Unsurprisingly, helmets don't protect your arms.
In 2021, riders have a lot of choices in protective gear. No matter what decisions we ultimately make, it’s generally accepted that helmets and other proper protective motorcycle gear can reduce or even prevent serious injuries. From helmet certifications, to Sharp safety ratings, to abrasion tests and CE-level ratings on motorcycle armor, there are a lot of considerations to take into account when choosing how best to protect ourselves.
Where does the human element come into play, though? A group of seven international medical researchers based in the U.S. and Israel just published a new study in March, 2021, about this very subject.
It’s called “Motorcycle crashes and upper extremity trauma,” and it was published in the peer-reviewed, open access medical journal SICOT-J (the official journal of the Société Internationale de Chirurgie Orthopédique et de Traumatologie, or the International Society of Orthopedic Surgery and Traumatology).
The study retrospectively analyzed data collected from patients at a single level one trauma center, and who were involved in motorcycle crashes between June 2002 and December 2013. For reference, level one trauma centers are equipped to handle the most severely injured patients. Trauma centers range from levels one to five, with level five centers sending more critically injured patients to centers at levels one through three.
Data collected included the following:
- Basic patient demographics
- Helmet use
- Toxicology (to define “intoxication”, the study included any rider with any blood alcohol content recorded, not only those over the legal limit)
- Bony injury
- Injury Severity Score (a scale that standardizes injury severity based on the worst injury of 6 bodily systems, with points values calculated out of a total of 75)
- Glasgow Coma Scale (a scale to calculate traumatic brain injury severity using a points system from 1 to 15, with lower numbers indicating greater severity)
- Hospital length of stay
- Cost (direct medical care costs were included; cost of lost productivity and/or wages or other non-hospital-related concerns were not)
Limitations noted by the researchers include:
- Under-representation of non-intoxicated and/or helmeted patients. That’s because only patients with injuries severe enough to require treatment in a level one trauma center were included. The research team also noted that fewer helmeted riders tend to require hospitalization after crashes, as compared to non-helmeted riders.
- Non-helmeted and/or intoxicated riders are more likely to die at the scene, and this study did not include those who either died on scene, or upon initial resuscitation in the trauma bay.
- Since this was a retrospective study, the researchers say that it wasn’t as complete as it could have been. It analyzed data that the trauma center had previously collected on its own, so researchers couldn’t determine what categories of data they wanted to collect with specificity ahead of time.
- The research team also reported that “one potential confounder of note is other protective equipment, such as motorcycle jackets.”
Researchers were specifically concerned with recording upper extremity injuries, which they define as those located from the shoulder to the fingertips. As a result, that last limitation particularly stands out to me, the rider who is writing this piece. What kind of motorcycle jacket and/or gloves you’re wearing can make a difference, as can fit, armor placement, type of armor, whether you’ve crashed in that gear before, and a whole host of other factors. While it’s not reasonable to assume that a level one trauma center is going to note all those details down, having at least some notion of whether any other safety gear was involved would be a useful avenue of future inquiry.
Also, while this study covered a range of time between 2002 and 2013, expanded motorcycle crash info from the surrounding area that sent patients to that trauma center would be useful for a bigger-picture take. It’s beyond the scope of this study, but additional questions could inform the design of future studies in this area.
For example, what riders crashed, but didn’t end up in a level one trauma center? Was it because their injuries weren’t severe enough, perhaps because they were wearing protective gear? If so, what protective gear were or weren’t they wearing? Was it because they died? Were any patients wearing airbag vests or jackets, and if so, what difference did they make? The information presented here is a start, but we’d very much like to see additional studies with a variety of scopes on this subject.
During the course of this study, motorcycle crashes generated 40 percent of the total road traffic-related trauma patients at the level one trauma center surveyed. Out of a total of 37,086 patients entered into the trauma registry for that 2002 to 2013 time period, 1,066 (or 2.9 percent) had been in a motorcycle crash. 571 of those patients had at least one upper extremity injury, either to bony or soft tissue. Additionally, 338 upper extremity fractures were observed in 271 separate patients.
A full 67.1 percent of patients with upper extremity injuries were sober, but were also not wearing helmets. Of the bone fractures observed, 42.6 percent were in the hand, 41.7 percent were in the forearm, and 15.7 percent were in the humerus (or upper arm). 15.4 percent of these patients had an upper extremity joint dislocation, with acromioclavicular (AC) dislocation as the most common variant, at 22.7 percent. Only 6.3 percent of patients had soft tissue injuries.
Digging into helmet use, researchers noted that non-helmeted patients had a greater number of proximal (closer to the body) humerus fractures than helmeted patients. However, there was no difference noted between helmeted and non-helmeted patients in forearm fracture location. It’s unclear what the correlation between wearing a helmet or not and greater incidence of proximal humerus fractures may indicate.
Perhaps unsurprisingly, non-helmeted patients arrived at the hospital with quantifiably more severe injuries than helmeted ones. These patients arrived with ISS numbers greater than 30 (75 is the highest number on that scale), and/or GCS scores lower than 9 (lower numbers are worse, scored out of 15).
Helmeted patients were more likely to have upper extremity injuries, either of bony or soft tissue. Presumably, that’s because you’re more likely to put your arms out in a crash if you’re conscious, although that wasn’t explicitly called out in this study.