Shoulder pain can stem from one or more of the following causes: 1  Strains from overexertion. 2  Tendonitis from overuse. 3  Shoulder joint instability. 4  Dislocation. Collar or upper arm bone fractures.  Frozen 1  shoulder. Pinched nerves (also called radiculopathy)
Joint pain can affect one or more joints. Joint pain can be caused by many types of injuries or conditions. It may be linked to arthritis, bursitis, and muscle pain. No matter what causes it, joint pain can be very bothersome. Some things that can cause joint pain are: Autoimmune diseases such as rheumatoid arthritis and lupus.
Septic arthritis. Septic arthritis causes inflammation of a joint because of a bacterial infection. Septic arthritis is also known as infectious arthritis or bacterial arthritis. Septic arthritis often affects the knees and hips, and may affect one joint or more than one at the same time.eptic arthritis can be caused by bacteria spreading from another area of the body. It can also be caused by a bacterial infection from an open wound, contaminated needle or an opening from a surgical procedure such as knee surgery.