The spine has many moving parts that work together to facilitate its optimal strength and function, including its intervertebral discs and surrounding muscles. A healthy spine will have its natural curves in place, its discs will be healthy, and its surrounding muscles will be strong and balanced.
Back pain can be caused by structural issues within the spine, nerve compression, disc herniation and muscle strain. A big difference between muscle strain and disc herniation is muscle pain tends to be localized around the specific muscle affected, while disc herniation is associated more with radiating pain.
Before getting to the specific roles of the spine's surrounding muscles and its intervertebral discs, let's take a minute to discuss why spinal health is so important.
A healthy spine helps us stand upright, practice healthy posture, protects important organs, the spinal cord within, works with the brain to form the body's central nervous system, and facilitates a wide range of motion.
A healthy spine is important for overall health and quality of life, and a disruption in spinal health can have a number of causes, involve a number of structures, and cause varying levels of pain and functional deficits.
The spine has three main sections, is curved in each section, consists of vertebral bodies that are stacked on top of one another, connected by facet joints, and adjacent vertebrae are separated by an intervertebral disc.
If a single spinal section is unhealthy, it can disrupt the biomechanics of the entire spine.
An unhealthy spine doesn't just affect spinal health, but also the health of the spine's surroundings, including nerves and muscles.
So let's move on to how spinal health can be affected by muscle health and vice versa.
In order for the spine to function optimally, it needs to have its healthy curves and alignment in place, and the spine's surrounding muscles provide crucial support and stability for the spine.
Back muscles that provide spinal support include the erector spinae, the multifidus, rotatores, and the core muscles also play a role (transverse abdominis and diaphragm); these muscles work together to support the spine, stabilize it, maintain healthy posture and movement patterns.
If the spine loses a healthy curve, it's not as balanced and stable, and uneven forces are introduced to the spine and its surroundings, including its muscles.
A common effect of scoliosis, for example, is muscle imbalance; this is caused by the spine's unnatural bend and twist pulling its surrounding muscles in different directions.
If muscles on one side of the spine have to work harder to counteract the unnatural curve, and muscles on the opposite side become weak from lack of use, they can become unbalanced and strained.
Strained muscles can be painful, experience swelling, weakness, and a reduced range of motion.
Muscle spasms and feelings of tightness in the area can also develop, and these symptoms are generally localized around the affected muscle(s), and this is one of the key differences between muscle strain and disc herniation.
The spine's surrounding muscles provide the spine with support and stability, and the spine's intervertebral discs are key to overall spinal health and function.
An intervertebral disc sits between each pair of adjacent vertebrae and consists of two main parts: a soft gel-like inner nucleus and a tough outer layer known as the annulus.
The discs give the spine structure as adjacent vertebrae attach to the disc in between, and the spinal discs work together to maintain spinal flexibility and a wide range of motion.
The discs also act as the spine's shock absorbers and prevent friction during movement.
Degenerative disc disease contributes to the development of a number of spinal issues/conditions, and because the discs don't have their own vascular supply, it can be difficult for them to heal after damage and/or degenerative changes.
If a disc degenerates, this can involve excessive fluid loss (desiccation) and a loss of disc height, and these types of changes can cause a degenerating disc to become a bulging and/or herniated disc.
Usually, a bulging disc develops first where the inner nucleus is pushing against the outer annulus causing the entire disc to bulge outwards, and if there is enough pressure to cause a small tear, this is when the herniation occurs as the inner nucleus pushes through.
A herniated disc can be painful, but the pain can be more widespread than a strained back muscle. A herniated disc can cause numbness and weakness, and pain/discomfort can radiate into the extremities due to nerve compression; sharp burning pain is common with nerve involvement.
The spinal cord contains 31 pairs of spinal nerves, and if a nerve is exposed to uneven pressure from a herniated disc, symptoms can develop anywhere along the affected nerve's pathway, and severity of symptoms is shaped by the degree of nerve involvement.
So if a disc herniates in the lower back, pain can radiate throughout the lower body, whereas muscle strain in the lower back is most often going to cause pain that's isolated to the lower back.
When it comes to addressing any type of back pain, the first step is determining its underlying cause. In most instances of back-muscle strain, rest, applying ice, elevating, and compression is recommended, and if pain decreases, gentle low-impact movement and stretching are recommended.
Over-the-counter pain relief medications can help reduce inflammation and pain.
Once pain is reduced and mobility returns, returning to regular activity is key to prevent muscle weakness and repeat injury.
Treatment for a herniated disc will generally start with activity modifications, over-the-counter pain medication, hot-and-cold therapy, and physical therapy; if pain persists, pain management can include prescription pain medications, anti-inflammatory medications, muscle relaxants, and/or epidural steroid injections.
In severe cases, surgical intervention may be necessary, but the sooner a herniated disc is diagnosed and treated, the more likely it is to respond to a conservative nonsurgical treatment approach.
So while a herniated disc and muscle strain can both be painful and disruptive, the pain tends to differ in where it's felt, along with the type of pain.
Muscle pain can be dull or sharp, but it's mainly localized pain surrounding the muscle affected.
Disc herniation with nerve involvement means nerve-related back pain; nerve-related back pain can be sharp and burning, described as a pins-and-needles sensation.
If a compressed, irritated, inflamed, and/or impinged nerve remains untreated, symptoms can increase and nerve damage can occur.
Muscle strain in the back can be caused by overuse, an injury, a spinal condition, or poor posture.
A herniated disc is commonly caused by degenerative disc disease, injury, strain, obesity, improperly lifting heavy objects, and genetic factors.
Muscle and disc pain can both be felt in the back, but the nature of the pain differs as pain caused by muscle strain tends to be localized and doesn't involve nerve pain and/or nerve damage, and disc pain can be felt throughout the body, depending on the pathway of affected nerves.
Here at the CLEAR Scoliosis Institute, patients complaining of back pain are given a comprehensive assessment to determine its underlying cause, and while a strained back muscle can be detected through a physical examination, postural, and mobility assessment, a physical examination and X-ray imaging is needed to diagnose a herniated disc.
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