During the fitting process, we often hear about riders who experience numbness in their hands. This numbness is often correlated to compression or constriction of the nerve(s) and in the hand. Let’s talk nerdy with resident bike fit expert Coach Brady and examine the science behind this issue!
The two main nerves that are often impacted are the radial (also referred to as the median) nerve and ulnar nerve. These two nerves run through the arm and come into your hand on the palm side of your wrist. They run through the commonly termed carpal tunnel which is formed by the flexor retinaculum. These two nerves are largely responsible for the sensation and movement of the hand and wrist and often we find in fitting that excessive pressure on these nerves results in a compressed or irritated nerve thus causing hand numbness.
Wondering why this numbness is occurring for you? We often see four key areas that can result in this hand numbness and they include:
Riders often think of their saddle being too far forward is causing them to experience hand numbness, which can be true. I also see riders with a position that is too far aft, causing them to reach excessively causing hand numbness.
Many times people look at a large amount of drop and think that hand numbness is inevitable. I have also experienced the same thing with people who have raised their bars very high in the search for ultimate comfort. They ended up with more hand numbness due to an unnatural hand interaction with the handlebar.
Poor handlebar ergonomics
This is where I see one of the largest areas of rider discomfort! Whether the LBS did not notice poor handlebar setup or the bike has tipped over and shifted one of the levers, I see a great number of people whose levers are uneven, bars are rotated incorrectly, width is not correct for the rider, or lever/bar ergonomics are not correct. For the vast majority of riders, resolving this will help out immensely!
Weak core strength/weight
Now, let’s be real with ourselves. Lance’s book said, “It’s Not About The Bike,” and that may be right. With a proper position on the bike, our upper body is being stabilized by every pedal stroke, and supporting our skeletal structure is our musculature. So, if you have a weak core, (and I don’t just mean your abs) it is possible that you will suffer from hand numbness. To our larger riders, that means that your muscles have to be even stronger to support a greater amount of mass. So, work on those planks, core bridges, bicycles, superman, and other anterior and posterior chain core exercises to get the strength you need to stabilize yourself!
Remember, numbness is generally a sign of damage to the nerves. No matter the grade of that damage, it is not something that you should let continue. If you are unable to resolve the problem on your own it is time to seek expert advice and we would love to help you with any fit-related issue you may have!