What is Referred Pain?
Referred pain is pain that occurs in one region of the body as a result of an injury in another region of the body. Other similar names you may have heard of that are associated with referred pain include radiating pain and the back condition - sciatica. None of the musculoskeletal structures in our body operate independently of one another. Everything is interconnected, the ligaments, tendons, and other soft tissues of our body.
The science of understanding referred pain may be difficult, especially with referred pain conditions such as sciatica, where nerve compression in the lumbar spine affects structures as far away as the foot and ankle. In the back pain condition known as sciatica, compression of the lumbar and lumbar-sacral nerve roots may cause dysfunction anywhere along the path where the nerve travels from the spine, including the buttocks, thigh, leg, and foot. This dysfunction may cause sharp or dull aches in side of the nerve root compression, or other associated types of referred pain, including weakness, immobility, and numbness/tingling. Sciatica is one example of why it is often difficult to find the pain generator causing the referred pain. The pain generator is the source of a person's place.
While the cause of sciatica is compression of one or more lumbar or sacral nerves, it is often difficult to find the precise source of the nerve root compression causing the sciatica. One thing we do know is that five spinal roots give rise to each sciatic nerve. Also, we know that once the nerves leave the spinal cord, the branch several times before the individual nerve fibers arrive at the tissues they are supplying information to. Also, we know that the nerves of the peripheral nervous system (the nerves outside the spine) unite with other nerve branches. This complexity of the paths of nerves makes the source of nerve problems challenging to diagnose. Sciatica is one example of referred pain associated with back conditions, and how complex it may be to find the precise source of referred pain.
Referred pain patterns can often be involved in joint injuries as well as soft tissue damage of the tendons and ligaments. Take one example of a person who has knee pain and heel pain. That person has had chronic knee pain spanning several years. Recently, however, that person suddenly began feeling heel pain on that same side, despite no recent trauma to that joint. Despite a careful physical examination of that heel and diagnostic X-Rays, no structural abnormalities are apparent. After ruling out an obvious injury or degenerative condition for that heel, the doctor may then consider the affect that the arthritis changes to the heel affect the rest of the leg. When one of our joints becomes inflamed or painful, our natural inclination is to change our posture and the way we walk, to take some of the pressure on that painful area. While this change in our posture and gain may provide us with some pain relief to that joint, it may end up causing us to have muscle imbalances as well as causing added pressures on the other joints involved with our walking motions. When muscle imbalances occur, making one leg stronger than the other, we may cause pain in other joints that now take on added weights and pressures that they were not designed to.
Click here to read more about soft tissue and ligament referred pain patterns.