First of all -- I know this isn't Medical-Overflow-Exchange, sorry.
But, I think my issue may be cycle related. I've been riding a lot lately, and actually just started riding Fixed again. And for about 3 weeks the whole left side of my foot and about 6-8 inches up my leg are completely numb!
I've read it could be related to my back, I've been cycling and when even not cycling carrying a sling bag for work; with a Laptop and a few notebooks in it.
Anybody come across this before?
It's not unusual for the feet to get a bit numb from long-duration riding, but the numbness wouldn't be expected to extend far from the contact point of the pedal.
The fact that the numbness extends up the leg suggests that it's neurological, likely due to a compressed nerve somewhere "upstream".
This can be a back problem, but may also be something akin to piriformis syndrome where the muscles of the upper leg compress nerves feeding down the leg. This is particularly likely if you've been hyper-exercising and are experiencing some degree of swelling of the upper leg muscles.
You need to cut back substantially in your training and see a doc. Kind of a toss-up as to whether it should be a neuro or an ortho -- I'd be slightly inclined towards the ortho, as he would be more familiar with disorders due to overtraining. Or a "sports medicine" guy might be good, if you can see one relatively quickly.
If the numbness progresses much, or if there is any accompanying paralysis, it would become a medical emergency.
I've heard that sling bags are terrible for your back. They don't distribute the weight evenly at all, and can cause major problems I don't know why they are so popular. I guess backpacks look too "high-school". But I would start by getting a backpack. They make a few of them that are specially equipped for carrying laptops.
If it's the bike, you might want to check that everything is aligned properly. Ensure that your seat is straight and level. Ensure that you handle bars are properly aligned. Check for a bent axles in the wheels and bottom brackets, although that may be less likely.
I guess a couple clarifications could help diagnose some other posibilities. Do you have brakes on your fixie? If you do have brakes, do you use them? Do you wear bike shoes or have toe clips? Is the pain always there, or only after a prolonged ride? If it's continuous, I'd definitely get myself to a doctor. That's way too long to be numb in such a large part of your body.
sounds like your aggravating your sciatic nerve. It can cause numbness on the way down to the foot. If you have lower back issues, it can do the same, but you said complete numbness. The sciatic nerve would only cause numbness and/or pain on the outside of your leg and foot. A disc problem could cause complete numbness
