Most people do not know about the subclavius muscle, but it can be the source of pain in the area of your biceps brachii, your inner forearm or your first three fingers.
If you have a rounded back posture or if you are working a lot on your desk – writing and reading – the chances are good that this muscle is tight or even contains tender or trigger points.
With trigger points in this muscle, you might feel pain all the way down your arm.
It may even radiate into your thumb and first two fingers. The darker the red in the picture below, the more common it is to feel pain in the respective area when trigger points are present in this muscle.
Hence, this muscle can, among others, contribute to the following pain symptoms.
Click on the just placed links to learn how you can relieve the corresponding pain.
I know of no activities that may be impaired with this muscle being too tight.
Still, it might leave you with a tight feeling in your chest and may impair your shoulder flexibility.