WHY DO HANDS GO NUMB?
The hand is traversed by two central nerves, the ulnar nerve and the median nerve. When people talk colloquially about carpal tunnel syndrome, they mean numb or painful hands. However, these problems come from both the median nerve and the ulnar nerve. The ulnar nerve, as you can see in the drawing, leads from the outer ball of the hand to the little and ring finger. It reacts negatively to pressure on the outer ball. Especially with racing bike handlebars, the pressure on the outer ball of the hand and thus on the ulnar nerve is at a maximum. This leads to numbness and weakness of the hand muscles.
A second source of problems is the median nerve. It runs through a narrow tunnel in the wrist, the carpal tunnel. Pressure and bending in this area of the hand lead to the well-known carpal tunnel syndrome.
Carpal tunnel syndrome causes numbness and weakness in the thumb, middle finger and index finger. In severe cases, the numbness does not disappear until long after the bike ride or gets worse overnight because the tissues of the hand tend to swell slightly at night.