A herniated disc, also known as a slipped or bulging disc, is a relatively common pathology often occurring in people aged 30 to 50. The intervertebral discs play a crucial role in the spine acting as a shock absorber between the vertebrae, as well as allowing for a wide range of movement. Disc herniation refers to a condition in which the spinal discs become damaged & encroach on the nerve roots branching off the spinal cord. This can happen anywhere along the spinal column but often occurs in the cervical or lumbar region, due to the wide range of movement in these areas causing more wear & tear on the discs. For most people a slipped disc is extremely painful due to the nerve compression, however some people don’t even feel that it has happened.
Anatomy
The Spinal column is made up of 24 individual interlocking bones known as vertebrae. These vertebrae are split into 3 different sections consisting of 7 Cervical, 12 Thoracic & 5 Lumbar, followed by the Sacrum & Coccyx. Even though the vertebrae in each section look different they all have the same functional components; the body for load bearing, the vertebral foramen to protect the spinal cord & the transverse processes for ligament attachment. In between these vertebrae the intervertebral discs are found, protecting the bones by absorbing shock from body weight, trauma & daily activities such as walking, lifting or twisting.
Spinal discs are made up of 2 parts, a soft gel-like inner portion called the nucleus pulposus & a tough outer ring known as the annulus fibrosus. The nucleus pulposus, mainly consisting of water plus loose networks of collagen fibers, is where shock absorption primarily takes place. Surrounding this inner core, the annulus fibrosus is composed of tough ligamentous fibers which protect the nucleus pulposus, as well as securely connecting the vertebrae above and below the intervertebral disc.
Causes
A herniated disc occurs when excess pressure is placed on the disc causing the annulus fibrosus to become weak. This weakness can then cause bulging, cracking or ruptures within the annulus fibrosus allowing the nucleus pulposus being able to “leak” through & compress against the nearby nerve roots. The result, intense pain in the lower back followed by shooting pains into the buttock & down the leg.
The main factors that can increase the risk of a herniated disc are:
- Age – Over time the intervertebral discs naturally start to lose the fluid which normally allows them to stay pliable and spongy between the vertebrae, this is known as disc degeneration. This dehydration of the discs causes them to become stiff and unable to withstand strenuous compression, leaving the annulus fibrosus more susceptible to bulging or rupturing even from the slightest of movements.
- Lifting heavy objects repetitively or incorrectly – Lifting heavy objects can place excessive strain on the lower back which can cause a herniated disc. Especially when they are lifted without correct technique, predominantly using your back muscles instead of your legs to lift combined with a twisting motion overstress the discs increasing risk of herniation. If you have a physically demanding job, the repetitive nature of the role can also increase the risk and your placing this strain on the disc over and over.
- Obesity – Excess weight increases the stress on the lumbar spine making individuals who are overweight more likely to herniate a disc.
- Smoking – Experts suggest that putting nicotine into your system limits the blood flow to the discs causing them to break down quicker, speeding up degeneration therefore increasing the risk of herniation.
- Trauma – The least common cause of disc herniation is trauma, a serious fall or accident can lead to this pathology but is less common than the other factors.
While all these factors can increase the risk of lumbar disc herniation anyone at any time could herniate a disc.
Symptoms
Signs & Symptoms tend to vary depending on where the herniated disc is situated & the level of herniation. Typically only affecting one side of the body, symptoms can range from moderate lower back pain to extreme pain & numbness going all the way down the leg.
- Lower back pain
- Pain often down one leg from the buttock into the thigh & calf.
- Numbness, tingling or burning sensations due to nerve compression
- Pain that worsens at night
- Pain that worsens with certain movements such bending or sitting
- Muscle weakness
- Sciatic pain
- Difficulty lifting the foot (Foot Drop)
- Pain when standing from a seated position
Pain normally eases within six weeks, but during this short duration pain can be severe making daily activities difficult to participate in. However not all herniated discs can cause symptoms, as the herniation may not be compressing on a nerve & therefore not radiating any pain.
Diagnosis
If you believe this is a pathology you may be suffering with you should consult with a healthcare professional so they can conduct a thorough assessment. They will ask about your symptoms, medical history & when/how the pain started. After this a physical exam would be performed to find the source of the pain and discomfort. They will also assess your muscular strength and discover what movements trigger the pain. A herniated disc may be suspected if pain starts in the lower back and is then accompanied by radiating pain down the leg. In order to confirm this more tests can be performed, these include:
- Straight Leg Raise Test – While lying on your back & keeping your legs straight, your healthcare professional will slowly raise your affected leg until symptoms occur. If pain is felt during 30 to 70 degrees of hip flexion this indicates lumbar disc herniation. If you have a herniated disc compressing on a nerve, this particular movement recreates symptoms by increasing this compression therefore resulting in a positive test. You will also be asked if any numbness or tingling is felt down the leg while completing this movement.
- MRI (Magnetic Resonance Imaging) – This type of scan usually provides the most accurate imaging of a herniated disc, as it shows the disc, surrounding soft tissue & nerve roots. This allows your healthcare professional to actually see where the herniation has occurred & which nerves are being impinged.
- X-Ray – These aren’t often used to diagnose herniated discs as the soft tissues structures of the discs & nerves are hard to capture. However, X-Rays are used to rule out any other causes of the pain such as a fracture or bone spur, a tumor or spinal alignment issues.
Your healthcare professional can then put all this information together to diagnose the cause of your pain & discomfort. However, during the initial assessment, if no serious signs of a herniated disc are found then imaging scans may not be provided at this point. As some professionals prefer to wait & see if symptoms ease on their own within the six weeks.
Treatment
Treatment for a herniated disc can range from minimal pain management to surgical treatment. In most cases lumbar disc herniation often resolves from minimal treatment within six weeks. Your GP may prescribe painkillers or muscle relaxants to relieve short term pain and also refer you to a Physiotherapist/Sports Therapist. Your therapist will then provide you with stretches and exercises for the back and surrounding areas.
When slipping a disc, or with any injury in fact, initial response is to decrease the pain that you are in, ways to do this include:
- Rest – Bed rest is ok at first when pain is severe, however this should be limited to a couple of days as any longer than this can cause muscles to become stiff and weak. Heavy lifting & intense exercise however should be avoided for the first six weeks.
- Ice – Applying ice after initial injury can help to ease pain by reducing inflammation & muscle spasms associated with disc herniation.
- Pain Medications – Over the counter painkillers can help to treat pain & inflammation. Also your GP may prescribe muscle relaxants if spasms get particularly bad.
- Heat Therapy – Applying heat to the area after the first 48 hours, with a hot water bottle or by having a nice bath, can help to relax the muscles surrounding the injured area & reduce muscle pain & spasms.
- Hot & Cold Therapy – Some individuals find maximum relief from using a mixture of hot and cold treatment. For example, applying ice for 10 minutes, immediately followed by a heat pack or hot water bottle for 10 & repeat.
After this you can start to consider more long term solutions for the pathology, this options include:
- Strengthening Exercises
- Spinal Manipulations
- Epidural Injections
- Acupuncture
- Massage Therapy
If symptoms do not improve after these treatments & persist longer than six weeks, surgery is then sometimes considered.
Exercises
Provided are some exercises that can help lumbar disc herniation:
- Back Extension – Lie on your front with your forearms and palms flat on the floor. Slowly lift your upper body up off the floor and hold for up to 30 seconds, aim for 10 reps.
- Glute Max Stretch – Lie on your back with your knees bent, life one leg off the ground and place the outside of the ankle joint over the opposite knee. Hold the knee of the lifted leg and pull the leg in towards the body and hopefully you should be able to feel the stretch in the buttock region. Hold stretch for up to 30 seconds and try to treat 3 times on each leg.
- Pelvic Tilts – While lying on your back, place your hands on your hips & roll your pelvis back & forth along the ground. Aim for 10 sets of 3 reps
- Superman – On your hands and knees slowly lift and straighten your opposite arm and leg. Aim to complete 10 sets of 3 reps.
While completing exercises if any pain or discomfort is felt then stop immediately and rest instead.
Prevention
It isn’t always possible to prevent herniating a disc but here are some steps you can take to reduce your risk.
- Strengthening exercises – Increasing your core strength can help to stabilise and support the spine, decreasing the stress placed on your discs.
- Maintain good posture – Sitting up straight and keeping your back aligned reduces the pressure placed on the discs.
- Lose weight – If you are classed as overweight losing excess weight can help to reduce wear and tear on your discs as the load being placed on them will be less.
- Correct lifting techniques – Make sure when you are lifting heavy objects that you are doing it correctly, bend and lift from your legs not your waist.
