By Dr. Dineshani Hettiarachchi Sirisena
Most of us have experienced back pain at some point in our lives; this being the most common reason for missed work and the third most common reason for visits to the doctor. We spoke to Prof. Aranjan Lionel Karunanayake of the Faculty of Medicine of the University of Kelaniya, Sri Lanka to know more about the nitty-gritty of back pain.
What is low back pain?
The pain that is confined to the lumbar and sacral regions of the spine is low back pain (figure 1). It is believed that 80% of people may experience at least one episode of severe low back pain during their lifetime. Low back pain is one main cause responsible for work absenteeism. Therefore, low back pain has direct and indirect costs. Low back pain that lasts for less than six weeks, six to 12 weeks, and more than 12 weeks is called acute, intermediate, and chronic low back pain, respectively.
What is sciatica?
On certain occasions, in addition to the low back pain, the patient might experience pain radiating along both lower limbs up to the feet. This radiating pain can be the burning or pricking type or sometimes, patients may feel it as a radiating numbness. These types of symptoms occur due to the irritation of the sciatic nerve. The sciatic nerve is the longest and thickest nerve in the body, with a root value of L4-S3. Intervertebral disc lesions are one of the main reasons for sciatica (Figure 2).
Causes and risk factors
The human spine is made up of 33 vertebrae and are connected to each other by an intervertebral disc in the front and two facet joints in the back. In addition to these three joints, there are many ligaments connecting the vertebrae. Surrounding the bones, joints, and ligaments, there are a large number of muscles (Figure 3.). These muscles are responsible for causing movements of the spine such as flexion, extension, bending to the side, and rotation. Injury to any of these structures (vertebral fractures, intervertebral disc prolapse, ligament sprain, muscle strains, facet joint osteoarthritis) can give rise to low back pain.
Mechanical causes such as acute and repetitive trauma to the spine are the commonest cause of low back pain. In addition to trauma, inflammatory conditions (ankylosing spondylitis, psoriatic arthritis) infections of the spine, malignant conditions, and lesions of the genitourinary and gastrointestinal system can be responsible for low back pain. Therefore, low back pain is a condition that should not be neglected. Low back pain can affect people of any age. However, it is more prevalent among the elderly and middle-aged people. This is due to age-related degenerative changes of the spine, making it more liable for injuries.
Effects of aging on the spine
Aging is characterised by progressive changes in metabolism and physicochemical properties of cells, which leads to impaired self-regulation, regeneration, and structural and functional changes in tissues and organs. With increasing age, there are changes in vertebrae, intervertebral discs, joints, muscles, and fat deposition in the body.
- Age–related changes in muscle
Muscles lose size, strength, and flexibility with increasing age and these can contribute to fatigue, weakness, and reduced tolerance to physical stressors.
- Age–related changes in facet joints
Osteoarthritic changes of facet joints can occur and this can give rise to joint space narrowing and development of osteophytes. Osteophytes are bony spurs that grow on the spine.
- Age–related changes in vertebrae
With increasing age, there is loss of vertebral bone mass and reduction of quality of bones. This condition is known as osteoporosis of the spine and it can affect both females and males. Females are more affected than males. This reduction in bone mass and the quality of bones make vertebrae more liable for fractures.
- Age–related changes in intervertebral disc
The intervertebral disc is made up of a soft central nucleus pulposus and a firm outer annulus fibrosus. The central nucleus pulposus is made up of a more jelly-like ground substance and the annulus fibrosus is made up of firm collagenous structures. It acts as a shock absorber. With increasing age, there is dehydration of the intervertebral disc and a reduction in the amount of ground substance. Therefore, the disc can become weaker and easily bulge or break down due to stresses acting on the spine.
With increasing age there is an increase in body fat percentage, decrease in muscle mass, decrease in bone mass, decrease in the strength of ligaments and tendons, decrease in flexibility of joints, and degenerative changes of cartilages. These changes can make a person more prone to muscular-skeletal injuries and the recovery from such injuries may take a longer duration compared to a person of a younger age. Therefore, the physical activities that are undertaken must be appropriate to the physical capabilities and the age of the person.
Risk factors for low back pain
Incorrect posture while being involved in daily activities at home, during sleep, at occupation, and during leisure is believed to be the strongest risk factor to develop low back pain. In addition to incorrect posture, high and low body mass index (BMI), long-term smoking and alcohol consumption, and lack of physical exercise can also be responsible for the development of low back pain.
Low back pain during the Covid pandemic
Most of us experienced a sudden shift to remote work during the Covid-19 pandemic. Our sitting behaviour, posture, and prolonged use of computers saw an exacerbation in low back pain. The societal shifts due to the pandemic resulted in more sedentary behaviour and increased sitting time. These factors can result in both acute and chronic musculoskeletal disorders
When to see a doctor
Low back pain can be associated with nerve root irritation, severe and prolonged night pain, prolonged early morning pain, and other symptoms such as fever, dysuria, abdominal pain, chronic cough, and severe loss of weight, which could be due to inflammatory, infective, neoplastic conditions or due to the involvement of other body systems such as the genitourinary, gastrointestinal, and respiratory systems. These symptoms are also called red flags. Patients with such symptoms should see a doctor without any delay.
Even patients with low back pain that occurs due to mechanical causes, which does not respond to rest, ice, support, and simple analgesics within one week, should also see a doctor.
Investigations
These are done to find out the cause, severity, and any associated complications related to low back pain. Many types of investigations are done. They are X-rays, MRI scans, CT scans, nerve conduction studies, bone scans, and blood tests.
X-rays are the commonly used investigation due to the low cost associated and availability of this facility in many hospitals. However, X-rays can provide only a limited amount of information, such as changes in vertebrae, facet joints, and intervertebral discs. A MRI scan is still considered as the gold standard to investigate the causes, severity, and associated complications such as nerve irritations. Due to high cost and not being available in many hospitals, this investigation is ordered less frequently. CT scans provide less information compared to the MRI scan and due to the exposure to a high level of radiation, the CT scans too are ordered less frequently. Blood tests and bone scans are ordered if infective or malignant causes are suspected.
Treatment
In the acute stage of an injury, the “POLICES” (P – protection, OL – optimum loading, I – ice, C- compression, E – elevation, S – support) principle is used.
Identifying and stopping the aggravating factors will play a major role in early recovery and preventing further damage. Therefore, activities and certain movements that increase the pain should be avoided. Strict bed rest is not necessary. In the acute stage of an injury (first two to three days), modalities such as heat should not be used. What is useful in this stage is ice. Ice too should not be kept directly on the skin. Ice can be used for 10 minutes once every two hours. In addition, taping and providing support to the injured area will provide pain relief, reduce swelling, and promote healing.
Many types of treatment are used to treat people affected with low back pain. Certain types of treatment can be used alone or in combination with other types of treatment. They are medications (pain killers, anti-inflammatory medications, corticosteroids, anti epileptics, antidepressants, muscle relaxants), physical modalities (ice, infrared lamp, short wave diathermy, trans electrical neural stimulation (TENS), interferential treatment [Figures 4 and 5]), traction (manual and machine), massage, manipulations, physical exercises (Figures 6 and 7), yoga, acupuncture, support (lumbar-sacral corsets and taping), relaxation, and meditation.
Indications for surgery
Many patients affected with low back pain do not need surgical intervention. However, if there are symptoms and signs such as muscle weakness in lower limbs, sensory loss in lower limbs, impaired bladder and bowel function, and instability of spine, they may need surgical intervention. In addition, severe nerve root irritation that does not respond to medical treatment and physiotherapy, may also need surgery.
Prevention
Following the correct posture in carrying out daily activities at home, during leisure, at occupation, and during transport is essential (Figures 8 and 10). Incorrect posture during sitting and lifting an item can raise the intradiscal and intramuscular pressure significantly. Even if the correct posture is followed, avoiding lifting, pulling, or pushing items that are too heavy is important. Prolonged continuous sitting and standing postures too should be avoided. After every 30-40 minutes of sitting and standing, five minutes of standing or sitting is required. Therefore, standing workstations should have a chair closeby. Selecting the correct type of equipment and furniture for a workstation is essential.
Prior to participation in physical activities that have a greater risk of causing low back pain, it is important to see that previous injuries are adequately treated and rehabilitated. Adequately strengthening core muscles of the spine and all other muscle groups, improving general fitness and flexibility, and maintaining the ideal body weight are the other key factors that are important in the prevention of low back pain.
Take-home message
Finally, Prof. Karunanayake stated that having a proper posture at all times is important. This is applicable in all types of work. Proper treatment and rehabilitation of previous injuries causing low back pain and improving the strength and flexibility of the body while maintaining an ideal body weight are essential in the prevention of low back pain.
