Low Back Pain
What is low back pain?
Low back pain is a symptom that that generally occurs because of a problem with either the lower back [muscles] musculature, the lumbar portion of the nervous system (spinal cord and lumbar nerves), or the [lower part of the] spine (called the lumbar spine). Millions of people all over the world suffer from lower back pain. Its specific etiology or cause cannot always be determined. Surprisingly, in about 80% of cases no definite source is found. [In many cases, the exact problem causing lower back pain cannot be determined.]
What is the anatomy of the lower back?
It is really important that we understand the anatomy of the lower back to understand more about low back pain. The lower back is mainly made up of nerve, bone, muscle, and connective tissue. The nervous component includes the spinal cord and its branches which come off at every bone junction in the spine. The spine is a series of square bone blocks separated by soft discs at every junction or joint. These bone blocks are known as vertebrae. The spinal cord runs down the spinal canal from the brain through a series of holes or rings on the backside of each vertebra. The structures that strengthen the spine and hold the bones together are made up of connective tissue and are referred to as ligaments. Muscle are then layered over the nerve, bone, and connective tissue and help with support and movement.
Key Points:
-- The spine is made up of bony structures called vertebrae
-- Vertebrae have holes that allow nerves extending from the spinal cord to pass through
-- Muscles and connective tissue hold the vertebrae together and strengthen the spine
What are the causes of low back pain?
There are 3 categories of causes of lower back pain:
1. Indirect Causes
2. Direct Causes.
3. Other causes.
1. Indirect Causes: Inflammation or infections of organs in the region of the lower back [area] like appendix, kidneys, urinary bladder, ovaries and pelvic region often cause lower back pain.
2. Direct pain [causes]: Problems with [the] nerves and [muscles in the lower back, including:] musculoskeletal system contribute to direct low back pain. The problems related to the nerves and the musculoskeletal system are further broken down and categorized as follows:
A. Nerve root pain syndromes.
B. Musculoskeletal pain syndromes.
A. Nerve root pain syndromes. Nerve is a very delicate structure. If the nerve is compressed, it can cause impingement and this phenomenon is known as impingement syndrome. This phenomenon can be triggered by disc herniation, also known as disc bulging. Spinal stenosis and spinal degeneration also cause impingement syndrome. Let’s look at what they are:
a. Disc herniation. With the process of degeneration of the vertebrae in which the bone structure thins out, the disc that is filled with the lubrication material just [Occurs when a disc between vertebrae] bulges out of its place and pinches on the nerve[s] roots.
b. Spinal stenosis. Spinal stenosis refers to a [Occurs when] narrowing of the bony spaces in the spine [become too narrow and pinch nerves]. This is commonly caused by trauma over many years and normal wear and tear of the elements that make up the spine. The narrowing can cause pain when the spinal cord or individual nerves are caught in these constricted spaces.
c. Spinal degeneration. [Occurs when there is The loss of the bone mass] of the spine results in the spinal degeneration. When there is disease of the joints of the spine along with the spinal degeneration, this result in stenosis of the spine.
B. Musculoskeletal pain syndrome. The musculoskeletal pain syndrome comprises of myofascial pain syndrome as well as fibromyalgia.
a. Myofascial pain syndrome [or fibromyalgia]. [Conditions that cause pain in muscles and connective tissue, often affecting the lower spine]This pain occurs at the localized areas and is typified by the loss of range of motion in a specific peripheral nerve distribution.
b. Fibromyalgia. There are about 18 points that are identified by the American College of Rheumatology as the tender points of fibromyalgia. It is on the basis of pain in these tender points that the individual is labeled as suffering from fibromyalgia. The symptoms reported in fibromyalgia are stiffness, fatigue and muscle ache.
3. Other causes of low back pain: The other causes of low back pain include osteomyelitis, in which there is infection of the spine [and spinal tumors]. Invasion of the skeletal system by a tumor can also be a cause of lower back pain.
Key Points:
-- Causes of low back pain include indirect and direct causes.
-- Indirect causes include appendicitis, bladder infections, pelvic infections, ovarian cysts or other conditions affecting other organs in the lower back area.
– Direct causes include problems with the nerves, muscles, bones, or connective tissues of the lower back.
What are the symptoms of low back pain?
Low back pain can be truly incapacitating. Below are some of the symptoms of low back pain.
[Symptoms caused by nerve or muscle problems in the lower back may include:]
1. [Pain radiating from the lower back to the buttocks and down the legs]. Radiation of pain. The pain from the lower back can radiate to the buttocks and down the thighs into the legs.
2. [Pain that worsens with activity] Activity can really worsen the pain. If an individual suffering from low back pain performs activities like lifting of heavy weights,or bending at awkward angles the pain will usually increase. Even sitting for prolonged periods can worsen the pain.
3. Another common symptom that can occur is n[N]umbness or weakness of the legs that is caused by compression spinal nerves.
Key Points:
-- Symptoms of low back pain may include:
Pain radiating to the buttocks and legs
Pain that worsens with activity
Numbness and weakness in the legs
How is [lower back pain diagnosed?] the diagnosis of low back pain made?
There are different components of diagnosing a patient who is suffering from low back pain. We can simply divide the diagnosis into three components, which include history taking, physical exam and diagnostic tests.
1. History [of symptoms] :. In this, the doctor asks the individual different questions to determine the location, severity, [and potential] causes of aggravation of pain, things that relieve pain, radiation of pain, etc. Below we are listing some of the questions that are normally asked by the doctor, which includes:
a. What caused the pain to occur?
b. Was there any injury associated with it?
c. Is there any past history of back pain?
d. Does the pain stay at the location specified or it just radiates to a different location?
e. Are there any symptoms of weakness that are associated with back pain?
f. Are there any symptoms of incontinence of bowel or bladder?
2. Physical examination [to check for:] Physical examination is an important component where the doctor confirms that the patient is suffering from low back pain, as well as performs tests to determine as to what could be the most probable cause of it. The physical examination includes:
a. Checking t [Tenderness by palpating [in] the lower lumbar spine.
b. Straight leg raising test. When the leg of the patient is raised and the patient complains of p [P]ain or numbness in the thigh or leg when it is straightened out and raised this is considered a positive straight leg raising test.This indicates that there is abnormal pressure being placed on the spinal cord or spinal nerve in the lower back.
c. Another test that is performed to determine if there is a herniated disc is crossed straight leg test. In this test, the patient raises the leg and the pain travels down the other leg. This test helps to confirm the presence of herniated disc.
d. [Weakened muscles in the lower back] The doctor performs strength testing to determine which muscle groups may have become weak. The different muscle groups are supplied by the different nerves and performing the strength test indicates which nerves are being compressed and causing the muscles to weaken.
e. [Areas of numbness or altered sensation in the legs] There are also sensory changes that occur in the area of the nerve that is being compressed. So by testing the different areas, doctors come to know which nerves are involved and where the compression of the nerves is occurring.
f. A reflex test is also used determine in the spinal nerves are working appropriately.
The most common is the “knee jerk” reflex. The patellar tendon is struck with a rubber reflex hammer and stretched. This causes a reflex firing of the quadriceps muscle and a straightening of the leg if the components of the femoral nerve are functioning properly.
3. Diagnostic Tests [may include]: The diagnostic tests performed to evaluate low back pain include:
a. X-rays, CT scans, MRI scans, or myelograms to detect abnormalities in the lower spine. Plain film x-rays are taken to see the alignment of the spine. An abnormal curvature of the spine can be easily seen on the lateral views, as well as the compression fractures. Any other deformity of the spine such as the abnormal tumor growth can be seen very easily on the plain x-rays.
b. CT scans. The CT scans give images that are three-dimensional. These views are then seen and interpreted by the doctors who can see the bone structure and the deformities very well. The only drawback is that the soft tissue structures cannot be seen with the CT scan, which can be helpful in knowing the problems of the disc, etc.
c. MRI scans. MRI scans are the same as like CT scans, but with this technique the doctors can see the soft tissue structures as well.
d. Myelogram. This technique is performed by injecting a dye into the spinal canal. After the dye is injected the x-rays are taken that show areas where the nerve is getting pinched by the bony structures because the area of compression does not allow the dye to flow further.
e. EMG/NCV. EMG stands for Electromyelogram [or] and NCV stands for nerve conduction velocity [tests to detect areas where nerves may be pinched]. These tests are performed to check the amplitude, the conduction velocities, etc. which is the electrical functioning of the nerves to determine their level of performance by comparing it with the normal values.
f. Bone densitometry. Bone density test is also another test that measures the density as well as the strength of the bones. DEXA scan is done to evaluate the bone density.
Key Points:
-- History of symptoms and examination may be all that is needed to determine the cause of lower back pain
-- Tests to diagnose lower back pain may include:
-- X-rays, CT scans, MRIs or myelograms
-- Electromyelogams (EMG) or nerve conduction tests
How is lower back pain treated?
Low back pain can be treated without surgery, but in severe cases surgery may be required to treat the condition. The treatment for low back pain consists of:
Treatment depends on the cause and severity of the symptoms and may include:
1. Ice and heat therapy. Ice and heat therapy have proven to be really helpful in cases of low back pain. It is recommended that as soon as the patient feels back pain, they should apply cold compresses. This will lessen the inflammation and may help with healing. After 24 to 48 hours most therapists will switch to heat treatments to promote relaxation of muscles and to allow for further healing.
2. Exercise [including]Exercise is a very important tool that can help prevent back pain. The exercises include stretching, swimming, and posturing exercises.These strengthen the back muscles and in turn help to decrease the back pain to a great degree.
3. Medications to relieve pain. There are several medications for low back pain. The over the counter types are usually tried initially. Stronger prescribed medication will often be necessary and will require an examination by a physician. The medications to treat low back pain include:
a. Over-the-counter nonsteroidal anti-inflammatory drugs such as aspirin, naproxen, as well as ibuprofen. There are topical analgesics as well that lessen the inflammation and improve blood flow, which include salicylates.
b. Anticonvulsants. These medicines are helpful in treating problems related to the nerves and relieve pain.
Tegretol carbamazepine
Neurontin gabapentin
Dilantin phenytoin
Lyrica pregabalin
Topamax topiramate
c. Antidepressants. There are some antidepressant drugs known as tricyclic antidepressants, which include amitriptyline and desipramine, which relieve the pain.
d. Opioid analgesics. The opioid analgesics include oxycodone, hydrocodone, morphine etc., which relieve the pain quickly. They do have an addictive nature and thus are given for short periods of time.
4. Spinal manipulation (or chiropractic treatment). This includes techniques, which are performed only by licensed personnel on an individual basis to help relieve the back pain.
5. Acupuncture. This is an alternative approach to treat back pain, which includes insertion of the needles into the points where the individual is suffering from pain. This technique is reported to provide a lot of improvement to individuals who do not respond to other forms of therapies.
6. Biofeedback. This mode is used along with other forms of therapies as an adjunct in which the individual learns to perform relaxation techniques to help improve back pain.
When back pain does not respond to initial therapy:
7. Nerve or pain blocks interventional therapy. This mode of therapy involves blocking of the nerves and it involves injecting local anesthetics, steroids, or narcotics into the joints or soft tissues.
8. Traction. This technique involves weights to apply a constant force to pull the skeletal framework to put the body in better alignment.
9. TENS. TENS is also known as (transcutaneous electrical nerve stimulation) in which the pain signals are blocked to the brain.
10. Ultrasound therapy. This mode of therapy is used to provide warmth to the body structures to cause relaxation.
11. Surgery [to correct problems causing the back pain]. There are different surgical procedures.
vertebroplasty and kyphoplasty seal fractures of the vertebrae caused by osteoporosis
Vertebroplasty - a glue-like epoxy is injected, which quickly hardens to stabilize and strengthen the bone.
Kyphoplasty – epoxy glue is injected after a special balloon is inserted and gently inflated to restore height to the bone and reduce spinal deformity.
Discectomy is the surgical removal of all or a portion of the disc that is putting pressure on a nerve. Laminectomy is the removal of the lamina, or outer bony wall of the spinal canal.
Spinal fusion is when the surgeon welds or fuses two or more vertebrae that make up the spinal column with bone grafts or metal rods to heal into a single solid bone. This eliminates motion between vertebrae segments in order to decrease pain.
Spinal fusion is used to treat:
* Injuries to spinal vertebrae.
* herniated discs.
* Abnormal curvatures (such as scoliosis or kyphosis).
* Weak or unstable spine caused by infections or tumors, or laminectomy
Key Points:
-- Back pain is usually treated with ice and heat therapy, exercise, and medications
-- Spinal manipulation, acupuncture, biofeedback are sometimes helpful
-- Nerve blocks, traction, TENS unit may help when initial therapy does not relieve pain
-- When all these modalities fail surgery may be necessary
How can lower back pain be prevented?
Measures to help prevent lower back pain:
1. Avoid excessive strain on your lower back
2. Make an effort to bend at your knees, not at your back.
3. Take care of the ergonomics of your workstation.
4. Don’t Avoid sleeping on your stomach as it will arch your back and cause pain.
5. Wear shoes that have no heels or very low [or no] heels.
6. Keep your back straight when [lifting] you want to lift something up.
Fast Facts:
Lower back pain is a symptom of problems with internal organs near the spine, the spine itself, or muscles in the lower back area
The causes of lower back pain can not always be determined; symptoms often go away on their own with rest and ice or heat
A history of symptoms and an examination can sometimes help the doctor determine the cause of lower back pain
Diagnostic tests for lower back pain include x-rays, CT or MRI scans, and test to determine if spinal nerves are pinched
Treatment for lower back pain caused by muscle strain or pinched nerves include ice and heat therapy, stretching exercises, and medications to relieve pain
If initial treatment does not relieve symptoms, additional treatment with ultrasound therapy, chiropractic therapy, or nerve blocks may be helpful
Surgery to correct problems with the spine is a last resort for lower back pain
References
http://www.ninds.nih.gov/disorders/backpain/detail_backpain.htm
http://www.wmin.ac.uk/sih/page-462
http://www.guideline.gov/summary/summary.aspx?doc_id=4112&nbr=3157
http://www.bmj.com/cgi/content/extract/332/7555/1430
Copyright 2007, MD Kiosk
