Does your pinky finger and ring finger start to tingle when you ride your bike?
This can be a sign of Ulnar nerve pressure and tension and is something that you don't want to ignore.
So how do you know if it is the Ulnar nerve and what can you do about it?
There are a few things that can indicate that the nerve is the cause of the problem.
1. One of the simplest ways is by paying attention to exactly where your tingle is felt in the hand. The ulnar nerve supplies the sensation to the pinky finger and half of the skin area of the ring finger next to it. So if it seems to be only ever in those spots - the likelihood goes up that you are irritating this nerve.
2. You can tap the inside aspect of the elbow and see if it reproduces the tingling in the same area of the hand (its always good to compare sides so you can feel any difference in response)
3. The OK sign test - make the sign for ok (thumb and pointer finger together) and then try to turn your fingers upward (like you are drinking a cup of tea and tipping the cup completely upside down) - watch for a reproduction of the pain in the ulnar region and tingling in the pinky finger as you sustain this position.
So these can tell you what may be causing the tingling or pain, so the next step is to figure out what to do about it.
This is where knowing about the typical sites of compression and things that aggravate them are important.
Now to a cyclist one of the sites of compression is around where the wrist and hand meet on the pinky side of the palm.
The ulnar nerve goes through a little tunnel like structure - but as the wrist extends and deviates - as it tends to do when you are putting weight down through your wrist for long periods - the nerve can get irritated.
If this is the main site of your compression you may need to work on keeping your wrist more neutral, using a different grip position on the handlebars or perhaps even looking at your bike setup so that you are not throwing so much weight into your wrists and hands.
Another site of compression is closer to the elbow as the nerve runs between the muscles of the forearm. Constantly gripping hard for long periods can create a compressive force on the nerve as it travels through the region.
Learning to relax your grip sporadically and even stretching and loosening the region prior to riding can pay dividends
Like all nerves the Ulnar nerve has its origins at the spinal cord - in this case at the neck. So as the nerve roots leave the neck there can be areas of increased tension or pressure at this level as well.
Common causes of pressure on the nerves around the shoulder and neck can be cervical discs, the scalene muscles (the muscles at the side of the neck) and even the region around your first rib/collar bone area - see link here. https://www.bodyandspinesolutions.com.au/single-post/2017/08/02/Neck-and-Shoulder-Pain-check-your-Scalenes
If the compression is happen in these regions it may be something that you need to have better assessed and looked at, however as a start, looking at improving not only your posture on the bike but in day to day activities is a good place to start.
The rounded forward shoulder position, the bent forward thoracic spine and the neck being in constant extension are big factors that can be addressed both on and off the bike.
Try thinking about widening your chest out and stretching the tight pec muscles at the front of your chest and shoulder. The mid back can be addressed in many ways - but you could follow the simple self thoracic (mid back) mobilisation technique using a foam roller - see link here.