Long-distances riders palm neuropraxia (cyclist palsy)
A legend says that at the start of the Tour Divide route, someone has placed a sign saying: "Hey, you are riding the great divide! What do you need your pinky for?"
Well, that may be true for some, but many of us do need the little finger to scratch, pick our noses and in my case, to preform surgeries (the author is a specialist veterinarian orthopedic surgeon). As an ultra-endurance cyclist, I experienced loss of sensation and motor function in my fingers, which almost caused me to retire from competitive riding.
The aim of this short article is to explain why such an injury is so frequent among ultra-endurance riders and propose solutions based on my own and others experience.
Have a look at Figures 1 and 2. Three nerves are controlling the function of our hands: the Median, Ulnar, and Radial nerves. Each of these nerves is responsible for both sensory (feeling) and motor (movement) function in different parts of the hand (Figure 1). The median and ulnar nerves enter the wrist through the Guyon’s Canal and the carpal tunnel respectively. Those are anatomically tight tunnels, located at the base of the palm (Figure 2). When you hold the handlebar tightly for a long period of time, cycling through rough terrain or downhill, the wrist is hyperextended (Figure 3). This position of the wrist causes compression of the carpal tunnel and Guyon’s Canal that stress the Median and Ulnar nerves. The repetitive trauma eventually damages nerve conduction and can cause loss of sensory and motor functions. This results in numbness and paralysis of the associated parts of the palm and fingers.
It seems that among long-distance riders, injury to the ulnar nerve is more common than the median nerve. It also seems that sensory deficits are more common than motor deficits. Therefore, loss of sensation, numbness and tingling in the ulnar territory (ring and pinky fingers) are the most prevalent symptoms. Motor deficits are considered a more severe injury and could be expressed as finger weakness and loss of finesse and accuracy of movement. The professional literature commonly terms this injury the cyclist neuropraxia, cyclist palsy or handlebar palsy, and the injury can take months to recover.
The first time I experienced such an injury was after participating in the Holyland Challenge (HLC) mountain bike competition taking place in Israel. It is a tough race that passes along extensive and technical single tracks. The Israeli desert is packed with stones and rough roads which put significant pressure on the palms. At the end of this race I could not feel my ring and pinky fingers (Impairment of ulnar nerve function). Several months later, I went out for the 750km P2P competition (which also takes place in the Israeli desert). This time in addition to the sensory loss, I also experienced severe weakness of the middle, index and ring fingers (Damage to both the median and ulnar nerves). It took me five months to recover from these injuries, due to damaged nerves recovering very slowly. On a quick survey aimed at members of long-distance cycling groups, it turned out that at least a third experienced palm neuropraxia to some degree.
How to prevent riders palm neuropraxia?
The posture of your body on the bike and bike fit will influence the pressure applied on your hands. A high saddle or low handlebars causing excessive weight forward of the center of gravity of the body, can add pressure on the hands. I assume that most riders that go out for long-distance rides are experienced riders who are well aware of their riding posture, so I will not focus on posture issues. Instead, I will try to examine some of the solutions offered and present some of the solutions I found. Nevertheless, at this point it is important toemphasize that the solution may be individual and what fits one person may not fit the other.
Cushioning the pressure points:
Originally, I thought that padded cycling gloves and soft grips would be good ways to ease the pressure on the palms. I have tried Chunky and Extra Chunky ESI grips combined with highly padded gloves but unfortunately, this did not ease the pinky numbness I experienced. I believe that the reason for failure was that most of the damage was caused by the hyperextension of the wrist (see Figure 3),which can not be prevented by the thick padding.
Changing the grip angle of the handlebars:
The shape of the handlebars dictates the anatomical alignment of the palm and arms. One of the handlebars that offers a more comfortable grip angle is Jones H-Bar® This handlebar, set at 45 degrees sweep, puts your wrists in a natural and relaxed position. I did not try this handlebar but a short survey among riders who used it raised inconsistent conclusions – for some it helped but for others it caused aggravation of symptoms.
Adding additional grip forms to relieve the pressure on the palm:
SPIR grips, bar ends and aerobars give the cyclist an option to change the shape and position of the grip during the ride and relieve the pressure on the palms. For me, the aerobar works very well. At least 15-20% of the ride, I lean forward and rest on the forearm pads, taking the pressure off my hands (Figure 5).
The key point to success: prevent hyperextension of the wrist:
Because hyperextension is the main cause of the cyclist neuropraxia, methods that try to prevent hyperextension have the highest potential of successfully solving this problem.
Some riders reported improvement after using Ergon grips (figure 6). The wing design of Ergon GP grips gives the hand more support and automatically puts the wrist in a more ergonomic position, thus preventing hyperextension of the carpus. For me it did not work and actually worsened the situation after riding 500km. I am not under the impression that the Ergon grips really manage to prevent hyperextension.
The most successful way I found to prevent carpal hyperextension is to use a hand brace . Although it feels clumsy and the grip is awkward, it manages to prevent carpus hyperextension almost completely. I tried many different types of braces, and ended up finding a cheap brace from AliExpress that fits best (Figure 8). This brace has good palmar support and has an additional articulation on the wrist joint. After several months of using the brace, my nerve deficiencies have been completely restored. Since then, I have competed in a number of ultra-endurance long-distance competitions without any trace of the neuropraxia I used to experience.
In summary, palm neuropraxia in long-distances riders can irritate and in more severe cases impair the function of the hand. It certainly reduces the pleasure of riding. Solutions may work differently for different riders, but I am under the impression that the key element to success is to prevent hyperextension of the wrist. The use of a hand brace, in combination with aerobars, worked best for me and I hope it will help other cyclists as well.
