You Can't Actually "Slip A Disc"
You’ve been told you’ve slipped a disc. Herniated a disc. Have a disc bulge. Hurt your disc, so it’ll never be the same again. As a Physical Therapist, I hear this all-too-common story from my patients. I’d like to share some anatomy facts to calm the widespread fear of the “slipping discs”.
What Is A Disc?
You’ve heard of discs, but do you know what they really are? Don’t feel alone. Most people don’t. Here are the basics. We have 33 vertebrae that make up our spine. They provide us with a framework for movement and protection for our spinal cord. There are 7 cervical vertebrae (your neck), 12 thoracic (the middle of your back), 5 lumbar (low back), 5 sacral, and 4 coccygeal (by your tailbone). Between each vertebrae, except C1-C2, are intervertebral discs that act as shock absorbers, aid in movement, and assist in holding the vertebrae together. When we are under the age of 30, these discs are soft, flexible, and absorb shock well. As we age, the intervertebral discs lose flexibility as part of the normal again process.
Discs are made up of 3 main components: annulus fibrosus, nucleus pulposus, and cartilaginous end plates. The outer ring, called the annulus fibrosus surrounds an inner gel-like substance called the nucleus pulposus. The nucleus pulposus contains the most fluid and resists compression to help evenly disperse forces across the disc and prevent excessive forces on the end plates. increasing the strength of the discs. The joints between the vertebrae and discs are called symphysis joints and are extremely STRONG!! The end plates hold the disc in place and with both a bony and cartilaginous component, so a disc simply CANNOT “slip out of place”.
To give you an idea of how strong thoracic discs are, for example:
A study showed that to compress the disc height 1mm, 740 lbs of force was required for discs 28 years old (+/- 8 years), and 460 lbs of force was required for discs 70 years old (+/- 7 years). These were cadaveric discs, meaning they had no bony support or active muscle contraction surrounding the disc, which further increases the strength of the discs. Let me repeat. Discs DO NOT just SLIP out of place.
Can I injure a disc?
Yes, discs CAN be injured. They can bulge or they can herniate. A disc bulge means that the annulus fibrosus (outer portion) has weakened and the nucleus pulposus (inner portion) is extending out of it’s normal area, as seen in the diagram. A bulged disc is more common than herniation. A herniated disc happens when a portion of the nucleus pulposus extends outside the borders of the annulus fibrosus. This can irritate the surrounding nerves, resulting in pain. However, many people who have a disc bulge or herniation experience no symptoms.
Do I need an MRI?
There is staggering research that indicates many people beginning at the age of 20 have some degree of abnormality on an MRI, which are just normal parts of the aging process. MRIs can be misleading. A “pathology” may be found on your MRI, that is part of the aging process and is not the cause of the pain you might be having. In a 2014 study, over 25% of healthy and pain free people in their 20s had disc degeneration or bulges in their lumbar spine MRI or CT images. This progressively increased with age to over 75% of people in their 80s with the same findings. I always recommend that my patients base their care on their symptoms. Images can be expensive and worrisome for patients that may not have them properly explained to them. Images can be very helpful and critical for identifying certain conditions, but I do recommend that patients consider their symptoms and that some “pathology” may be a normal aging process.
Symptoms of Disc Bulges and Herniations
Many people with disc injuries experience NO PAIN. You may have disc bulges or herniations anywhere in the cervical, thoracic, or lumbar spine, with lumbar being the most common. However, if you do experience symptoms from these injuries, here are some of the most common symptoms:
Pain in the neck, back, low back, arms, or legs
Inability to bend or rotate the neck or back
Numbness or tingling in the neck, shoulders, arms, hands, hips, legs, or feet
Weakness in the arms or legs
Limping when walking
Increased pain when coughing, sneezing, reaching, or sitting
Inability to stand up straight; being "stuck" in a position, such as stooped forward or leaning to the side
Difficulty getting up from a chair
Inability to remain in 1 position for a long period of time, such as sitting or standing, due to pain
Pain that is worse in the morning
Do Discs Heal?
If you have injured a disc, the great news is… YES! DISCS CAN HEAL! Studies have shown that depending on the severity, spontaneous healing occurs in 43-96% of cases with conservative treatment (such as physical therapy instead of surgery). I recommend that my patients undergo 6 weeks of conservative treatment for pain that may be due to a disc injury prior to getting any imaging or looking into invasive treatments (ie. Surgery). Getting evaluated by a physical therapist can help identify movement patterns and muscle imbalances that may be contributing to your pain and are easily improved with education, neuromuscular re-education, and manual therapy. This can be a much more cost effective option for patients and have great long-term results.
So, the next time you hear someone say they’ve “slipped a disc”, you can help them understand that discs do not slip and guide them to see a physical therapist as soon as possible to get back to pain free movement!
About the Author
Dr. Rhianna Wickett, Physical Therapist, graduated from the University of South Dakota (USD) with a Doctorate of Physical Therapy. She is also a Certified Strength and Conditioning Specialist through the National Strength and Conditioning Association and an EMT. While at USD, Dr. Wickett researched the effects of various treatments including manual therapy and exercise on trigger points, which is a common cause of pain within the shoulder girdle. She has also completed The Otago Exercise Program: Falls Prevention Training, an evidence-based fall prevention certification. Her clinical studies emphasized Women's Health, Neurological and Vestibular Conditions, and Orthopedics. She graduated with a Bachelor of Science in pre-medicine from the South Dakota School of Mines & Technology after completing two years of Industrial Engineering education. Rhianna grew up with a love of ballet, dancing for almost 20 years. She is passionate about providing each patient individualized care backed by the latest research and educating patients about their condition to make lifelong changes. She also has completed continuing education in women's health physical therapy to treat a wide range of conditions relating to pelvic floor health throughout the lifespan, including pre/post-natal conditions, incontinence, prolapse, sexual dysfunction, pelvic pain. In her free time, Rhianna enjoys spending time outdoors with her husband, family, friends, and dog Zippy. You may contact the author with questions at Rhianna@ElevatePerformanceSD.com.