Cycling is an activity with high levels of participation, and which is growing in popularity. There is an international push to increase cycling participation.1 This is due to the inherent health, environmental, and transport benefits of cycling.1,2,3 The low-impact nature of cycling makes it an appropriate component of rehabilitation, as well as a fitness activity for adults with degenerative joint disease. 1,3

Injuries

The number of cyclists in the United States has grown substantially over the past 10 years. The health benefits of cycling have been clearly established by research, with studies showing consistent positive dose-response relationships between the amount of cycling and improved fitness, decreased risk of all-cause mortality, cardiovascular disease, colon cancer morbidity, and obesity. Societal benefits of a modal shift from car travel to cycling also have been shown, including a reduction in air pollution and traffic accidents.4 Despite its health benefits, however, cycling also is associated with a variety of injuries, which will briefly be reviewed.

Overuse

Overuse injuries are reported in 45% to 90% of mountain bikers. 1 Cycling can cause microtrauma to the body over time in both areas of contact as well as to areas of and noncontact due to repetitive forces and vibration. These exposures without out adequate recovery can lead to fatigue and make the cyclist vulnerable to injuries. Classically, overuse injuries include are related to the bicycle fit or improper training techniques. The most common lower extremity injury include knee pain such as patellofemoral pain syndrome due to factors such as the bicycle saddle being too low or in a forward position. The most common upper extremity injuries include wrist pain or hand numbness due to poor weight distribution across the handlebars. Other overuse injuries include low back pain and neck due to poor cycling position and mechanics. 1,5

Traumatic

Although, non-traumatic injuries predominate within recreational cyclists, may riders who travel at high speeds, in large groups, over technical terrain, or in traffic are at risk for traumatic injury. In a study of elite cyclists during a multiday road race, half of the injuries documented were traumatic, most involving skin and soft tissue. 2,5

In 2011 Nelson et al noted that mountain biking injuries have decreased significantly from 1994 to 2007.3 However, there still were approximately 15,000 bicycle related injuries each year. The most common injuries were upper extremity fractures (10.6%) and shoulder fractures (including clavicle; 8.3%). 3 Overall, fractures accounted for 26.5% of mountain bike–related injuries, followed by soft tissue injuries (24.0%) and lacerations (20.5%).3 The majority of mountain bike–related injuries were attributed to falls (69.9%) or being thrown from the bike (14.1%).3

Injury Prevention

The high prevalence of injury and pain, both traumatic and overuse, in cycling and the increasing popularity of the sport create concerns about injury prevention and a need to understand risk factors associated with injury. Historically, overuse injury management in cyclists has emphasized features of bicycle geometry such as seat height and seat fore-aft position, seat to handle bars distance, as well as cleat alignment and position. Bicycles are designed for specific demands, from racing performance, to comfort and stability in traffic, to carrying heavy loads or children. The frame geometry, handlebar shape, saddle, and pedal system are selected based on the cyclist’s anatomical measurements and the desired body position and function. Improper body position on the bicycle can contribute to a number of overuse injuries.6 Small adjustments, particularly at the body’s interface with the bicycle at the seat, handlebars, and pedals can affect the rider’s biomechanics throughout the kinetic chain, improving comfort, efficiency, and power generation (Figure 1). 1,6

bicycle picture

Figure 1: Schematic bicycle diagram. CS, chain stay; TT, top tube; R, reach; ST, seat tube; STA, seat-tube angle; HT, head tube; HTA, head-tube angle; WB, wheel base; TT, top tube; SH, saddle height; FO, fork offset.1  

Conclusion

The evaluation and management of cycling injury is a collaborative process involving athletes, physicians, physical therapists, bike fitters, and, for some cyclist, a coach. . Correction of anatomical factors, bike fit, cycling technique errors, and training habits can all improve comfort and enjoyment on the bicycle as well as avoid preventable injuries.

References

1.     Ansari M, Nourian R, Khodaee M. Mountain Biking Injuries. Curr Sports Med Rep. 2017;16(6):404-412.
2.     Khodaee M, Deu RS, Mathern S, Bravman JT. Morel-Lavallée Lesion in Sports. Curr Sports Med Rep. 2016;15(6):417-422.
3.     Nelson NG, McKenzie LB. Mountain biking-related injuries treated in emergency departments in the United States, 1994-2007. Am J Sports Med. 2011;39(2):404-409.
4.     Rajapakse B, Horne G, Devane P, Rajapaske BN. Forearm and wrist fractures in mountain bike riders. N Z Med J.
5.     McGrath TM, Yehl MA. Injury and illness in mountain bicycle stage racing: experience from the Trans-Sylvania Mountain Bike Epic Race. Wilderness Environ Med. 2012;23(4):356-359.
6.     Leavitt TG, Vincent HK. Simple Seat Height Adjustment in Bike Fitting Can Reduce Injury Risk. Curr Sports Med Rep. 2016;15(3):130.