Why Our Habitual Posture and Movement Leads to Back Pain
The way that we stand and move is determined by learned muscular patterns that we develop over the course of our lives. We first learn new ways of standing and moving very slowly, and have to consciously think about every aspect of the posture or movement that we’re trying to learn. But as we repeat the posture or movement over and over, the neural pathways controlling our muscles become stronger. We gradually become better and more efficient at the muscular pattern we’re learning, and soon, we’ve learned it so well that we don’t have to consciously think about how to do it. The result of this learning process is known as muscle memory.
We are constantly learning new ways of standing and moving. Stress, injuries, repetitive daily tasks, our personalities, and athletic training all contribute to our learned muscular patterns. These learned patterns build upon one another as we get older, making our muscles tighter, our movement stiffer, and limiting our range of motion.
It is this chronic muscular contraction, unnatural posture, and limited movement that leads to muscle and joint pain and physical degeneration. When we use our bodies in dysfunctional ways, our muscles become sore and painful and our joints and bones break down.
Muscle Soreness and Pain
As we develop learned posture and movement patterns, our nervous system starts to keep certain muscles involved in those patterns partially contracted all the time. We’re usually not aware of this gradual tightening of our muscles until the muscles become stiff, then sore, then downright painful.
In order to contract, our muscles use adenosine triphosphate (ATP) as a source of energy. Muscles that are constantly contracted, or being held in a state of tonic contraction, are working very hard even when we’re standing still. So as you can imagine, they require a great deal of energy in the form of ATP, which our body synthesizes from oxygen and glucose through the process of aerobic metabolism. But unfortunately, contracted muscles squeeze the blood vessels in the area, restricting blood flow and reducing the amount of oxygen and glucose that can be carried to the working muscles. This compression of the blood vessels is not problem during a phasic contraction, in which muscles regularly contract and release. But during a tonic contraction, constant compression of the blood vessels leads to ischemia, a condition in which lack of oxygen and nutrients can lead to pain, loss of function, cell damage, and even cell death.
Lack of oxygen flow means that cells must use anaerobic metabolism to create energy. In this process, glucose is synthesized into ATP without the help of oxygen, and lactic acid is produced as waste. As lactic acid is produced, the body breaks it down into lactate and hydrogen ions.
In a tonic muscle contraction, anaerobic metabolism is constantly happening, even during sleep. Lactic acid is continuously getting produced and being broken down into lactate and hydrogen ions. The constant muscle contraction has the same effect as a strenuous workout; the metabolic waste recycling process can’t keep up and hydrogen ions build up in the muscle. The hydrogen ions keep activating pain receptors, causing chronic muscle soreness and pain. So if muscle soreness and pain resulting from constant contraction is what you are feeling, then your pain should go away when your muscles release and oxygen flow is restored.
Muscle spasms typically occur in muscles that are already being held chronically tight. When people throw their backs into spasm, it often happens when they are doing something seemingly innocuous like reaching for a cup of coffee or bending over to brush their teeth. A small movement can put enough strain on the already tight back muscles that the stretch reflex is activated, causing the muscles to contract even more in order to prevent their fibers from tearing.
A spasm can go on for many days, and typically the pain will gradually decrease as the muscles slowly release. We must go through a process of regaining voluntary control over the muscles that are being held involuntarily in spasm. One factor that can hinder this process is our natural tendency to hold painful parts of our body stiff. We do this subconsciously in order to effectively splint an injured body part and prevent further pain that might be caused by movement. Unfortunately, in the case of muscle spasms, we often increase our own pain by keeping the spasmodic muscles tight and preventing the movement that is necessary for us to regain voluntary control.
Structural Breakdown: Strains, Disc Degeneration, and Loss of Cartilage
Our bodies can only withstand so much. When a damaging posture or movement pattern continues for a long period of time, our physical structure begins to break down. Constant compression, limited movement, and unnatural posture and movement cause soft tissues to tear, intervertebral discs to thin or rupture, and cartilage to wear away.
When muscles and tendons are stretched beyond their limit, their fibers will tear, causing what is known as a strain. A strong, unexpected force can cause a strain in any part of the body. However, just like a chain will break at its weakest link, strains typically occur in muscles and tendons that are already tight due to habitual muscular patterns.
Spinal problems are among the most common issues resulting from dysfunctional posture and movement patterns. As we build up muscle tension in our back, neck, and entire trunk, increasing pressure is put on our spine, and our intervertebral discs suffer the consequences. The more the discs are compressed, the looser and weaker their fibers become. When compression is constant, a disc will begin to bulge or protrude out from its normal boundaries. Sometimes it will press on nerve roots or the spinal cord, causing pain or other nerve sensation. Howver, if the bulge doesn’t press on nerve tissue, you may feel no pain or unusual sensation at all.
If a disc is put under a great deal of strain from constant compression or sudden increase in pressure it can rupture, allowing its contents to leak out. While this sounds like permanent damage, injured discs can be repaired if given the chance. The inflammatory process automatically kicks in to repair the disc, and if compression on the spine is reduced, a ruptured disc can potentially heal and resume its normal size and function.
Constant compression and imbalanced, unnatural posture and movement also affect the cartilage in the facet joints of the spine. Cartilage relies on the pumping action from joint movement to distribute blood and other nutrients via diffusion through joint fluid. Too much compression and too little compression both spell trouble for cartilage; it needs a moderate amount of movement, involving regular loading and unloading of weight, in order to remain healthy.
Our cartilage constantly maintains and rebuilds itself throughout our lives. However, cartilage grows and repairs itself fairly slowly due to the indirect way that it receives nutrients. If cartilage repair can’t keep up with the rate at which we do damage, cartilage cells can completely wear away. The cells which produce new cartilage, called chondrocytes, are unable to migrate outside of their designated area; so once an area of cartilage is completely worn away, it’s gone for good. Loss of cartilage in spinal facet joints causes pain as well as stiffness and limited range of motion. Reflexive tightening of the muscles surrounding the painful joints only worsens the condition by limiting range of motion and compressing the spine even more.