Editing Cycling (section)

==Bicycle safety==

{{Further|Bicycle safety}}
[[File:Santa-Maria-Patroness-of-bicyclists-4606.jpg|thumb|[[Virgin Mary]] venerated as the holy protector of bicyclists on the roads of the mountainous [[Basque Country (autonomous community)|Basque Country]]|alt=A statue, covered with flowers.]]
Cycling suffers from a perception that it is unsafe.<ref>{{cite book |title=On Your Bike! |first=Matt |last=Seaton |page=103 |year=2006 |publisher=[[Black Dog Publishing]] |location=London |isbn=978-1-904772-40-8}}</ref><ref>Horton, D. (2007) Fear of Cycling. In p. Rosen, P. Cox, Horton, D. Cycling and Society. London: Ashgate</ref> This perception is not always backed by hard numbers, because of under reporting of crashes and lack of bicycle use data (amount of cycling, kilometers cycled) which make it hard to assess the [[risk]] and monitor changes in risks.<ref name="Vanparijs">{{cite journal |last1=Vanparijs |first1=J |title=Exposure measurement in bicycle safety analysis: A review of the literature |journal=Accident Analysis & Prevention |volume=84 |pages=9–19 |date=August 2015 |url=https://www.researchgate.net/publication/281166893 |doi=10.1016/j.aap.2015.08.007 |pmid=26296182 |last2=Int Panis |first2=L |last3=Meeusen |first3=R |last4=De Geus |first4=B}}</ref>
In the UK, fatality rates per mile or kilometre are slightly less than those for walking.<ref name="UK fatalities by mode">{{cite web |url=http://www.dft.gov.uk/adobepdf/162469/221412/221549/227755/rcgb2007.pdf |title=Road Casualties Great Britain 2007&nbsp;– Annual Report (page 82, "Fatality rates by mode of travel") |publisher=Department for Transport |archive-url=https://web.archive.org/web/20090411070127/http://www.dft.gov.uk/adobepdf/162469/221412/221549/227755/rcgb2007.pdf |archive-date=11 April 2009 |url-status=dead}}</ref> In the US, bicycling fatality rates are less than 2/3 of those walking the same distance.<ref>{{cite web |url=http://www.bts.gov/publications/transportation_statistics_annual_report/2004/html/chapter_02/daily_travel_by_walking_and_bicycling.html |title=Daily Travel by Walking and Bicycling |publisher=Bureau of Transportation Statistics |access-date=29 September 2009 |archive-url=https://web.archive.org/web/20090710034644/http://www.bts.gov/publications/transportation_statistics_annual_report/2004/html/chapter_02/daily_travel_by_walking_and_bicycling.html |archive-date=10 July 2009 |url-status=dead}}</ref><ref>{{cite web |url=http://www-fars.nhtsa.dot.gov/ |title=Fatality Analysis Reporting System |publisher=National Highway Traffic Safety Administration |access-date=29 September 2009 |archive-url=https://web.archive.org/web/20081119122727/http://www-fars.nhtsa.dot.gov./ |archive-date=19 November 2008 |url-status=dead}}</ref> However, in the UK for example the fatality and serious injury rates ''per hour of travel'' are just over double for cycling than those for walking.<ref name="UK fatalities by mode" />

Despite the risk factors associated with bicycling, cyclists have a lower overall mortality rate when compared to other groups. A Danish study in 2000 found that even after adjustment for other risk factors, including leisure time physical activity, those who did not cycle to work experienced a 39% higher mortality rate than those who did.<ref>{{cite journal |doi=10.1001/archinte.160.11.1621 |pmid=10847255 |title=All-Cause Mortality Associated with Physical Activity During Leisure Time, Work, Sports, and Cycling to Work |journal=Archives of Internal Medicine |volume=160 |issue=11 |pages=1621–8 |year=2000 |last1=Andersen |first1=Lars Bo |last2=Schnohr |first2=Peter |last3=Schroll |first3=Marianne |last4=Hein |first4=Hans Ole |doi-access=free}}</ref>

Injuries (to cyclists, from cycling) can be divided into two types:
* [[Physical trauma]] (extrinsic)
* Overuse (intrinsic)

===Physical trauma===
[[Acute (medical)|Acute]] physical trauma includes injuries to the head and extremities resulting from falls and collisions.{{citation needed|date=July 2022}} Most cycle deaths result from a collision with a car or heavy goods vehicle. Drivers are at fault in the majority of these crashes.<ref>{{cite journal |last1=Bíl |first1=Michal |last2=Bílová |first2=Martina |last3=Dobiáš |first3=Martin |last4=Andrášik |first4=Richard |title=Circumstances and causes of fatal cycling crashes in the Czech Republic |journal=Traffic Injury Prevention |date=2016 |volume=17 |issue=4 |pages=394–399 |doi=10.1080/15389588.2015.1094183 |pmid=26507371 |s2cid=1848346 |quote=The driver was the guilty party in 57 cases (68.7%) and the cyclist in the remaining 26 cases (31.3%).}}</ref><ref>{{cite news |last1=Chambers |first1=Peter |last2=Andrews |first2=Tom |title=Rising cyclist death toll is mainly due to drivers, so change the road laws and culture |url=https://theconversation.com/rising-cyclist-death-toll-is-mainly-due-to-drivers-so-change-the-road-laws-and-culture-102567 |access-date=10 July 2022 |work=The Conversation |language=en |quote=In Australia, drivers are to blame for at least 79% of accidents with cyclists.}}</ref><ref>{{cite news |url=https://www.mcclatchydc.com/news/politics-government/congress/article237028854.html |title=Most bike crashes involve drivers overtaking cyclists |access-date=10 July 2022}}</ref><ref>{{cite news |title=Risky cycling rarely to blame for bike accidents, study finds |url=https://www.theguardian.com/lifeandstyle/2009/dec/15/cycling-bike-accidents-study |access-date=10 July 2022 |work=the Guardian |date=15 December 2009 |language=en}}</ref><ref>{{cite journal |last1=Glász |first1=Attila |last2=Juhász |first2=János |title=Car-pedestrian and car-cyclist accidents in Hungary |journal=Transportation Research Procedia |date=2017 |volume=24 |pages=474–481 |doi=10.1016/j.trpro.2017.05.085 |s2cid=114731588 |language=en |issn=2352-1465 |quote=The suspected primary reason of car-cyclist accidents was almost exclusively the driver's fault, in a total of 7,889 cases (99.6%), therefore we did not detail the accident numbers belonging to other reasons individually. |doi-access=free}}</ref> Segregated cycling infrastructure reduces the rate of crashes between bicycles and motor vehicles.<ref>{{cite journal |last1=Marshall |first1=Wesley E. |last2=Ferenchak |first2=Nicholas N. |title=Why cities with high bicycling rates are safer for all road users |journal=Journal of Transport & Health |date=2019 |volume=13 |pages=100539 |doi=10.1016/j.jth.2019.03.004 |bibcode=2019JTHea..1300539M |s2cid=191824684 |url=https://www.sciencedirect.com/science/article/abs/pii/S2214140518301488 |language=en |issn=2214-1405}}</ref>

Although a majority of bicycle collisions occur during the day,<ref name="ROSPA">{{cite web |url=http://www.rospa.com/road-safety/advice/pedal-cyclists/facts-figures/ |title=Cycling Accidents Facts & Figures – August 2014 |access-date=26 November 2016 |website=www.rospa.com |publisher=The Royal Society for the Prevention of Accidents |archive-url=https://web.archive.org/web/20161126064112/http://www.rospa.com/road-safety/advice/pedal-cyclists/facts-figures/ |archive-date=26 November 2016 |url-status=dead}}</ref> [[Bicycle lighting#Safety|bicycle lighting]] is recommended for [[bicycle safety|safety when bicycling]] at night to increase visibility.<ref name="NHSTA">{{cite web |url=http://www.nhtsa.gov/staticfiles/nti/pdf/812202-CountermeasuresThatWork8th.pdf |title=National Highway Traffic Safety Administration. Countermeasures that work: A highway safety countermeasures guide for State Highway Safety Offices, 8th edition. |date=2015 |website=www.nhtsa.gov |publisher=National Highway Traffic Safety Administration |access-date=26 November 2016 |archive-url=https://web.archive.org/web/20161209234225/http://www.nhtsa.gov/staticfiles/nti/pdf/812202-CountermeasuresThatWork8th.pdf |archive-date=9 December 2016 |url-status=dead}}</ref>

[[File:Taiwan 2009 HuaLien Taroko Gorge Biking FRD 5416 Pano Extracted.jpg|thumb|Bicyclist pedals uphill at the [[Taroko National Park|Taroko Gorge]] in Taiwan]]
[[File:Bicycles and winter.jpg|thumb|Bicycles in [[Helsinki]] ([[Finland]])]]

===Overuse injuries===
Of a study of 518 cyclists, a large majority reported at least one overuse injury, with over one third requiring medical treatment. The most common injury sites were the neck (48.8%) and the knees (41.7%), as well as the groin/buttocks (36.1%), hands (31.1%), and back (30.3%). Women were more likely to suffer from neck and shoulder pain than men.<ref>{{cite journal |doi=10.1055/s-2007-972992 |pmid=7649713 |title=An Epidemiological Analysis of Overuse Injuries Among Recreational Cyclists |journal=International Journal of Sports Medicine |volume=16 |issue=3 |pages=201–6 |year=2007 |last1=Wilber |first1=C. |last2=Holland |first2=G. |last3=Madison |first3=R. |last4=Loy |first4=S. |s2cid=8240258}}</ref>

Many cyclists suffer from overuse injuries to the knees, affecting cyclists at all levels. These are caused by many factors:<ref>{{cite news |url=http://www.biomech.com/db_area/archives/1996/9607sports.bio.html |archive-url=https://web.archive.org/web/20070928070212/http://www.biomech.com/db_area/archives/1996/9607sports.bio.html |archive-date=28 September 2007 |title=Knee Pain in Cycling: New Twist on an old Injury |publisher=BioMechanics |date=July–August 1996 |access-date=24 November 2006}}</ref>
*Incorrect bicycle fit or adjustment, particularly the saddle.
*Incorrect adjustment of clipless pedals.
*Too many hills, or too many miles, too early in the training season.
*Poor training preparation for long touring rides.
*Selecting too high a gear. A lower gear for uphill climb protects the knees, even though muscles may be well able to handle a higher gear.

Overuse injuries, including chronic nerve damage at weight bearing locations, can occur as a result of repeatedly riding a bicycle for extended periods of time. Damage to the [[ulnar nerve]] in the palm, [[carpal tunnel syndrome|carpal tunnel]] in the wrist, the genitourinary tract<ref>{{cite journal |doi=10.1016/j.eururo.2004.10.024 |pmid=15716187 |title=The Vicious Cycling: Bicycling Related Urogenital Disorders |journal=European Urology |volume=47 |issue=3 |pages=277–86; discussion 286–7 |year=2005 |last1=Leibovitch |first1=Ilan |last2=Mor |first2=Yoram}}</ref> or [[bicycle seat neuropathy]]<ref>{{cite news |url=http://www.emedicine.com/SPORTS/topic12.htm |title=Bicycle Seat Neuropathy, follow up |publisher=[[eMedicine]] |date=8 February 2006 |access-date=20 March 2006 |archive-url=https://web.archive.org/web/20060217232945/http://www.emedicine.com/sports/topic12.htm |archive-date=17 February 2006 |url-status=dead}}</ref> may result from overuse. [[Recumbent bicycle]]s are designed on different [[ergonomics|ergonomic]] principles and eliminate pressure from the saddle and handlebars, due to the relaxed riding position.

Note that overuse is a relative term, and capacity varies greatly between individuals. Someone starting out in cycling must be careful to increase length and frequency of cycling sessions slowly, starting for example at an hour or two per day, or a hundred miles or kilometers per week. Bilateral muscular pain is a normal by-product of the training process, whereas unilateral pain may reveal "exercise-induced arterial endofibrosis".<ref>{{cite journal |pmid=15233595 |year=2004 |last1=Abraham |first1=P. |title=Past, present and future of arterial endofibrosis in athletes: A point of view |journal=Sports Medicine |volume=34 |issue=7 |pages=419–25 |last2=Bouyé |first2=P |last3=Quéré |first3=I |last4=Chevalier |first4=J. M. |last5=Saumet |first5=J. L. |s2cid=33730384 |doi=10.2165/00007256-200434070-00001}}</ref> Joint pain and numbness are also early signs of overuse injury.

A Spanish study of top [[triathlete]]s found those who cover more than 186 miles (300&nbsp;km) a week on their bikes have less than 4% normal looking [[sperm]], where normal adult males would be expected to have from 15% to 20%.<ref name="bmj.com"/><ref>{{cite news |last=Wilkinson |first=Emma |url=http://news.bbc.co.uk/2/hi/health/8124458.stm |title=BBC: Elite cyclists 'risk infertility' |work=BBC News |date=29 June 2009 |access-date=6 June 2012}}</ref>

===Saddle related===
Much work has been done to investigate optimal [[bicycle saddle]] shape, size and position, and negative effects of extended use of less than optimal seats or configurations.

Excessive saddle height can cause [[Posterior (anatomy)|posterior]] knee pain, while setting the saddle too low can cause pain in the [[anterior]] of the knee. An incorrectly fitted saddle may eventually lead to muscle imbalance. A 25 to 35-degree knee angle is recommended to avoid an overuse injury.<ref>{{cite news |url=http://nationalpti.edu/blog/2015/07/avoiding-repetitive-knee-injuries-while-riding-a-bike/ |title=Avoid Repetitive Knee Injuries While Riding A Bike |access-date=13 July 2015 |archive-url=https://web.archive.org/web/20150713225220/http://nationalpti.edu/blog/2015/07/avoiding-repetitive-knee-injuries-while-riding-a-bike/ |archive-date=13 July 2015 |url-status=dead}}</ref>

Although cycling is beneficial to health, men can be negatively affected by cycling more than three hours a week due to the significant weight on their perineum, an area located between the scrotum and the anus which hold some of the nerves and arteries that pass to the penis.<ref>{{cite web |url=https://www.webmd.com/men/features/biking-and-erectile-dysfunction-a-real-risk |title=Biking and Erectile Dysfunction: A Real Risk? |last=Valeo |first=Tom |date=11 September 2007 |access-date=19 October 2022}}</ref> This weight for continuous hours a week can cause men to experience numbness or tingling which can lead to them losing the ability to achieve an erection due to reduced blood flow; which 13% of males did experience in a study by Norwegian researchers who gathered data from 160 men participating in a long-distance bike tour.<ref>{{cite web |url=https://www.theguardian.com/environment/bike-blog/2018/feb/16/does-cycling-really-damage-mens-sexual-organs |title=Does Cycling Really Damage Men's Sexual Organs? |last=Brown |first=Jessica |website=[[TheGuardian.com]] |date=16 February 2018 |access-date=19 October 2022}}</ref> Fitting a proper sized seat can prevent this effect.<ref name="bmj.com">{{cite journal |doi=10.1136/bmj.g425 |pmid=24524928 |pmc=3923979 |title=Health effects of the London bicycle sharing system: Health impact modelling study |journal=BMJ |volume=348 |pages=g425 |year=2014 |last1=Woodcock |first1=J. |last2=Tainio |first2=M. |last3=Cheshire |first3=J. |last4=O'Brien |first4=O. |last5=Goodman |first5=A.}}</ref><ref>{{cite news |url=http://news.bbc.co.uk/2/hi/health/149268.stm |title=Cycle of despair |work=BBC News |access-date=29 September 2009 |date=12 August 1998}}</ref>{{Unreliable medical source|date=November 2010}}<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/health/363070.stm |title=Cycling linked to impotence |work=BBC News |access-date=29 September 2009 |date=7 June 1999}}</ref><ref name="no nose">{{cite journal |doi=10.1111/j.1743-6109.2008.00867.x |pmid=18466268 |title=Cutting off the Nose to Save the Penis |journal=Journal of Sexual Medicine |volume=5 |issue=8 |pages=1932–40 |year=2008 |last1=Schrader |first1=Steven M. |last2=Breitenstein |first2=Michael J. |last3=Lowe |first3=Brian D.}}</ref> In extreme cases, [[pudendal nerve entrapment]] can be a source of intractable perineal pain.<ref>{{cite journal |doi=10.1097/00002060-200306000-00013 |year=2003 |last1=Ramsden |first1=Christopher |journal=American Journal of Physical Medicine & Rehabilitation |volume=82 |issue=6 |pages=479–484 |last2=McDaniel |first2=Michael |last3=Harmon |first3=Robert |last4=Renney |first4=Kenneth |last5=Faure |first5=Alexis |pmid=12820792 |title=Pudendal nerve entrapment as source of intractable perineal pain}}</ref> Some cyclists with induced pudendal nerve pressure neuropathy gained relief from improvements in saddle position and riding techniques.<ref>{{cite journal |pmid=1821826 |year=1991 |last1=Silbert |first1=P. L. |title=Bicycling induced pudendal nerve pressure neuropathy |journal=Clinical and Experimental Neurology |volume=28 |pages=191–6 |last2=Dunne |first2=J. W. |last3=Edis |first3=R. H. |last4=Stewart-Wynne |first4=E. G.}}</ref>

The [[National Institute for Occupational Safety and Health]] (NIOSH) has investigated the potential health effects of prolonged bicycling in police bicycle patrol units, including the possibility that some bicycle saddles exert excessive pressure on the urogenital area of cyclists, restricting blood flow to the genitals.<ref>{{cite web |url=https://www.cdc.gov/niosh/topics/bike/ |title=NIOSH -Bicycle Saddles and Reproductive Health |access-date=10 October 2007 |publisher=United States National Institute for Occupational Safety and Health}}</ref> Their study found that using bicycle seats without protruding noses reduced pressure on the groin by at least 65% and significantly reduced the number of cases of urogenital paresthesia. A follow-up found that 90% of bicycle officers who tried the no-nose seat were using it six months later. NIOSH recommends that riders use a no-nose bicycle seat for workplace bicycling.<ref name ="no nose" /><ref name="impact niosh">{{cite journal |url=https://www.cdc.gov/niosh/docs/2010-163/ |title=NIOSH Research Demonstrates the Effectiveness of No-Nose Bicycle Seats in Reducing Groin Pressure and Improving Sexual Health (2010-163) |website=CDC – The National Institute for Occupational Safety and Health (NIOSH) |date=October 2010 |doi=10.26616/NIOSHPUB2010163 |doi-access=free}}</ref>

Despite rumors to the contrary, there is no [[scientific evidence]] linking cycling with [[testicular cancer]].<ref>{{cite web |url=http://www.andrologyaustralia.org/library/TesticlarCancerFactSheet.pdf |title=Testiclar Cancer Fact Sheet |access-date=30 September 2008 |publisher=Monash Institute of Medical Research |url-status=dead |archive-url=https://web.archive.org/web/20081003171048/http://www.andrologyaustralia.org/library/TesticlarCancerFactSheet.pdf |archive-date=3 October 2008}}</ref>

===Exposure to air pollution===
One concern is that riding in traffic may expose the cyclist to higher levels of air pollution, especially cyclists regularly traveling on or along busy roads. Some authors have claimed this to be untrue, showing that the pollutant and irritant count within cars is consistently higher,<ref>{{cite journal |doi=10.1071/HE04063 |last1=Chertok |first1=Michael |last2=Voukelatos |first2=Alexander |last3=Sheppeard |first3=Vicky |last4=Rissel |first4=Chris |year=2004 |title=Comparison of air pollution exposure for five commuting modes in Sydney – car, train, bus, bicycle and walking |journal=Health Promotion Journal of Australia |volume=15 |issue=1 |pages=63–7 |url=http://vadebike.org/wp-content/uploads/2008/08/Comparison-of-air-pollution-exposure-for-five-commuting-modes-in-Sydney-car-train-bus-bicycle-and-walking-HPJA.pdf |access-date=1 February 2016 |archive-url=https://web.archive.org/web/20160205085716/http://vadebike.org/wp-content/uploads/2008/08/Comparison-of-air-pollution-exposure-for-five-commuting-modes-in-Sydney-car-train-bus-bicycle-and-walking-HPJA.pdf |archive-date=5 February 2016 |url-status=dead}}</ref> presumably because of limited circulation of air within the car and due to the air intake being directly in the stream of other traffic. Other authors have found small or inconsistent differences in concentrations but claim that exposure of cyclists is higher due to increased minute [[ventilation (physiology)|ventilation]]<ref>{{cite journal |doi=10.1016/j.atmosenv.2010.04.028 |title=Exposure to particulate matter in traffic: A comparison of cyclists and car passengers |journal=Atmospheric Environment |volume=44 |issue=19 |pages=2263–2270 |year=2010 |last1=Int Panis |first1=Luc |last2=De Geus |first2=Bas |last3=Vandenbulcke |first3=Grégory |last4=Willems |first4=Hanny |last5=Degraeuwe |first5=Bart |last6=Bleux |first6=Nico |last7=Mishra |first7=Vinit |last8=Thomas |first8=Isabelle |last9=Meeusen |first9=Romain |bibcode=2010AtmEn..44.2263I |s2cid=56142753}}</ref> and is associated with minor biological changes.<ref>{{cite journal |doi=10.1186/1476-069X-9-64 |pmid=20973949 |pmc=2984475 |title=Subclinical responses in healthy cyclists briefly exposed to traffic-related air pollution: An intervention study |journal=Environmental Health |volume=9 |pages=64 |year=2010 |last1=Jacobs |first1=Lotte |last2=Nawrot |first2=Tim S |last3=De Geus |first3=Bas |last4=Meeusen |first4=Romain |last5=Degraeuwe |first5=Bart |last6=Bernard |first6=Alfred |last7=Sughis |first7=Muhammad |last8=Nemery |first8=Benoit |last9=Panis |first9=Luc |issue=1 |doi-access=free|bibcode=2010EnvHe...9...64J }}</ref> A 2010 study estimated that the gained life expectancy from the health benefits of cycling (approximately 3–14 months gained) greatly exceeded the lost life expectancy from air pollution (approximately 0.8–40 days lost).<ref name=":0" /> However, a systematic review comparing the effects of air pollution exposure on the health of cyclists was conducted, but the authors concluded that the differing methodologies and measuring parameters of each study made it difficult to compare results and suggested a more holistic approach was needed to accomplish this.<ref>{{Cite journal |last1=Raza |first1=Wasif |last2=Forsberg |first2=Bertil |last3=Johansson |first3=Christer |last4=Sommar |first4=Johan Nilsson |date=5 February 2018 |title=Air pollution as a risk factor in health impact assessments of a travel mode shift towards cycling |journal=Global Health Action |volume=11 |issue=1 |pages=1429081 |doi=10.1080/16549716.2018.1429081 |issn=1654-9716 |pmc=5804679 |pmid=29400262}}</ref> The significance of the associated health effect, if any, is unclear but probably much smaller than the health impacts associated with accidents and the health benefits derived from additional physical activity.