If you’ve fractured or injured your collar bone, the muscle tissue may be affected. And for this reason, you may experience muscle pain under your collar bone. A break could potentially cause muscle tearing or damage, amongst other issues.
It may also have to do with the joints themselves. The collar bone forms the acromioclavicular joint and the sternoclavicular joint. If these joints become injured, the muscles around the collar bone may have to work overtime to compensate for the weakened area. They may also become tighter from the injury or also be impacted by the injury itself. Arthritis in and around these joints may also create muscle pain issues. However, arthritis isn’t as common in the shoulder or sternum area as it is in other parts of the body – such as the hands, knees, or hips.
The way you sleep may also cause issues with muscle pain under your collar bone. Again, muscles may become aggravated or shortened from certain positions.
Further, any problems with the pectoralis major muscle, subclavius muscle, trapezius muscle, or deltoid muscle may also create pain. In particular, the subclavius muscle sits directly under the collar bone. Thus, if your muscle pain is directly under your collar bone and not radiating from another source, an injury – such as a strain – to the subclavius muscle is very likely the cause. If you are experiencing another type of bone pain, check out our article here.