Mountain Biking Injuries 2 (FR) Bicycles Have Some- (XC) Bicycles Are Relatively Light Freeride On-The-Site and Clinical Management Overuse Injuries (13)
Total Page：16
File Type：pdf, Size：1020Kb
COMPETITIVE SPORTS Mountain Biking Injuries 07/06/2019 on BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3Le0ic6pTQVA6uok+T1gQk2DOuVs2UQ+FWIjZcvNMoLSN+519DE4z8g== by https://journals.lww.com/acsm-csmr from Downloaded Majid Ansari, MD1; Ruhollah Nourian,MD1; and Morteza Khodaee, MD, MPH, FACSM2 Downloaded from https://journals.lww.com/acsm-csmr overuse injuries (13). Such injuries are Abstract reported in 45% to 90% of mountain With the increasing popularity of mountain biking, also known as off-road bikers (13). Injury-related cost of care cycling, and the riders pushing the sport into extremes, there has been a for the cyclists can be a significant finan- corresponding increase in injury. Almost two thirds of acute injuries in- cial burden for cyclists and health care in volve the upper extremities, and a similar proportion of overuse injuries general (46). However, the potential risks affect the lower extremities. Mountain biking appears to be a high-risk by of cycling are outweighed by the health- BhDMf5ePHKav1zEoum1tQfN4a+kJLhEZgbsIHo4XMi0hCywCX1AWnYQp/IlQrHD3Le0ic6pTQVA6uok+T1gQk2DOuVs2UQ+FWIjZcvNMoLSN+519DE4z8g== sport for severe spine injuries. New trends of injury patterns are observed related benefits of riding a bike. with popularity of mountain bike trail parks and freeride cycling. Using On-the-site and clinical management protective gear, improving technical proficiency, and physical fitness may plans for MTB injuries depend on the somewhat decrease the risk of injuries. Simple modifications in bicycle- knowledge of the sport, understanding rider interface areas and with the bicycle (bike fit) also may decrease some the injury mechanism, and precipitating overuse injuries. Bike fit provides the clinician with postural correction factors. Prevention of MTB injuries en- during the sport. In this review, we also discuss the importance of race- tails recognition of both traumatic and day management strategies and monitoring the injury trends. overuse mechanisms (34). There is a pau- city of high-quality evidence with re- gard to sport-specific pathogenesis, treatment, and prevention of the most common overuse MTB Introduction injuries. We present a brief introduction to common inju- With the boom of outdoor activities in the United States, ries and illnesses associated with MTB. the popularity of mountain biking (MTB), also known as off- road cycling, has followed the trend (23). In the United States, the number of mountain bikers has increased from 6.75 mil- Bicycle Types lion in 2006 to 8.32 million in 2015 (23). Despite the increase The bicycles enable the rider to navigate thru terrains, such in popularity of the sport, the reported national frequency of as footpaths, single-tracks, forest, unconventional urban, and acute injuries appears to be decreasing in the United States, mountainous area. The slippery and uneven surface of these conflicting the local patterns of injury frequency (35). With routes usually consists of rocks, mud, dirt, and tree roots. almost a third of injuries occurring during the race, MTB is There is no uniform definition for bicycle types used in MTB. among the sports leading to high overall injury rates in Olympic In this article, we will discuss injuries related to the following sports (20). During the 2012 Summer Olympics, 21% of bicycles: 1) Cross-country (XC) bicycles are relatively light mountain bikers reported acute or overuse injuries, half of which weight bicycles suitable for ascending and descending single- had led the cyclists to lose at least one training/race day (20). tracks or footpaths for long durations of time; 2) Downhill Fifty percent of recreational bikers and 80% of professional (DH) bicycles have stronger components and with the rider in on a more upright position, enable them to make rapid descents 07/06/2019 mountain bikers have reported at least one major severe injury directly related to the sport (35). Microtraumatization from difficult terrains; 3) Freeride (FR) bicycles have some- of contact and noncontact areas due to repetitive forces and what similar geometry and components to DH bicycles which vibration, in addition to fatigue, renders the rider vulnerable to enable the riders to ascend various tracks, in addition to technical stunts and rapid descends in any challenging terrain 1Sports Medicine Research Center, Tehran University of Medical Sciences, (Table 1). The FR bicycles have a shorter wheelbase in Tehran, Iran; and 2Department of Family Medicine, University of Colorado contrast to DH bicycles (Fig. 1). School of Medicine, AFW Clinic, Denver, CO Address for correspondence: Morteza Khodaee, MD, MPH, FACSM, Bike Fit Department of Family Medicine, University of Colorado School of Medicine, Bike fit is the process of making the cyclist and bicycle AFW Clinic, 3055 Roslyn St., Denver, CO 80238; E-mail: geometry compatible to minimize the risk of injury and im- [email protected]. prove the performance at the same time (34,53). Improper 1537-890X/1606/404Y412 bike fit is a precipitating factor for many overuse injuries. Current Sports Medicine Reports However, most studies on bike fit have addressed the cyclists’ Copyright * 2017 by the American College of Sports Medicine performance rather than its effect on biomechanics and 404 Volume 16 & Number 6 & November/December 2017 Mountain Biking Injuries Copyright © 2017 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited. Table 1. 10- change in knee flexion. A knee flexion angle of 25- to 30- Average characteristics of common off-road bicycles. appears to be suitable for manual (static) bike fit methods, - - Fork while the value is 30 to 40 for most motion-capture Wheel Size Travel Rear HTA STA Weight methods (52). Calibrating the process with knee angle mea- Discipline (inches) (mm) Suspension (-) (-) (kg) surement during standing might lead to better accuracy for a the latter method and minimize the observed difference (52). XC 26 , 27.5, 29 100 Yes/No 68-73 72-75 8-10 After adjusting the seat height, fine-tuning the process to FR 26, 27.5, 29a 175 Yes 63-65 74-76 14-17 prevent excessive pelvic sway in frontal plane also has been DH 26, 27.5, 29a 200 Yes 63-64 57-60 15-18 advocated (41). Saddle height determination based on leg length alone may be inaccurate (17). a Currently less common variants. HTA, head tube angle; STA, seat tube angle. Saddle Setback Fore/aft positioning of the saddle also affects the kine- injuries (17). Traditionally, after goal-setting with the rider, matics of the knee joint (19). The Knee Over Pedal Spindle the bike fit starts with obtaining a medical history and physical (KOPS) rule might be helpful in most of the cases. After examination with special emphasis on spine and lower-extremity early saddle height adjustment, a plumb-line anterior to the problems. Afterward, on-the-bike-fit begins with stepwise modi- knee should cross the center of the pedal axis with cranks in fications in bike-rider interface. Then, the degree of trunk incli- horizontal position. For most of the bicycles with conven- nation, position of the shoulders, and cervical spine ergonomics tional seat tube axis, this adjustment will place the greater are noted (34). The pedals, shoes, saddle type, height, and tilt, trochanter in alignment with the seat-tube (Fig. 1). crank size, handlebar type and width, headset height, stem length and inclination might be adjusted or modified (Table 2) The Foot-Shoe-Pedal Interface (13,17,19,62). Applying the motion-capture technology, Frontal plane suboptimal moments in lower extremities 2- and 3-dimensional kinematic modelings have become avail- (including knee varus or valgus, and tibial rotational forces) able in addition to more traditional techniques with no proven have been suggested as precipitating factors for chronic knee superiority between the methods with regard to injury or problems in cyclists (22). Various insoles and wedges are used performance or comfort (34). for cyclists to address these problems, with no significant ef- fect on performance (22). Varus wedges may be beneficial for Saddle Height cyclists with forefoot varus deformity, while forefoot inversion An increase in knee flexion during cycling (e.g., due to low wedges may be beneficial for riders with foot pronation (17). saddle height) is correlated with patellofemoral pain syn- Changing the Q-Factor (interpedal stance width) also is an drome (PFPS), while decreased knee flexion (e.g., due to ex- easily performed, but not free of limitations, method of cessive saddle height) has been linked to hamstring injuries (52). changing frontal plane kinematics (22). Cleat rotation (float) One of the common methods to determine the saddle adjustment also might help cyclists with meniscal and height is the knee flexion measurement when the pedal is at intra-articular knee problems (22). the lowermost position (52). Changes in neuromuscular ac- tivation patterns after altering the saddle height have been Acute Injuries observed in gastrosoleus, quadriceps, and hamstring muscles, The most common mechanism of acute severe injury for with lowered seat reducing the activity of gastrosoleus and competitive mountain bikers has been falling forward (64.9%), hamstring, and increasing the activity of quadriceps (53). A and 85.6% of such injuries have occurred while riding DH (14). change of 2.6 to 2.9 cm in saddle height corresponds to about Falling forward had led to a significantly higher Injury Figure 1: Schematic bicycle diagram.