Each year millions of people suffer from an episode of back pain. It can arise from trauma, lifting, bending at the waist; or it can suddenly appear unprovoked. Back pain affects young and old and prevents people from doing their day to day activities.
To understand the many causes of back pain one needs to have some knowledge about the anatomy of the spine. The spine is made up of twenty four segments called vertebrae and is divided into three sections. The first seven 7 vertebrae make up the cervical spine (neck), the next twelve 12 vertebrae, which have a rib attachment on both sides make up the thoracic spine (mid-back) and the last five 5 vertebrae, make up the lumbar spine (lower back).
Each vertebra, with the exception of the first one directly underneath the skull, consists of a vertebral body in the front and a pair of smaller facet joints in the back. Connecting the vertebrae together (except the first two) at the vertebral bodies are very tough ligaments better known as discs. The vertebral bodies bear most of the weight, about 80% of the body when standing upright. The facet joints bear the other 20% and primarily function to allow controlled movement such as bending, rotating.
There are five 5 muscle layers surrounding the spine which are the multifidi, rotators, erector spinae, iliocostalis, and quadratus lumborum. These muscles work synergistically to move and support the spine. Although bending forward at the waist doesn’t look all that complicated, it is a highly complex sequence of events: the central nervous system (brain and spinal cord) coordinate the precise intensity and timing of contraction of each muscle group to make the spine move as intended.
Back pain can originate from:
Sprains and strains is an injury to muscle fibers, tendons and or ligaments. When the load exceeds the strength of soft tissue structures, they tear. When soft tissue is injured, inflammatory products are released, which leads to swelling and pain.
Arthralgia / Facet Syndrome – Facet joint surfaces are imbedded with nerve endings underneath the cartilage. If this cartilage layer wears thin from degenerative joint disease or from trauma like whiplash, the nerve endings will be irritated and this results in pain.
Disc herniation – Between each vertebra is cartilage acting as shock absorber. This is called the intervertebral disc. The disc has an outer layer called the annulus, and an inner, jelly-like material called the nucleus pulposus. If the annulus fibers weaken, the nucleus can “escape”, puncturing through the annulus. This usually occurs from a lifting incident, or may gradually occur over time without any specific trauma. If the nucleus protrudes and presses on a nerve root, this can cause radicular pain (pain radiating down the leg, usually the back and side of leg). In severe cases, sensation and muscle strength in the leg are affected.
Spinal stenosis – the space between the vertebral body and facet joints forms a canal, which contains the spinal cord. Arthritic changes to the vertebral body can cause bony projections to narrow this canal. This can cause pinching of the spinal cord, and can lead to neurological deficits in the lower extremities (numbness, tingling, weakness, muscle wasting).
Compression fractures – The vertebral body can fracture from trauma (a fall, a violent collision). Older people with osteoporosis can experience a spontaneous compression fracture. The affected vertebra loses its normal height and loses its ability to move properly in synergy with the adjacent vertebrae above and below. Recent compression fractures usually hurt with certain movements (extending the back, flexing the back, side bending) and are easy to visualize on x-ray.
Other fractures – The facet joints, transverse process, or spinous process can fracture from trauma.
Congenital anomalies – Sometimes spinal segments don’t completely separate into individual units during embryonic development. Groups of two or three may be fused together. This typically occurs in the cervical spine (neck) and sacrum (triangular bone below the spine. When this occurs, it alters normal biomechanics (movement) in that area: segments above and below the fusion are forced to move more to compensate, which can lead to degenerative changes and pain.
Ankylosing spondylitis – This is an inflammatory condition that ultimately leads to fusion of spinal vertebrae and the sacroiliac joints of the pelvis. Persons with AS will demonstrate difficulty moving the neck, and a hunched posture.
Arthritis – There are two basic types: Osteoarthritis is advanced wear and tear of a joint and is found in weight-bearing joints like the spine, hips, and knees. Rheumatoid arthritis is an auto-immune disease that typically affects the finger joints and spine. Both are inflammatory.
Pathology – Various bone pathologies including cancer can cause back pain. Renal disease can refer pain to the lower back.
Manual therapy like chiropractic combined with physiotherapy modalities can help reduce back pain that is musculoskeletal in origin. If examination and diagnostic findings suggest pathology/ organic etiology, the patient will be referred to the appropriate specialist
Some of the symptoms of lower back pain may include a dull, burning or sharp pain. The pain may be localized to one area or spread out over a broad area. The onset of the pain maybe be either gradual or sudden and may be accompanied with muscle spasm or stiffness. Pain may be felt in the leg or sensations of numbness or tingling often below the knee. It is also possible to have symptoms in the leg without the presence of leg pain. Symptoms occurring in the leg are often due to conditions in the lower spine that are causing pressure on the nerve that travels down to the leg.
Lower back pain may either be acute if a spell (or episode) of pain lasts less than 3 months. Most back pain is acute and goes away with 4 to 6 weeks of home treatment. Recurrent if acute symptoms come back. Most people have at least one episode of recurrent low back pain. Chronic if your back bothers you most of the time for longer than 3 months.
After the first time you have had low back pain, you are likely to have it again. To help keep your back healthy and avoid further pain:
- Practice good posture when you sit, stand, and walk.
- Get regular, low-impact exercise. Walk, swim, or ride a stationary bike. Stretch before you exercise.
- Wear low-heeled shoes with good support.
- Sleep on your side. A medium-firm mattress may put the least stress on your back.
- Watch your weight. Being too heavy, especially around your waist, puts extra stress on your back.
- Don’t try to lift things that are too heavy for you. When you must lift, bend your knees and keep your back straight, keep the object you are lifting close to your belly button, and avoid lifting and twisting at the same time.
If you sit or stand for long periods at work:
- Pay attention to your posture. Sit or stand up straight, with your shoulders back.
- Make sure your chair has good back support.
- Take regular breaks to walk around.