The concept of referred pain might be unfamiliar to you. Essentially, referred pain is the phenomenon whereby pain is experienced in a different location on/in the body to the location of an associated injury or problem. There are two types of referred pain. The first is known as somatic pain, while the second is known as radicular pain.
A very common example of somatic pain is the pain that heart attack victims experience in their left arm chest and jaw. The “source” of the relevant sensory input pathology is the heart muscle (that is being starved of oxygen as a result of the myocardial infarction i.e. blocked artery), yet the experience of symptoms is perceived down the left arm, into the jaw and across the chest. No one knows exactly why these patterns of pain emerge, but the thinking is that it is a problem of information convergence within the central nervous system i.e. somatic pain reflects the central nervous system’s limited capacity to identify exactly where in the body sensory input is arriving from.
So when there is a problem in the body, and the sensory nerves send this information up to the brain, the central nervous system responds by projecting pain and other symptoms out to the body as accurately as it can. There is actually a great deal of variation in the brain’s capacity to detect sensory input from different areas of the body. SO while the brain is not great at identifying the precise location of “the problem” during a heart attack, it is for example, very good at accurately projecting pain for problems involving for example, the skin of our hands and face. If you for example, get a paper cut, typically, you will know almost instantly where the paper cut occurs because our brains have very detailed cortical maps for our hands, and as a result of that, very good sensory-discriminatory capacity. So you feel the pain of a paper cut in a very precise, well defined location that closely matches the location of the actual injury, but you will get a much more vague set of symptoms accompanying hear attack. These variations in sensory-discriminative capacity across different body regions and parts are probably best explained as a product of natural selection and evolution.
From a Physiotherapy perspective somatic referred pain is relevant because most often we are assessing injuries, movement problems and pain problems that originate in parts of the body (joints, muscles, ligaments, tendons etc) that the brain is not excellent at pinpointing. For this reason patients can present for treatment with a complaint of “hip pain”, when the problem is for example, a lower back joint or disc problem. Or a patient complaining of shoulder pain, may actually have a problem in a joint in the neck or upper back. A patient with groin pain may actually have a problem in the ball and socket joint of their hip, while a person with a headache may have a problem in their upper neck.
Over time, doctors and physios alike have become proficient at recognizing patterns of symptoms as being indicative of a specific problems. So if you are experiencing symptoms, I would encourage you to get in touch with us to see if we can shed some light on some of likely or possible underlying problems.
Radicular pain is the term we used to describe pain that follows the distinct path of a peripheral nerve and is typically attributed to mechanical compression or chemical irritation of the involved nerve at the level of the spinal nerveroot. The classic distribution of pain down the back of one’s leg that is commonly referred to as sciatica, is in fact a form of radicular pain. When a nerve root in the lower lumbar spine is subject to mechanical pressure or exposed to inflammatory chemicals, the brain again, has only a limited capacity to pinpoint where “the problem” is coming from. Although it does appear that in cases of radicular pain, the brain does a better job of projecting pain in a more accurate distribution than in cases of somatic pain. Again, doctors and physios alike have become proficient at recognizing patterns of symptoms as being indicative of a specific problems. So if you are experiencing symptoms, I would encourage you to get in touch with us to see if we can shed some light on some of likely or possible underlying problems.
While it is useful to break the concept of referred pain into constituent types – somatic and radicular – we should mention that the emergence of either in any given patient is not mutually exclusive. That is to say that patients can, and we would argue very commonly do present with signs of both somatic and radicular pain. Pain is complex and it is our job to unravel the complexity the best we can by assessing your specific case history, medical history and current symptoms. For more information give us a call on 0296659667.