Gobbi et al7 investigated the incidence of injury in a 12-year period among adult and youth riders. The authors found a collision rate of 94.5% per year, with a 22.72% chance of injury per hour of riding and an average of 4.5 crashes per race. Of the 1,870 injuries reported in the study, 450 were fractures (50.9% in the upper extremity, 38% in the lower extremity). The other fractures occurred in the torso and axial skeleton. Twenty-six patients sustained spinal fractures, with eight resulting in permanent neurologic sequelae.
Luo et al8 investigated the rate of traumatic brain injury in youth riders occurring during one outdoor riding season. Among the riders who participated in the 4-month season, 48% experienced at least one episode of concussive symptomatology, and 78% of those riders sought medical management of those symptoms. Most riders who experienced concussive symptoms suspended their participation, with a mean time away from participation of 2.7 weeks. However, 24% of riders with concussive symptoms continued to participate for the duration of the season without seeking medical treatment.
Adolescents with concussion symptoms require more time for recovery compared with their adult counterparts. In turn, this can negatively affect academic performance, social development, and future ability to participate in athletics.8 An estimated 90% of sport-related concussions are unidentified.4 Emergency department visits for sport-related traumatic brain injuries in the pediatric population have increased 60% in the past decade.4 The highest rate of emergency department visits for sport-related concussions occurs in patients in the 10- to 14-year age group.4 Importantly, <10% of patients with a concussion experience loss of consciousness (LOC), yet one study involving pediatric riders found that 95% of patients diagnosed with head injury had LOC.4 The authors hypothesized that the speed and high-impact forces generated in a motocross crash may cause patients to have a higher incidence of LOC than in other sports. They also hypothesized that mild and moderate concussion episodes were not captured in the analysis because of underreporting of concussive symptoms.
It is thought that the incidence of concussion is underestimated because riders likely underreport symptoms. Many athletes note experiencing pressure to underreport because of a culture of toughness or a fear of having restrictions placed on themselves or their sport.8 Such underreporting has been noted in other cohorts, with 43% of student athletes with concussions knowingly hiding their symptoms and 22% indicating that they would do so in the future.8
Spine injuries account for only 5.8% of all motocross-related fractures; however, one third of these injuries lead to permanent neurologic damage.7 Spinal fractures sustained on human-made stadium tracks carry a 46% increase in producing permanent neurologic sequelae, compared with injuries sustained on outdoor natural tracks.7 Fewer fractures are seen in pediatric spines than in adult spines because of the greater ligamentous laxity of pediatric spines. Therefore, substantial displacement in pediatric spines may occur, resulting in permanent spinal cord injury, without evidence of a fracture.1
One study involving adult and youth riders in southern California demonstrated that 9% of injuries were spinal fractures, with most occurring in the thoracic region.9 Other studies confirm that the thoracic spine is the most commonly injured region of the spine. This injury pattern is thought to result from hyperflexion of the rider’s spine upon impact.9 Axial loading is concentrated at the point of maximal flexion and results in injuries predominantly in the midthoracic spine.9
Acute injury to the spine is not the only concern in youth motocross racers. Radiographic evaluation demonstrated increased degenerative cervical and thoracic findings in youth motocross riders, compared with age-matched controls who participated in hockey, football, and soccer.5 These findings may be attributable to the repetitive microtrauma resulting from the jarring of the bike on the track or may be a cumulative effect of multiple high-velocity accidents sustained in practice and competition.5
The numbers of severe and fatal injuries to children who ride two-wheeled motorized vehicles have recently been increasing.10 , 11 Therefore, injury prevention must be of paramount concern. Primary injury prevention includes appropriate training, the use of protective equipment, proper maintenance of the vehicle, and attention to environmental factors. Parents and children must be counseled about proper safety precautions and the potential for severe injury during motocross activities.6 Parents and coaches need to weigh the benefits of participation with the frequency of injuries, missed academic time, and cost of medical treatment.2
Children should undergo age-appropriate training before participation is allowed. Direct adult supervision should occur at all times.2 Recommendations for helmets include a lightweight material that provides adequate levels of impact protection, integrated padding, and a tightly fastened double chin strap.8 Appropriate helmet fitting with assistance from an expert is associated with a 41% decrease in reported concussion symptoms.8
Concussion awareness is improving. All 50 US states have legislation regarding concussion management in children.4 The AMA requires concussion training and baseline testing with the ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing; ImPACT Applications, Inc) assessment before a license is granted. After concussion symptoms develop, the rider must pass a subsequent ImPACT test before resuming competition.8 However, room for improvement remains. Efforts need to be undertaken to improve concussion identification and management. Riders must be cognizant of the need to avoid racing while experiencing concussion symptoms to prevent so-called second-impact syndrome, which can result in brain herniation and death.8 After concussive symptoms have resolved, riders should participate in supervised, progressive return-to-ride programs before returning to competitive racing.
A large number of motocross injuries are sustained in collisions with other riders or when riders are run over by other cyclists.2 Some authors have suggested that having fewer riders on the course could reduce the frequency and severity of injuries.2 Others have hypothesized that the increased numbers of injured patients could be attributable to an increase in the number of young riders, the use of faster and more powerful vehicles, the increased availability of vehicles, and more reckless riding.10
Motocross may not be an appropriate sport for all participants. Some pediatric patients with repeated injuries may not have the required dexterity, maturity, and coordination to safely operate a motor vehicle.2 The exact age and levels of physical development, strength, coordination, emotional maturity, and judgment at which children can or should be able to ride motorbikes are difficult to determine.10 The current recommendation by the American Academy of Orthopaedic Surgeons is that children aged <16 years should not operate motorbikes.12
References printed in bold type are those published within the past 5 years.
1. Alberto G: Motocross injuries
: Incidence, management, and prevention
, in Doral MN, Karlsson J, eds: Sports Injuries
. Berlin, Germany, Springer, 2013, pp 1–15.
2. Larson AN, Stans AA, Shaughnessy WJ, Dekutoski MB, Quinn MJ, McIntosh AL: Motocross
morbidity: Economic cost and injury distribution in children. J Pediatr Orthop 2009;29(8):847–850.
3. American Motorcyclist Association: 2015 AMA Racing Rules Governing Pro/Am, Standard, ATV, and Youth
Competition. Pickering, OH, American Motorcyclist Association, 2015. http://http://www.d14enduro.org
/rules/2015_ama_racing_rulebook.pdf. Accessed January 16, 2018.
4. Daniels DJ, Clarke MJ, Puffer R, Luo TD, McIntosh AL, Wetjen NM: High occurrence of head and spine injuries
in the pediatric population following motocross
accidents. J Neurosurg Pediatr 2015;15(3):261–265.
5. Daniels DJ, Luo TD, Puffer R, et al: Degenerative changes in adolescent spines: A comparison of motocross
racers and age-matched controls. J Neurosurg Pediatr 2015;15(3):266–71.
6. Kennedy RD, Potter DD, Osborn JB, et al: Childhood motocross
: High-velocity, focal force to the chest and abdomen. BMJ Open 2012;2(6):e001848.
7. Gobbi A, Tuy B, Panuncialman I: The incidence of motocross injuries
: A 12-year investigation. Knee Surg Sports Traumatol Arthrosc 2004;12(6):574–580.
8. Luo TD, Clarke MJ, Zimmerman AK, Quinn M, Daniels DJ, McIntosh AL: Concussion
symptoms in youth motocross
riders: A prospective, observational study. J Neurosurg Pediatr 2015;15(3):255–260.
9. Gorski TF, Gorski YC, McLeod G, et al: Patterns of injury and outcomes associated with motocross
accidents. Am Surg 2003;69(10):895–898.
10. Pomerantz WJ, Gittelman MA, Smith GA: No license required: Severe pediatric motorbike-related injuries
in Ohio. Pediatrics 2005;115(3):704–709.
11. Collins CL, Smith GA, Comstock RD: Children plus all nonautomobile motorized vehicles (not just all-terrain vehicles) equals injuries
. Pediatrics 2007;120(1):134–141.
12. Larson AN, McIntosh AL: The epidemiology of injury in ATV and motocross
sports. Med Sport Sci 2012;58:158–172.
Keywords:© 2018 by American Academy of Orthopaedic Surgeons
concussion; injuries; motocross; prevention; safety; spine; youth