Anatomy 101: "Pinched" Nerves

The human nervous system, comprised of the brain, spinal cord, and peripheral nerves, is responsible for transmitting signals between different parts of the body. Think of this as a complex system of electrical wiring in the body.  Breaking it down, our peripheral nerves play a major role in several bodily functions, including movement and sensation.    

 Just like the rest of our body, our nerves are designed to move.  A healthy and happy nerve gets a lot of movement and blood flow. Nerves consume approximately 20% of the body's oxygen supply even though they comprise only about 2% of the body's weight.  

Throughout our day our nerves are bending, stretching, and gliding while we perform normal daily activities and movements.  It is even normal for nerves to experience some temporary compression with daily activities. Many of us have had our leg "fall asleep" if sitting in an awkward position for an extended period of time.  By changing positions or moving around these symptoms go away as blood flow is restored to the nerve.   

If a nerve has been compressed or irritated for a prolonged period of time, it can become more of a problem, as unpleasant nerve compression symptoms can become more persistent.  This constant nerve compression is often referred to as a “pinched” nerve. It is also known as nerve entrapment, nerve compression, or a trapped nerve.    

Prolonged nerve compression or irritation can interfere with our nerves ability to transmit sensory and motor information through the body properly.  Symptoms of nerve compression may include: 

• tingling

• burning

• numbness

• pain

• muscle weakness

• stinging pain, such as pins and needles

Nerve compression can occur anywhere in the body but most often occurs in the neck, back, shoulder/chest, elbows, and wrists.   Nerves can be compressed or irritated by muscle, bone, cartilage, or the intervertebral disks of our neck and back. Inflammation in an area of the body can also affect a nerve’s ability to transmit signals properly.  

Commonly diagnosed conditions that involve nerve compression involve sciatica, stenosis, disk herniations, carpal tunnel syndrome, piriformis syndrome, and thoracic outlet syndrome. 

Although nerves love movement, an injury that involves a quick stretch or pull to a nerve might damage the tissue surrounding the nerve.  As this injured tissue heals, the healing process may affect the nerve’s ability to slide past surrounding tissue and structures, which can also result in nerve compression symptoms. 

In some cases, medical imaging can help diagnose the source of the nerve irritation.  However, a physical therapist can often determine which areas need to be addressed and provide helpful interventions to decrease symptoms without any imaging being done.   

Physical therapy can also help to address and improve the nerve symptoms.  Physical therapy can improve nerve mobility, increase nerve blood flow, and decrease inflammation of nerves, resulting in decreased symptoms.  Exercises can also be used to strengthen muscles that have become weak as a result of prolonged nerve compression. Hands-on techniques by a physical therapist can be used to improve the mobility of the soft tissue around the irritated nerve to help improve its function.  A physical therapist can also work to improve postural impairments that may be contributing to nerve compression symptoms.       

 In conclusion, one of the best ways to keep our nerves happy and healthy is through cardiovascular exercise.  Whether it is walking, running, or other sport activities, regular exercise helps nerves stay mobile and improves blood flow to our body and nervous system.

-Sean Tyler, DPT

Pain and the Brain

Raise your hand if you are currently dealing with pain. Now, keep your hand raised if you have been battling that pain for longer than 6 months. Is your hand still up? If so, you are dealing with a case of chronic pain. Now, chronic pain needs not to be feared or carried with us like a scarlet letter. The term chronic pain is simply a descriptor of how long someone has been in pain for, with 6 months being the general threshold for the diagnosis. You may have sustained an injury initially or your symptoms may have started more gradually, but in any event, the pain unfortunately seemed to persist longer than hoped or anticipated.

So what is known about chronic pain, or pain in general, that can help us get back to a state of being that we want? First, we know that pain is a normal and essential physiological process, necessary for our survival as human beings. Think about it this way, if you placed your hand on a burning hot stove, wouldn’t you want to know about it? In this scenario, pain alerts us to what is happening so we can remove our hand from the heat source and prevent further damage to the tissues in our hand. Without the ability to feel pain, the damage to the tissues in the hand might be more profound. Or, think about the scenario of having a broken leg. Without the ability to feel pain, we might continue walking around on an active fracture, risking a more serious injury. Pain alerts us to the damaged bone and hopefully leads us to seek medical intervention. With this being said, there needs to be a distinction between feeling occasional pain and living in constant pain. Feeling occasional pain is normal and healthy, while living in constant pain is not.

Second, we know that the longer someone has been dealing with pain, the less likely the pain is associated with their musculoskeletal system (muscles, bones, ligaments, tendons, cartilage, discs) and the more likely the pain is associated with their nervous system (brain, spinal cord, nerves). When we sustain an injury, musculoskeletal tissues become damaged and the nervous system subsequently increases the sensitivity of those damaged tissues in order to protect them while they are healing. Research suggests that most musculoskeletal tissues in the body heal within 12 weeks of injury, at which point the nervous system can return the sensitivity of the area back to a normal level. However, sometimes the nervous system is slow to return the sensitivity of the previously injured area back to normal, instead keeping it at a heightened level of sensitivity even though the tissue is now healed. This can lead to pain with many daily activities and subsequent disability. Pain is all about perceived threat, an output of our brain in place to protect us. As stated earlier, if our tissues have sustained an injury, that is a threat to our survival and our brain will likely produce a pain response in order to protect us from this threat. However, there are scenarios, as with chronic pain, where our nervous system can become extra sensitive and perceive threats at much lower levels, protecting us too much and preventing us (via pain production) from performing activities that are perfectly safe. Think of the brain and nervous system like a home alarm system. When an intruder breaks in (injury), the alarm will sound in order to alert us of the threat and hopefully protect us from further harm. However, what happens if the home alarm system becomes overly sensitive and begins to sound the alarm when a friendly neighbor rings the doorbell? Or when we walk down the staircase? Or when we receive a phone call in the home? In these scenarios, the home alarm system is perceiving threats in the absence of an intruder, making it ineffective in its assigned role. This is analogous to the brain’s role in the pain process and one suspected mechanism for chronic pain.

So what, if anything, can be done about an overactive nervous system and chronic pain? Research suggests a fair amount. For one, education needs to be at the core of the treatment strategy. We now know that teaching people about pain and the nervous system is both a critical and effective way to help reduce disability associated with chronic pain. Simply put, knowing more about pain and how it works has the potential to reduce the pain you experience on a daily basis. Establishing the distinction between pain and injury is an important step in the process of rehabilitation. Pain typically accompanies injury, but we can also experience pain in the absence of an injury or long after an injury has healed. Understanding and accepting this fact is paramount. Second, we need to keep moving. Movement is not the enemy when it comes to chronic pain. While it is true that some forms of physical activity can produce a pain response, physical activity and exercise are not to be feared. The pain we experience with exercise or physical activity are likely the result of an overactive nervous system and not necessarily indicative of injury in cases of chronic pain. With this being said, it is important to practice pacing and graded exposure when returning to exercise and a more physically active lifestyle. Pacing is another term for taking breaks when performing prolonged exercise or physical activities. Think of taking a 20 minute walk, but sitting to rest for 1 minute twice during the walk. Graded exposure refers to the process of gradually increasing your activity level of exposure to typically painful activities. Imagine a scenario where you experience pain when you walk greater than 10 minutes. Graded exposure would suggest walking for 10 minutes and stopping once you experience pain. Then, the next time you walk, you attempt to walk slightly longer than 10 minutes, perhaps 11 or 12 minutes, progressing in a systematic fashion, which provides your nervous system the space to adapt and become less sensitive to the activity of walking over time. Each time you walk slightly longer and nothing significant happens, you are telling your brain that walking is safe and no threat is present. This will bring the alarm system back down to a more normal level and, in turn, reduce the pain experienced. Third, stress management is of great importance when treating chronic pain. We know that stress and anxiety elevate the sensitivity of the nervous system. Think of the link between stress and chronic pain like pouring gasoline on a burning fire. The good news is gentle exercise is an effective way to management stress and anxiety. There are also numerous licensed psychologists and counselors out there to help treat stress and anxiety associated with chronic pain, if you feel you are in need of additional guidance.

If you or anyone you know are battling chronic pain, take the time to learn more about pain under the guidance of a physical therapist or other licensed healthcare provider. And do your best to keep moving!

Grant Hennington, DPT