of snowboarder humerus fractures was smaller in total, they actually happened more frequently, given the shorter period of time (18 years versus 34 years) and the lower number of snowboarders.
Shoulder dislocations were also common. Among the skiers, there were 640 dislocations over the 34 years and 42 of them were associated with fractured humerus. Among the snowboarders, there were 56 dislocations over 18 years, but only one was associated with a fractured humerus.
The researchers analyzed the risk factors and found no differences between males and females in either skiing or snowboarding for fractures of the humerus, although when looking at all injuries, more female skiers than male skiers did get hurt. There wasn't any difference in snowboarding. After the injuries, the patients were asked about the snow conditions, their skiing level (beginner through to expert), helmet use, cause of accident, age, and whether they were left sided or right sided.
The results showed that more humerus fractures and overall injuries occurred on dry powder/packed powder conditions for both skiers and snowboarders. Being a beginner or novice skier did not increase the risk of a broken humerus but the risk of an overall injury was higher in this group. Snowboarders, however, had a higher risk of both a humerus fracture or an overall injury if they were beginners or novice. Helmets didn't affect humerus fracture in either group but it did lower the risk of overall injuries.
When looking at the causes of the accidents, there was a significant difference between skiers and snowboarders. Only 5.4 percent of broken humerus were caused by jumps in skiers, while 28.3 percent were caused by jumps among snowboarders. The average age of skiers who fractured the humerus was 37 years compared with the average age of uninjured skiers at 29.7 years. With snowboarders, it was 18.9 years for fractured humerus and 24 for those who had no injury.
The researchers looked at what side the humerus fractures were. Among snowboarders, most (71.4 percent) were on the left side, but only 53.8 percent were on the left side for skiers. Someone who leads with their left foot is considered to be regular footed. Among regular-footed snowboarders, 77.8 percent of the humerus were on the left. Wrist injuries, however, were more likely to happen on the right side of regular footers.
The study showed that snowboarders had a higher rate of humerus fracture than skiers, almost 50 percent higher. The authors of this article suggest that this may have something to do with the apparatus - a snowboarder is locked into the bindings, while a skier can release the bindings quickly. By not being able to get out of the bindings, the only way to break your fall is by putting out your arms. Because the falls are different, between snowboarders and skiers, the breaks are a bit different as well. Skiers tended to have breaks higher up in the arm, while boarders lower down near the wrist. As well, the locked in position and the sideways descent of snowboards contributes to the majority of humerus fractures being on the left, unlike skiers who are facing forward as they move down the hill.
The authors were surprised at the finding that powder/packed snow contributed to a higher risk of a fracture, considering that these fractures usually occur as the result of falling on a hard surface, such as ice. The age differences weren't as surprising: skiers were generally older than average when injured and snowboarders younger than average when injured. Although they didn't have data to support their thoughts, the authors feel that the ages could be due to younger snowboarders being inexperienced and more likely to fall, while older skiers may not have the flexibility and strength of the younger skiers.
Ref: Benjamin T. Bissell, MD et al. Epidemiology and Risk Factors of Humerus Fractures Among Skiers and Snowboarders. In The American Journal of Sports Medicine. October 2008. Vol. 36. No. 10. Pp. 1879-1888.