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Nerve Injuries in Nerve Injuries in

CyclistsCyclists

Alison Brooks MD MPHAlison Brooks MD MPH

UW Cycling SymposiumUW Cycling Symposium

March 3, 2009March 3, 2009

“Compressions of a Cyclist”“Compressions of a Cyclist”“Compressions of a Cyclist”“Compressions of a Cyclist”“Compressions of a Cyclist”“Compressions of a Cyclist”“Compressions of a Cyclist”“Compressions of a Cyclist”

OverviewOverview

�� Nerve Injury 101Nerve Injury 101

3 points of contacts3 points of contacts

�� Ulnar neuropathy (handlebar)Ulnar neuropathy (handlebar)

�� Pudendal neuropathy (saddle)Pudendal neuropathy (saddle)

•• Erectile dysfunctionErectile dysfunction

�� Foot paresthesias (pedal)Foot paresthesias (pedal)

Nerve InjuryNerve Injury

�� Neuropathy Neuropathy : deranged function and structure of : deranged function and structure of

peripheral nervesperipheral nerves

�� Sensory: touch, pain, temperatureSensory: touch, pain, temperature

�� Motor: muscle contractionMotor: muscle contraction

�� MechanismMechanism

•• Compression (ischemia)*Compression (ischemia)*

•• StretchStretch

Nerve InjuryNerve Injury

�� Nerve contains neurons and blood vessels Nerve contains neurons and blood vessels

�� Susceptible to compressionSusceptible to compression

�� Pressure levelPressure level

�� DurationDuration

Nerve InjuryNerve Injury

�� Nerve intact but not functionalNerve intact but not functional

�� Mildest form of injuryMildest form of injury

�� Focal demyelinationFocal demyelination

�� Impaired conductionImpaired conduction

•• Paralysis of body partParalysis of body part

•• Sensory deficitsSensory deficits

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Nerve InjuryNerve Injury

�� Variable rate of recoveryVariable rate of recovery

�� Amount and duration of compression (ischemia) Amount and duration of compression (ischemia) determine degree of injurydetermine degree of injury

�� Remyelination must occurRemyelination must occur

��Hours to weeks to months (12 weeks)Hours to weeks to months (12 weeks)

��No ongoing compressionNo ongoing compression

UlnarUlnar NeuropathyNeuropathy

Ulnar NeuropathyUlnar Neuropathy

�� “Cyclists’ or handlebar palsy”“Cyclists’ or handlebar palsy”

�� Prolonged grip pressure or Prolonged grip pressure or wrist hyperextensionwrist hyperextension

�� *Sensory*Sensory: numbness/tingling : numbness/tingling

in ring, little fingerin ring, little finger

�� MotorMotor: weakness in hand: weakness in hand

UlnarUlnar NeuropathyNeuropathy

�� NNerve compression at wristerve compression at wrist

�� Deep and superficial branchesDeep and superficial branches

Ulnar NeuropathyUlnar Neuropathy

�� Bicycle fit: wrist positionBicycle fit: wrist position

•• Avoid hyperextensionAvoid hyperextension

•• Less weight on handlebarsLess weight on handlebars

�� Padded gloves and handlebar tapePadded gloves and handlebar tape

�� Change hand position frequentlyChange hand position frequently

Median NeuropathyMedian Neuropathy

�� Less commonLess common

�� Carpal TunnelCarpal Tunnel

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PudendalPudendal NeuropathyNeuropathy

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PudendalPudendal ((BikeseatBikeseat) Neuropathy) Neuropathy

�� Neurovascular compressionNeurovascular compression

�� Between saddle and pubic symphysis (3)Between saddle and pubic symphysis (3)

�� Perineal or genital numbnessPerineal or genital numbness

�� Women also affectedWomen also affected

Erectile Dysfunction

�� 1997 Bicycling Magazine article1997 Bicycling Magazine article

•• >100,000 permanent ED from cycling>100,000 permanent ED from cycling

�� Irwin Goldstein, MD: Irwin Goldstein, MD:

•• “I“I cannot say that sitting on a bicycle seat cannot say that sitting on a bicycle seat

causes impotence. I can’t claim that longcauses impotence. I can’t claim that long--term term

compression causescompression causes impotency.”impotency.”

•• “There are two kinds“There are two kinds of cyclists: Those who are of cyclists: Those who are

impotent and those who will be.”impotent and those who will be.”

Erectile Dysfunction

�� Hippocrates (400 B.C.)Hippocrates (400 B.C.)

�� Scythians north of Black SeaScythians north of Black Sea

�� Nomadic horse peopleNomadic horse people

�� ED in wealthy with horsesED in wealthy with horses

�� “the constant jolting on their “the constant jolting on their

horses unfits them for intercourse”horses unfits them for intercourse”

Erectile DysfunctionErectile Dysfunction

�� Taylor 2004Taylor 2004

�� Surveyed 688 cyclists, 18Surveyed 688 cyclists, 18--77 years77 years

�� ED in younger and older cyclists ED in younger and older cyclists

�� ED prevalence by age group same as gen popnED prevalence by age group same as gen popn

�� No ↑ prevalence in cyclistsNo ↑ prevalence in cyclists

�� No association with cycling variablesNo association with cycling variables

�� Only risk factor was ageOnly risk factor was age

Erectile Dysfunction

�� Sommer 2001Sommer 2001

�� 40 men, measured tpO40 men, measured tpO22, seated, standing, seated, standing

�� Seated cycling decreased tpOSeated cycling decreased tpO22 by twoby two--thirdsthirds

�� Interviewed 100 male cyclistsInterviewed 100 male cyclists

�� 61% reported genital numbness, 17% ED61% reported genital numbness, 17% ED

�� No case of ED without genital numbness but + No case of ED without genital numbness but + numbness without EDnumbness without ED

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Erectile Dysfunction

�� Schwarzer 2002Schwarzer 2002

�� Wider saddle and absent nose protects penile Wider saddle and absent nose protects penile blood flowblood flow

PerinealPerineal PressurePressure

�� Affected by width/shape of rear, nose of saddleAffected by width/shape of rear, nose of saddle

�� Standing vs upright vs racing positionStanding vs upright vs racing position

�� ↑ pressure can reduce penile blood flow↑ pressure can reduce penile blood flow

�� Heavier riders ?Heavier riders ?

�� Handlebar pressure, stability, handling ?Handlebar pressure, stability, handling ?

Erectile Dysfunction

�� Perineal pressure affects penile blood flowPerineal pressure affects penile blood flow

�� Hypoxemia of penis associated penile fibrosisHypoxemia of penis associated penile fibrosis

�� Unclear relationship: numbness ~ EDUnclear relationship: numbness ~ ED

�� Case reportsCase reports

�� No large scale trialsNo large scale trials

��Link between cycling and ED controversialLink between cycling and ED controversial

Pudendal NeuropathyPudendal Neuropathy

�� Bike fitBike fit

•• Saddle angleSaddle angle

•• Saddle heightSaddle height

�� Design of saddleDesign of saddle

•• Wider, padded, flexible nose, cutoutWider, padded, flexible nose, cutout

�� Out of saddle (20Out of saddle (20--30 sec/10 min)30 sec/10 min)

�� Padded shortsPadded shorts

�� ShortShort--term cessation (3term cessation (3--10d)10d)

Foot ParesthesiasFoot Paresthesias

�� Plantar forefoot numb, “hot” or painfulPlantar forefoot numb, “hot” or painful

�� Interdigital nerves compressed by metatarsal Interdigital nerves compressed by metatarsal headsheads

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Foot Paresthesias

�� Less pedal pressureLess pedal pressure

�� Cleat positionCleat position

�� Pedal platformPedal platform

�� Shoe tightnessShoe tightness

�� Shoe soleShoe sole

•• FirmnessFirmness

•• WornWorn

�� Arch support, metatarsal buttonArch support, metatarsal button

SummarySummary

�� Nerve injury affects sensory +/Nerve injury affects sensory +/-- motormotor

�� Degree of injury: amount, durationDegree of injury: amount, duration

�� Nerve must regenerate (up to 12 weeks)Nerve must regenerate (up to 12 weeks)

�� No ongoing compressionNo ongoing compression

�� Check bike fit first (saddle height, position)Check bike fit first (saddle height, position)

�� Equipment changesEquipment changes

�� Controversial link between ED ~ cyclingControversial link between ED ~ cycling

References

�� Mellion MB. Common Cycling Injuries: Management and Prevention. Sports Mellion MB. Common Cycling Injuries: Management and Prevention. Sports Med 1991; 11(1): 52Med 1991; 11(1): 52--7070

�� Sanner WH and O’Halloran WD. The Biomechanics, Etiology, and Sanner WH and O’Halloran WD. The Biomechanics, Etiology, and Treatment of Cycling Injuries. J Am Podiatr Med Assoc 2000; 90(7):354Treatment of Cycling Injuries. J Am Podiatr Med Assoc 2000; 90(7):354--376376

�� Kennedy J. Neurologic Injuries in Cycling and Bike Riding 2008; 26:271Kennedy J. Neurologic Injuries in Cycling and Bike Riding 2008; 26:271--279279

�� Silberman MR e al. Road Bicycle Fit. Clin J Sport Med 2005; 15(4): 271Silberman MR e al. Road Bicycle Fit. Clin J Sport Med 2005; 15(4): 271--276276

�� Asplund C et al. Genitourinary Problems in Bicyclists. Curr Sports Med Rep Asplund C et al. Genitourinary Problems in Bicyclists. Curr Sports Med Rep 2007; 6:3332007; 6:333--339339

�� Campbell WW. Evaluation and Management of Peripheral Nerve Injury. Clin Campbell WW. Evaluation and Management of Peripheral Nerve Injury. Clin Neurophysiology, 2008; 119:1951Neurophysiology, 2008; 119:1951--19651965

�� Taylor JA et al. Bicycle Riding and Its Relationship to the Development of Taylor JA et al. Bicycle Riding and Its Relationship to the Development of Erectile Dysfunction. J Urology 2004; 172:1028Erectile Dysfunction. J Urology 2004; 172:1028--10311031

�� Sommer F. et al. Impotence and Genital Numbness in Cyclists. Int J Sports Sommer F. et al. Impotence and Genital Numbness in Cyclists. Int J Sports Med 2001; 22:410Med 2001; 22:410--413413

�� Schwarzer U et al. Cycling and Penile Oxygen Pressure: the type of Saddle Schwarzer U et al. Cycling and Penile Oxygen Pressure: the type of Saddle Matters. Europ Urology 2002; 41:139Matters. Europ Urology 2002; 41:139--143143

References

� Andy Pruit’s Complete Medical Guide for

Cyclists, Velopress 2006

Questions ?