Mountain Bike Injury Study - What We Can Lean From The Stats

In this podcast I review the findings of a 2017 study on mountain biking injuries and give you my recommendations based on them for avoiding the most common injury patterns. You‌ ‌can‌ ‌stream‌ ‌or‌ ‌download‌ this episode ‌from‌ ‌the‌ ‌link‌ ‌below‌ ‌or‌ ‌you‌ ‌can‌ ‌find‌ ‌it‌ ‌on‌ ‌‌Itunes‌,‌‌ ‌Podbean‌,‌‌ ‌‌Spotify‌‌ ‌‌and‌ ‌all‌ ‌other‌ ‌major‌ ‌podcasting‌ ‌platforms.‌ ‌

Some people look at injury studies like this with a fatalistic approach of “that’s just how it is and there is nothing we can do to significantly change things”. I look at them and say “if people are getting hurt at a higher than normal rate, is there something we are doing wrong that is leading to it”?

Running Shoes is a good example of this - small changes to the status quo vs. a paradigm shift in how we look at running.

Is the industry getting it all wrong with the equipment and techniques we promote along with how we promote mountain biking to new riders?

Here are my big takeaways from the study linked to below:

https://journals.lww.com/acsm-csmr/fulltext/2017/11000/mountain_biking_injuries.10.aspx

Big Takeaway #1 - Mountain Biking has a higher than average rate of injuries in general and head/ spine and overuse injuries in particular.

• With almost a third of injuries occurring during the race, MTB is among the sports leading to high overall injury rates in Olympic sports (²⁰). During the 2012 Summer Olympics, 21% of mountain bikers reported acute or overuse injuries, half of which had led the cyclists to lose at least one training/race day (²⁰). Fifty percent of recreational bikers and 80% of professional mountain bikers have reported at least one major severe injury directly related to the sport (³⁵). Microtraumatization of contact and noncontact areas due to repetitive forces and vibration, in addition to fatigue, renders the rider vulnerable to overuse injuries (¹³). Such injuries are reported in 45% to 90% of mountain bikers (¹³). Injury-related cost of care for the cyclists can be a significant financial burden for cyclists and health care in general (⁴⁶). However, the potential risks of cycling are outweighed by the health-related benefits of riding a bike.
• The most common mechanism of acute severe injury for competitive mountain bikers has been falling forward (64.9%), and 85.6% of such injuries have occurred while riding DH (¹⁴). Falling forward had led to a significantly higher Injury Severity Score (ISS) and emergency department admission rates than falling to the side (¹⁴).
• Head injuries lead to concussions, skull and facial fracture, cerebral contusion, and intracranial hemorrhage. In one study, oromaxillofacial trauma, fractures, soft tissue injuries, and dental trauma accounted for 55%, 23%, and 22% of cases, respectively (²⁴). Dental trauma also has been reported in 25% of the mountain bikers.
• In 107 cases of acute spine injuries in MTB in a level 1 trauma center, 95% were male (¹⁸). Only two were professional cyclists and injured during a race. Mountain biking spinal injuries consisted almost 4% of all spinal injuries (¹⁸). Cervical spine injuries were diagnosed in 74% of cases. Eighty-four percent of riders had used helmets and/or body armor. Fifteen percent of patients had documented coexisting brain injury. The ISS did not differ significantly in those with helmet (16.4) versus those without helmet (16.3).
• Ulnar and median neuropathies are common among cyclists, with ulnar neuropathy (cyclist’s palsy) being present in 19% to 35% of the cyclists (⁴).
• Prevalence of knee pain is 20% to 27% among mountain bikers (¹³).
• With a prevalence of 16% to 43%, neck pain is a common complaint among mountain bikers (¹³).
• While the clipless shoes provide the cyclist with mechanical advantage in energy transfer chain during cycling, they potentially expose the cyclist to some injuries including metatarsalgia (⁶²) and Morton’s neuroma (³⁴).
• Low back pain (LBP) is a common complaint among mountain bikers with a prevalence of 24% to 41% (¹³).
• Genital area numbness (GAN) and erectile dysfunction (with prevalence of 50% to 91% and 13% to 24%, respectively) are two of the most common chronic injuries of genitourinary system in male cyclists (²⁷). Other complaints include dysuria, scrotal abnormalities, urogenital, and perineal pain. Impingement of the pudendal nerve in Alcock’s canal due to stretching, vibration, and ischemia has been proposed as the cause of pudendal neuralgia and paresthesia in cyclists (⁵¹). In contrast to road cycling, the more upright riding posture of mountain bikers leads to higher loading of buttocks area (⁴²). Poorly fitted bike, saddle type, increased riding distance, prolonged seated position without standing, and high body weight appear to be contributing factors. Correction of these factors, physical and manual therapy, and minimally invasive interventions to block or ablate the pudendal nerve may be effective treatment methods. Male mountain bikers also have a significantly higher rate of abnormal ultrasonographic findings in scrotums compared with noncyclists and road cyclists, (94%, 16%, 48%, respectively) (⁴⁶).

Big Takeaway #2: Downhill Riding/ Bike Parks are Significantly More Dangerous Than XC

• Various terrain conditions and participants in the sport have led to a variety of injury patterns among mountain bikers. With only severe injuries included in a study conducted in 1995, injury rate per exposure was similar between DH and XC races (³⁸). However, when comparing the injury rate per 1000 h, the DH cyclists had a significantly higher injury rate in comparison to XC cyclists. The injury rates were 7.5 and 3.1 per 1000 h for female and male XC cyclists, respectively (p = 0.01); while the rates were 46.8 and 42.7 per 1000 h for female and male DH cyclists, respectively (p > 0.05)(³⁸).
• An emerging trend is the growing number of mountain bikers attracted to mountain bike terrain parks (MBTP), which facilitate the DH rides and provide the cyclists with a variety of technical trail features, leading the riders to spend more time riding DH at high speeds (⁵⁵). Mountain bike terrain parks have become a common location for MTB injuries where the overall acute injury rate for recreational mountain bikers is reported to be as high as 15 in 1000 exposures with 87% of injured riders being male (¹). During the 2009 biking season in a MBTP, 86% of injury visits to a local emergency center were male, and 52% of cases were visited between 1 p.m. and 4 p.m. (⁵). Upper-extremity fractures consisted 74.2% of all fractures, and 11.2% of all patients had traumatic brain injury. Almost 9% of patients required transfer to a higher-level trauma center (⁵).
• Predictive factors for increased risk of MTB crashes include prior history of crashing, riding in the dark or in a group (⁶⁰). Riding errors, trail conditions, obstacles, fatigue, and poor weather also are among the most commonly cited causes of injury (¹⁰). Riding DH, at higher speeds and competing in MTB races also are reported as predisposing factors (^36,38). For recreational riders in MBTPs, riding unfamiliar bicycles and being faster than usual can be regarded as injury risk factors, while jumping, using safety equipment other than helmets, and using a new bike increase the risk of hospitalization due to trauma (⁵⁵).

IMO these patterns show two things.

First, clipless pedals and the “sit and spin” mentality are leading to a much higher rate of injuries than needed. Clipless pedals contribute to the severity of OTB crashes and increase the chances of incurring head and spinal injuries while also contributing to overuse injuries from poor foot support. Sitting down more than necessary - especially during High Tension Efforts - leads to overuse injuries, especially in the groin area. By using flat pedals and standing up more to ride you will help to avoid some of the most common injury patterns seen in mountain bikers.

Second, it also speaks to how dangerous it is for the industry to promote our sport - especially the DH/ Bike Park  and even the Enduro scene - to people who aren’t ready for it and to not speak about the real dangers of riding and the need to be physically and technically proficient.

I know that these lessons probably aren’t going to be popular with the mainstream mountain biking world but hopefully they can help you avoid the problems that plague so many riders. Not all injuries are avoidable but by doing what you can to address the most common ones you can stack the odds in your favor.

Until next time…

Ride Strong,

James Wilson