Cycling Injuries: Crashes, Overuse, Helmets and Bike Fit

This article contains affiliate links: if you buy through them we may earn a commission, at no extra cost to you. Learn more.

Sunday group ride, 40 miles in, everyone on the wheel in front. Someone touches a wheel, a bike goes sideways, and three riders hit the road. One stands up and checks the bike. One sits on the curb holding his shoulder, arm tight to his chest. And the third is fine, she says, though she can’t remember the last mile. Cycling injuries come in two kinds: the sudden ones from a crash, and the slow ones that build up over thousands of pedal strokes, like a sore knee, an aching back or numb hands. This page covers both, for every rider from kids and high school mountain bikers to racers, pros and weekend riders.

This page is general information, not medical advice. If you’re hurt, see a sports medicine doctor, physical therapist (PT) or certified athletic trainer (AT). For the bigger picture of the sport, start at our cycling hub.

Crash injuries

On the road, the biggest danger is traffic. US traffic data from the National Highway Traffic Safety Administration (NHTSA) counted 1,166 cyclists killed and an estimated 49,989 injured in traffic crashes in 2023, and the average age of the cyclists killed was 48. That’s why helmets, lights and route choice matter.

Broken collarbone

The classic cycling fracture. The American Academy of Orthopaedic Surgeons (AAOS) explains that most collarbone (clavicle) fractures happen in a fall onto the shoulder or an outstretched arm, and names bicycle accidents among the higher-energy causes. Signs include strong pain, a shoulder that sags down and forward, and trouble lifting the arm. Many heal in a sling; some, where the bone ends move far apart, need surgery. Either way, it needs a doctor and an X-ray. Don’t try to ride home on it.

Road rash

Sliding on asphalt scrapes away layers of skin, usually on the hip, elbow, shoulder and knee. The American Academy of Dermatology’s wound-care advice: gently wash the area with mild soap and water to remove dirt, keep it moist with petroleum jelly, cover it with a bandage and change the bandage daily. Once healed, sunscreen helps the scar fade. See a doctor if the wound is deep, very painful, full of grit you can’t clean out, or shows signs of infection (spreading redness, warmth, pus, fever), and check that your tetanus shot is up to date.

Head injuries, concussion and helmets

Recognize it and stop riding

The CDC’s HEADS UP program is clear for every sport: if you suspect a concussion, stop the activity for the rest of the day and until a health care provider says it’s OK. British Cycling’s concussion guidance uses the same line, “if in doubt, sit them out”, and adds that a rider with a suspected concussion should not ride again the same day, drive, or drink alcohol.

Signs to watch for (CDC): looking dazed or confused, slow answers, clumsiness, memory gaps about the crash, mood changes, vomiting. Riders may report headache, dizziness, nausea, blurry vision or feeling foggy. Call 911 or go to the emergency department for the CDC’s danger signs: one pupil larger than the other, a headache that gets worse, slurred speech, weakness or numbness, repeated vomiting, seizures, growing confusion or drowsiness, or loss of consciousness. After a hard crash, also think about the neck: if a rider has neck pain or tingling in the arms or legs, don’t move them; call for help.

Coming back. The CDC describes a gradual return in steps, moving on only without new symptoms. The 2022 Amsterdam international consensus on concussion in sport recommends only relative rest for the first 24–48 hours, then light activity, with each return-to-sport step usually taking at least 24 hours. In elite racing, the UCI (cycling’s world governing body) recommends at least 6 days away from competition after a concussion; a 2023 study of British Cycling athletes found a median of 16 days out, and its authors argued the minimum should be longer. Your provider sets your timeline.

What helmets do, and how to pick one

The largest review of the research, a 2017 meta-analysis of 55 studies and over 64,000 injured cyclists, found that helmet use was linked to about half the odds of head injury, about 69% lower odds of serious head injury, and 65% lower odds of fatal head injury. The American Academy of Pediatrics (AAP), in its 2022 report on helmets, says they significantly cut the risk of fatal and nonfatal head injury, with the strongest evidence in cycling and snow sports.

• Look for the CPSC label. Every bike helmet sold in the US must meet the Consumer Product Safety Commission standard, which tests impact protection and chin-strap strength, and requires extra coverage for kids up to age 5.
• Racing requires one. USA Cycling requires a securely fastened, approved helmet at all times at any event it permits, club rides included, and full-face helmets for mountain bike downhill.
• Replace it after a crash. The CPSC standard requires a label warning that a helmet that has taken an impact may be damaged in ways you can’t see, and should be destroyed and replaced (or returned to the maker for inspection).
• Fit it right: level on the head, low on the forehead, straps snug.

Many road riders choose a helmet with MIPS, a low-friction layer that the maker says is designed to reduce rotational motion in angled impacts. The Giro Syntax MIPS is a popular, well-vented road helmet that Consumer Reports rated “very good” for impact absorption. For traffic, a rear radar light like the Garmin Varia RTL515 warns you of cars approaching from behind (up to about 140 meters, Garmin says) and doubles as a daytime-visible tail light.

Overuse injuries: knee, back, neck and hands

At a steady 85 pedal revolutions a minute, a rider turns the cranks about 5,000 times an hour. Small problems in position add up. In a study of 109 professional road cyclists from seven teams, low back pain was the most common overuse problem (45% of all overuse injuries), followed by the knee (23%). Over half the riders (58%) had low back pain in the past year, and 41% had seen someone about it. Knee problems were the ones most likely to stop them training or racing.

Knee pain

Pain at the front of the knee, around or behind the kneecap, is the most common cycling knee complaint. A 2011 review of saddle-height research notes that overuse knee pain affects about half of cyclists, and that a small change in saddle height changes knee movement a lot. Its authors suggest setting saddle height so the knee is bent about 25–30 degrees at the bottom of the pedal stroke. Big jumps in mileage, grinding big gears and cleats that twist the foot are other common causes.

Low back and neck pain

Hours bent over the bars load the low back, and holding your head up to see the road loads the neck and shoulders. A reach that is too long or bars that are too low for your flexibility tend to make both worse. Core work, changing position often and a proper fit help many riders. Back pain with numbness or weakness in the legs, or neck pain with tingling into the arms, needs a doctor.

Numb hands

Pressure on the ulnar nerve (“handlebar palsy” or cyclist’s palsy) causes numbness, tingling or weakness in the ring and little fingers, often after several days of long riding; pressure on the median nerve affects the thumb side. Padded gloves, padded bar tape, the right frame size and reach, and moving your hands around the bars every few minutes are the usual fixes. Numbness that lasts after the ride, or any hand weakness, is a reason to see a doctor.

Saddle problems: numbness, saddle sores and chafing

Groin numbness on the bike is common, and it isn’t something to ignore. Research by NIOSH, the CDC’s workplace-safety institute, on bike patrol police officers found that traditional saddles put pressure on the perineum that can lead to genital numbness and, over time, sexual and reproductive health problems; in its studies, no-nose saddles reduced that pressure. If you go numb, try a saddle with a cutout or a different width, check its tilt and height, stand up every so often, and get a fit. For saddle sores and chafing: clean, well-fitting bib shorts worn without underwear, changing right after the ride, and an anti-chafe cream like Chamois Butt’r, which many riders use. A sore that grows, is very painful or doesn’t heal should be seen by a doctor.

Bike fit and prevention

• Get fitted. A professional bike fit (or at least a careful setup) of saddle height, setback, reach, handlebar height and cleat position addresses many knee, back, neck and hand problems at once. Change one thing at a time, in small steps.
• Build volume slowly. The first warm weekend of spring, with a huge ride after a winter off, is a classic setup for knee pain.
• Spin, don’t grind. Easier gears and a higher cadence put less force through the knee on each stroke.
• Strength train off the bike. Hips, core and back support the riding position, and cycling is low-impact, so lifting and some jumping work help bones too (see cycling training).

Gear many riders use for safety and comfort

None of these prevents injuries on its own or replaces a fit or rehab, but they’re in a lot of riders’ kit.

When to see a sports medicine doctor, PT or athletic trainer

• Right away (emergency): any concussion danger sign, neck pain or tingling after a crash, a possible broken bone, a deep or dirty wound.
• Within a day or two: a suspected concussion, a shoulder that sags or won’t lift after a fall, a wrist that stays swollen.
• Soon: knee or back pain that comes back every ride, hand or groin numbness that lasts after riding, a saddle sore that won’t heal.

A sports medicine physician diagnoses and orders imaging; a physical therapist guides rehab and often helps with bike fit; a certified athletic trainer works with school and college teams. Ease back in with our cycling recovery page, and see soccer injuries for more on concussion in team sports.

Cycling injuries: FAQs

What is the most common cycling injury?

It depends on the kind. From crashes: scrapes (road rash), collarbone and wrist fractures, and head injuries. From overuse: low back pain and knee pain. In a study of professional road cyclists, low back pain made up 45% of overuse injuries and the knee 23%.

Do I need a new helmet after a crash?

Yes, if your head hit the ground. The CPSC standard requires helmets to carry a warning that impact damage may not be visible and that a helmet that has taken a hit should be destroyed and replaced or sent back to the maker for inspection.

Why do my knees hurt after cycling?

Common causes are a saddle that’s too low or too high, cleats that twist your foot, pushing big gears, and adding miles too fast. A 2011 research review suggests a saddle height with the knee bent about 25–30 degrees at the bottom of the stroke. If pain keeps coming back, see a PT or get a professional bike fit.

When can I ride again after a concussion?

Not the same day, and only after a health care provider clears you. Return happens in gradual steps, each usually at least 24 hours, moving on only without symptoms. Elite riders are held out at least 6 days under UCI guidance, and many take longer.