Tuesday, June 7, 2016

Bicycle helmets

We've had great weather here in the Pacific Northwest. I usually don't start riding my bicycle to work until late April or May, but this year I started riding in February. I few weeks ago I rode the first segment of the Olympic Discovery Trail and plan to ride the entire 130 miles from Port Townsend to La Push later this summer (Yes Twilight fans, that's vampire and werewolf country).

In April I took a longer route home from work through an area of the city where I had not ridden before. My front wheel got stuck in a railroad track and I had a hard fall. I picked myself up, got back on my bike, and rode home. It wasn't until I got home and took my helmet off that I realized that I must have hit my head during the fall because my helmet was cracked from one side to the other.

I didn't remember hitting my head and didn't think much of it at the time. I had a huge bruise on my left hip, an abrasion on my left arm, and the impact to my helmet was on the left side; all consistent with falling on my left side. What wasn't consistent was the abrasion on my right knee and that the most significant damage to my bike was to the rear derailleur, which is on the right side of my bike.

I went to work the next day, which was probably a mistake. It wasn't until I was recounting the accident to my coworkers that I realized that I didn't remember the accident. I remembered getting my front wheel stuck in the railroad track, and I remembered getting on my bike and riding away. I remembered being a little dazed at the time, but I knew where I was, how I got there, and how to get home. I don't know if I lost consciousness, but there was a man in a pickup who kept asking if I wanted him to call 9-1-1. At the time, I was unaware of how serious my accident had been. I left work early and went to an urgent care to get myself checked out.
A concussion is defined as injury to the brain caused by a hard blow or violent shaking, producing a sudden and temporary impairment of brain function, such as a brief loss of consciousness or disturbance of vision and equilibrium.

The characteristic loss of consciousness is believed to result from rotational forces exerted on the upper midbrain and thalamus, impairing the function of the reticular neurons. Headache, nausea, dizziness, irritability, and impaired ability to concentrate can persist for days after the event. Persistence of these symptoms for weeks is called postconcussion syndrome and can last from 1 month to a year.

Stippler, M. (2016). Craniocerebral trauma. In R. B. Daroff, J. Jankovic, J. C. Mazziotta, & S. L. Pomeroy (Eds.) Bradley's neurology in clinical practice, 7th Ed. [Electronic version]. Elsevier.

As a neuro nurse, I know that even a minor brain injury can cause profound disabilities. The realization that I had a concussion frightened me. I kept wondering if my difficulty concentrating and irritability were postconcussion syndrome or because I had difficulty sleeping. I kept wondering if I had difficulty sleeping because of postconcussion syndrome or because I had a huge, painful bruise on my hip. What's most frightening is thinking what might have happened if I had not been wearing a helmet.

Like a lot of you, I grew up riding a bike without wearing a helmet. We all turned out okay, didn't we? Not all of us. A lot more children died in bicycle accidents in the past than now.

CDC, 2015
There are several reasons fewer children die in bicycle accidents now. One possibility is that children ride bicycles less frequently than in the past. Bicycle helmets reduce the risks injuries and death from bicycle accidents (Attewell et al., 2001; Hooten & Murad, 2014; Persaud et al., 2014; Thompson et al., 1999) and helmet laws are also associated with decreases in deaths from bicycle accidents (Markowitz & Chatterji, 2015; Wesson et al., 2008).

Like any preventive measure, bicycle helmets do not completely eliminate the risk of injury and death. The fact that I can't remember my accident is evidence of that, but I doubt that I would have been able to return to work as soon as I did, if at all, had I not been wearing a helmet.

This is the first time I've been in a serious bicycle accident since I was a teenager. It's also the first time I've had a concussion. It has been a frightening experience. As parents, we want to protect our children from serious injuries. Brain injuries can cause lifelong neurological deficits. Getting Andrew to wear a helmet during our rides together was challenging at first, but I love him too much to let him ride without one. Now it's just part of the routine.

Children are more likely to wear a bicycle helmet if they ride with an adult who does and less likely to wear a helmet if they ride with other children who do not (Khambalia et al., 2005), so set a good example for them.


Please see these references for more information about bicycle safety and helmets:

I'd like to thank the staff at Tacoma Performance Bicycle for getting me back on the road so quickly after I damaged my bike. They repaired my bike and had me out of the store in less than 30 minutes. Of course, I bought a new helmet while I was in there.

American Academy of Pediatrics. (2001). Bicycle helmets. Pediatrics, 108(4), 1030-1032. http://pediatrics.aappublications.org/content/108/4/1030.long
Attewell, R. G., Glase, K., & McFadden, M. (2001). Bicycle helmet efficacy: a meta-analysis. Accident Analysis and Prevention, 33(3), 345-352.
Centers for Disease Control and Prevention. (2015). Bicycle deaths associated with motor vehicle traffic – United States, 1975-2012. Morbidity and Mortality Weekly Report, 64(31), 837-841. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6431a1.htm
Hooten, K. G. & Murad, G. J. A. (2014). Helmet use and cervical spine injury: a review of motorcycle, moped, and bicycle accidents at a level 1 trauma center. Journal of Neurotrauma, 31(15), doi:10.1089/neu.2013.3253. http://online.liebertpub.com/doi/abs/10.1089/neu.2013.3253
Khambalia, A., MacArthur, C., & Parkin, P. C. (2005). Peer and adult companion helmet use is associated with bicycle use by children. Pediatrics, 116(4), 939-942. http://pediatrics.aappublications.org/content/116/4/939
Markowitz, S. & Chatterji, P. (2015). Effects of bicycle helmet laws on children's injuries. Health Economics, 24(1), doi:10.1002/hec.2997. http://onlinelibrary.wiley.com/doi/10.1002/hec.2997/abstract
Persaud, N., Coleman, E., Zwolakowski, D., Lauwers, B., & Cass, D. (2012). Nonuse of bicycle helmets and risk of fatal head injury: a proportional mortality, case-control study. CMAJ, 184(17), doi:10.1503/cmaj.120988. http://www.cmaj.ca/content/184/17/E921.long
Thompson, D. C., Rivara, F., & Thompson, R. (1999). Helmets for preventing head and facial injuries in bicyclists. Cochrane Database of Systematic Reviews, 4, CD001855. doi:10.1002/14651858.CD001855. http://onlinelibrary.wiley.com/wol1/doi/10.1002/14651858.CD001855/full
Wesson, D. E., Stephens, D., Lam, K., Parsons, D., Spence, L., & Parkin, P. C. (2008). Trends in pediatric and adult bicycling deaths before and after passage of a bicycle helmet law. Pediatrics, 122(3), doi:10.1542/peds.2007-1776. http://pediatrics.aappublications.org/content/122/3/605


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