Who gets itEmerging evidence
After a 600 kilometre ride, 23 of 25 riders had motor or sensory symptoms in the hands, or both, whatever their experience; mountain bikers had more loss of feeling. In 14 riders, a 6-day, 420-mile tour slowed the deep branch of the ulnar nerve and worsened carpal tunnel syndrome in 3 of 28 hands. Numb hands or fingers were 21.5% of the complaints of 1,505 riders at bike-fit services, and hand complaints 31.1% in a survey of recreational riders.
A review of 13 studies, most of them case reports, rated the evidence low quality and noted that riders often dismiss the symptoms as part of the ride.
Sources 1, 2, 3, 4, 5
Cyclist's palsy: the wrist and the palmEmerging evidence
Cyclist's palsy is often described as pressure on the ulnar nerve in Guyon's canal, a tunnel at the base of the palm on the little-finger side. A 2025 review describes it more widely: a group of ulnar nerve problems at the wrist and in the palm, often affecting only the deep branch that works the small hand muscles. The highest handlebar pressure lies over that branch, beyond the canal, which fits the many cases with weakness rather than numbness.
After the 600 kilometre ride, weakness alone was the commonest pattern (36% of hands), with loss of feeling alone in 10% and both in 24%.
Sources 6, 7, 1
Why it happensEmerging evidence
In 36 experienced riders, the drops gave the highest pressure over the heel of the hand on the little-finger side and the most bent-back wrist. A 2025 review lists the usual risk factors: a jump in riding, a set-up that loads the hands (bars that are low or far away, a saddle tilted nose-down, an aggressive frame), not changing hand position, long spells in the drops, and a past ulnar nerve problem. Rough roads add vibration.
On aero bars the pressure moves to the elbow: in Ironman athletes, signs of ulnar nerve irritation at the elbow became common after rides.
Sources 8, 6, 9
Weakness without numbnessEmerging evidence
The deep branch of the ulnar nerve carries no feeling, so it can be squeezed until the hand muscles weaken with no numbness to warn you. In 3 riders, a severe palsy of the small hand muscles followed riding, and the authors warn that with bar-end grips and downhill riding, where much of your weight rests on the hand, even a single ride may be enough. The 2025 review stresses spotting it early, before a mild nerve injury becomes a more serious one.
Sources 7, 1, 6
When a nerve test or scan helps, and what it changesEmerging evidence
Not for mild symptoms that settle with changes. In a trial of mild ulnar nerve compression at the elbow, 76% of people with typical symptoms had normal nerve tests and 75% of those with abnormal tests improved, so the authors called routine testing unnecessary. For carpal tunnel, the National Health Service (NHS) uses a nerve conduction test or a scan only when the diagnosis isn't clear.
For weakness, wasting or numbness that persists, nerve conduction tests and electromyography (EMG) show which nerve is affected, where and how badly; for riders, a test of the muscle between the thumb and index finger is needed, because routine ulnar tests can miss the deep branch. An ultrasound or magnetic resonance imaging (MRI) scan can look for a cyst: in one case first thought to be at the elbow, MRI found a cyst in Guyon's canal, which was removed. A cyst or other pressing lesion goes to a surgeon; otherwise care stays with position, equipment and riding changes.
Sources 10, 11, 6, 12, 13
How long it lastsEmerging evidence
No study has followed riders over time. A 2025 review says the vast majority recover without surgery. Case reports vary: one rider's clawed hand settled in 5 days while another had recovered only slightly at 5 weeks, one recovered quickly after changing his grip, and one rider who was never given a diagnosis or told the risk of riding on still had loss of feeling 7 years later. For carpal tunnel syndrome, the NHS says it sometimes gets better by itself in a few months.
So numbness that fades within the ride or soon after is a warning to change something today, and numbness or weakness that persists needs checking. No one can promise a date.
Sources 6, 5, 14, 15, 11