Muscle Flexibility, Strength, Endurance, and Chronic Back Pain

You need to ask yourself if you believe your muscles are flexible enough, strong enough, or have enough endurance to perform your desired activity. If you don’t think your muscles possess reasonable flexibility, strength, or endurance, you will need to work on this. Despite what you have heard, there is no reliable method of building muscles by simply using powders, supplements, or electrical stimulation devices to “grow” or replace muscle. This is why some form of consistent recreation is necessary in order to maintain your desired physical activity level. Your activity level is an essential part of managing chronic pain. There is no shortcut to exercise.

The difference between a pinched nerve and a pinched muscle

Did you know that a pinched muscle can actually mimic a pinched nerve? The muscles are the farthest extension of the entire nervous system. All of your body’s movements are dependent upon muscles activating in a certain manner. A pinched muscle can be overlooked when doctors tell patients they have sciatica, a loosely-used term for pain radiating from the back down the leg. In addition to a pinched nerve, a pinched muscle from any of the deep buttock and back muscles can also produce that same pain and tingling. This is frequently called referred pain.

The best example of referred pain occurs during a heart attack. First responders often ask questions about the location of an individual’s pain. Some individuals report pain that is felt in their elbow, jaw, or shoulder, not just in their chest. Our brain is more frequently called upon to respond to muscle changes or pain associated with jaw, elbow, or shoulder movements, so that part of the brain is also stimulated to respond to pain signals that originate from the heart muscle.

Localized pinching sensations in the back or buttock are thought to come from muscle fibers that activate in the direction that you need them to pull. This is why pain occurs during simple mechanical activities like bending or twisting your spine. There is no scan or way to locate these painful muscles with technology. All muscles appear the same on MRIs. An appropriate physical examination by your physician or physical therapist can determine if your muscles are too stiff, weak, and a possible cause of your pain. People describe this pain as being sharp, dull, aching, and sometimes even constant if these muscles are continually activated and painful during common activities such as sitting, weight-shifting, and moving your spine.

What happens when a skeletal muscle is starved of oxygen or nutrients?

Frequently the muscles make lactic acid, which further starves them of vital oxygen and nutrients. Muscles then develop localized trigger points that can be felt just under the skin and fatty tissues. Some people are even sensitive enough that they feel these areas swell or enlarge temporarily. It is easy to become alarmed when these feelings happen.

However, you really should just think of these trigger points as occurring because the muscle doesn’t have sufficient flexibility, strength, or endurance to perform required work. Any change or problem with a particular muscle’s flexibility, strength, or endurance can cause pain receptors to start firing and signal to the spinal cord that something is wrong. The best way to minimize these signals is to improve your overall flexibility, strength, and endurance. Muscles repair and rebuild themselves through a consistent and rigorous exercise program.

First, muscles must have enough flexibility or “stretchiness.” One way to think of muscles and tendons is to compare them with rubber bands. When we are young, muscles and tendons have natural elastic properties. That’s why children and teenagers do not usually have chronic pain. As we get older, we lose these elastic properties and some flexibility. The stretching exercises taught in physical education classes are intended to encourage a lifelong habit of stretching and maintaining flexibility.

This is why people who have had poor flexibility all their lives or who do not exercise are at a higher risk of developing back pain. Neglecting a consistent stretching program can contribute to the natural stiffness and muscular aging process. When a short, tight muscle is stretched, pain receptors within the muscle naturally respond to alert the spinal cord. Some experts believe these sensors are calibrated incorrectly or are responding to faulty information, therefore causing chronic pain.

How can you tell if your flexibility is affecting your back pain?

There is an easy test to see if your lack of flexibility is contributing to your back or buttock pain. Simply sit in a chair and cross one leg over the other and bend your trunk forward. If this produces some of your pain, there is a high likelihood that improving your muscle flexibility may decrease your pain.

Do this with your other leg and see if there is a difference. If there is a noticeable difference from side to side, it may mean the muscles on your painful side are substantially shorter than the muscles on your non-painful side. If you hurt on both sides, or even your “good” side, this indicates improving your flexibility may reduce your pain.

Next, muscles must have the strength to be able to generate enough force to control our joints. Our gluteal (buttock) muscles must generate force to control our pelvis while standing on one leg. This concept is something we all learned when we were learning to walk. We figured out that if we can stabilize our hip, we can put all of our weight on that one leg. If we stabilized the other hip, we could take another step. By repeating this process, we learned how to walk.

Weight gain’s effect on your muscles and back pain

Another important thing to remember is that our muscles are accustomed to moving only our current weight. If you gain an extra 50 pounds, those buttock muscles have a much harder job controlling your hip and are more prone to being strained or injured by sudden or unexpected activity. Even slight gains in weight may lead muscles that were previously able to compensate without back pain to become painful.

Knee pain, foot pain, and even neck pain are not uncommon as people gain weight. Going up stairs requires your muscles to propel your entire body weight vertically and increases the demand on other joints and muscles. Many patients also have knee pain along with their back pain. They may develop plantar fasciitis as they gain weight and become progressively less active. This results in increasing pressure needed for the plantar fascia to continue working. Keep an eye on your weight and do what you can to maintain a healthy weight and a regular exercise program.

It is also helpful to consider horsepower to weight ratio. Weight itself is not necessarily a factor if you have enough power to move it. Some professional athletes or football players can weigh more than 300 pounds, however, their muscle power is more than enough to allow them to work at that high level.

People who have heavy work demands need to make sure their muscles are operating at 100 percent efficiency. We do not know at this time what the ideal horsepower to weight ratio in human being needs to be to combat back pain. However, a person who weighs 250 pounds needs stronger muscles to function than a person who weighs 150 pounds. Increasing muscle power is especially important for easing back pain, and especially important if your muscles must carry additional body weight. Studies have confirmed that overweight or obese adults who exercise feel pain during day-to-day activities.

Endurance and your muscles

Muscles must have sufficient endurance, or the ability to contract repeatedly over a period of time. Standing for 15 seconds activates the same muscles as standing for two hours. So, if you can stand for 15 seconds, you have sufficient strength. If there is no way you can stand comfortably for two hours, then the only difference is explained by endurance.

Usually if a person does not have enough flexibility or strength to start an activity, then having the endurance to continue the activity is even less likely. A regular cardiovascular or aerobic exercise program is essential. As we age, our endurance can diminish. This may explain why many Olympic athletes are rarely able to perform at the same level at age 40 as they did when they were 20. What was an easy workout when we were 20 years old becomes much more difficult at 40, especially if we have not maintained the same exercise program over the intervening 20 years.

Exercise to relieve your back pain

As people become overwhelmed with taking care of kids, work, and busy schedules, frequently they have less time to exercise. It doesn’t matter whether you walk, run, swim, or bike—what matters is a consistent record of activity. Your muscles only understand recent activity. This is like a “bank” of energy that your muscles need to use whenever you move your body. A heavier body requires you to make more withdrawals. You can’t keep borrowing from this bank without contributing to it on a regular basis.

Many people with chronic back pain tell us they are already exercising. In that case, what your back pain is telling you is your exercise program is still not sufficient to control your body’s muscles and current weight requirements. We recommend you increase your exercise regimen even more for another 6 to 12 weeks and see if you still have pain. If you do, then you’ll likely need to do even more exercise. Talking with a physical therapist or physician at that time may be a reasonable plan.

We’ve discussed several possible reasons why inflexible, weak, or easily fatigued muscles could be causing some of your chronic back pain. Do you have pain over those particular muscle groups? The typical muscle groups that cause pain include:

  • Gluteal muscles
  • Lumbar muscles
  • Paraspinal muscles
  • Quadratus lumborum muscle
  • Spinal multifidus muscle

Have you had an MRI or X-ray? If so, do not worry.

It may be hard to believe that your pain is coming from your muscles because it feels so deep. Many muscles are quite deep and because they attach to bones, their pain can feel like it is coming from deep within the bone. Of course, you may be able to feel a tender muscle if it is very close to the skin. We do have muscles in the back that most of the time you may be able to feel. Some people feel that this area even “swells” or spasms with increases in pain.

If an appropriate X-ray or MRI has been done and there are no worrisome findings in the bone like a fracture or tumor, you may rest assured that although this pain feels like it’s in the bone it really is nothing to be worried about. If activities such as bending or twisting make the pain more intense and you have had an MRI that only shows disc bulges, you should start thinking of the pain as coming from these deep muscles and not as the disc bulge damaging the nerve root.

Last reviewed: 
April 2018

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