Why Your Shoulder Pain Might Not Be Coming From Your Shoulder
Your shoulders help you perform many activities such as hanging curtains, lifting weights, or swinging a tennis racket. According to the American Academy of Orthopaedic Surgeons, the shoulder joint is a relatively mobile one because, like your hip, it's a ball-and-socket joint. Yet compared to your hips, your shoulder is less stable, which is why millions of people every year see the doctor for shoulder injuries. While most shoulder injuries stem from the tendons in the rotator cuff, other causes for shoulder pain can be arthritis, bone spurs, dislocated shoulders, and bursitis in the shoulder joint (per Penn Medicine).
Sometimes the pain in the shoulder might not originate in the shoulder but somewhere else in the body, according to Physio. That's because so many nerves and tissues connect the shoulder with other parts of your ribs, abdomen, and upper back. Neuragenex says your shoulder pain could be due to a strain in your intercostal muscles, which are the bands of muscles that connect your ribs. This is known as "referred pain."
How the intercostals can become injured
If you place your fingers between your ribs, you can feel your intercostal muscles expand on your inhale and contract on the exhale, according to Osmosis. You could strain your intercostal muscles by lifting heavy objects or making any movements that require twisting, reaching overhead, or forceful efforts. That's why swimmers and tennis players can be susceptible to an intercostal strain. A car accident or other trauma could injure your intercostal muscles. However, you can strain your intercostal muscles if you have poor posture while sitting or standing.
A strain in your intercostal muscles could be painful if you sneeze or cough (per Neuragenex). It could also make it difficult to reach overhead or take deep breaths. While your shoulder might be in pain, touching your intercostal muscles might also feel painful. Tight or strained intercostal muscles will also interfere with your mobility. Referred pain from your intercostal muscles could also be experienced in your arm.
Referred shoulder pain could stem from other conditions
You could also experience referred shoulder pain as a result of more serious conditions, according to Kaiser Permanente. One potential source of shoulder pain is abdominal issues, including conditions like gallstones or pancreatitis. A ruptured ovarian cyst or other pelvic complications can radiate pain to the shoulder region. If your shoulder pain is in your left arm and shoulder, this could signal heart conditions like a heart attack or pericarditis.
Pain in the entire shoulder area, including your shoulder blades, upper chest, and neck might be caused by problems in your lungs like pneumonia. Referred shoulder pain can also be attributed to other conditions like herpes zoster (shingles), Paget's disease, or thoracic outlet syndrome. Lastly, issues following laparoscopic abdominal operations or certain gynecological surgeries may contribute to shoulder discomfort. You could have referred pain from any of these other conditions or locations in your body if your shoulder pain doesn't change when you move your shoulder.