Over the last couple of weeks my left pinky finger has gone numb, and there's a spot on my left wrist (palm up, right side, where the hand begins and the bone sticks out a little) where even the softest tap provokes pain through the pinky and ring finger. I can move the pinky, but it's asleep 24/7. No loss in strength. If I clench a tight fist, it gets a little feeling back. I took a week off and it's getting worse instead of better. Thoughts?
I ride my bike every evening about 12 miles, on road. No impact machinery, no trauma I know of, and yes, there is numbness on the little finger side of my ring finger, too.
Wow. That's cool. You don't see this very often. Maybe once every couple of years. This is most commonly a cycling injury, and is known as handlebar palsy. Bonus points, though, for trying to save the planet.
The ulna nerve passes through a tunnel made up of two bones in the wrist -- the pisiform and the hamate -- and, beyond this point, it supplies feeling and strength to the pinky and half of the ring finger. The tunnel is divided into three zones. Depending on where the nerve is compressed, you can get grip weakness, numbness or a combination of both.
Given your pain pattern and history, it is highly likely that purely as a result of cycling you have chronically compressed the nerve as it passes through this tunnel. This has subsequently led to inflammation that is now maintaining the problem through a more insidious pressure.
Given the wrist pain you describe, rheumatoid arthritis is a distinct, though unlikely, possibility.
First, I would try grabbing that little boney thing (your pisiform bone) on the little finger side of your wrist. Slowly, but firmly, move it from side to side for five minutes several times a day. I want you to create a little space for the nerve, and encourage that inflammation to be on its way. Initially the articulation will be quite uncomfortable, but this should subside reasonably quickly. Second, change the way you grip the handlebars, or change handlebars, bar ends, etc. Putting pressure on that part of your wrist is a no-no.
Occupational overuse injury can cause a ganglion cyst to form in the tunnel, putting pressure on the nerve. If you chronically stress your wrists at work, and the pain does not subside, it would be advisable to get an MRI.
The ulna nerve can be impinged in a few other places. None are especially likely given your wrist tenderness, but if it persists, shoot me a heads-up on the rockandice.com forum and I'll give you some more direction.
Cortisone and Tendon Injuries
Finger Cysts and Pain
De Quervains Tenosynovitis
Grip Position and Injury
Pinky Finger Pain
Finger Stiffness and Soreness
Finger Taping Truths
Torn A2 Finger Pulley
Torn A3 and A4 Finger Pulleys
Trigger Thumb Syndrome
Trigger Finger Syndrome