The Lumbar Spine is an intricate structure of bones (five vertebrae, numbered L1-L5) the sacrum, coccyx, muscles, ligaments, tendons, and a highly sensitive nerve and vascular supply.
- Causes of Lower Back Pain
- Symptoms and Diagnosis
- Treatment Options
Causes of Lower Back Pain
Even though incidents of lumbago and sciatica are recorded as far back as Hippocrates, for the majority of patients the true cause of lower back pain remains a mystery. Such ambiguity is a direct reflection of the complex anatomy of the spine, where there are many pain-producing soft tissues, including the articular joints, corresponding nerves, ligaments and muscles. Despite this complexity, lower back pain can be divided into several recognised categories:
- Lower Back Muscular Sprain/Strain
- Facet (Zygapophysial) Joint Pain (Dysfunction)
- Spinal Stenosis
- Slipped (Prolapse) Disk
- Sacroiliac Dysfunction
Back pain can be caused by Lifting, pushing and pulling incorrectly, sitting for long periods (e.g. driving), improper sitting (slouching), repetitive movements, overuse in sports, bending incorrectly, trauma, wear and tear of joints (osteoarthritis).
Sometimes back pain can occur without any apparent mechanism of injury.
Lower Back Sprains and Strains
Lumbar (lower back) muscle sprains and strains are the most common causes of lower back pain. When the lumbar spine is strained or sprained, the soft tissues become inflamed, causing pain and even muscle spasms in some cases.
Zygapopysial (Facet) Joint Pain
Facet or Zygapopysialjoints, are located on the back of the spine on each side of the vertebrae where it overlaps the neighboring vertebrae.
The Zygapopysial joints provide stability and give the spine the ability to bend and twist.
The term ‘stenosis’ has a Greek origin meaning ‘choking.’ Lumbar spinal stenosis is often caused by a combination of loss of disc space and osteophytes (bone spurs) causing narrowing of the spinal canal or neural foramina (the opening between the vertebrae through which spinal nerve roots travel) and causes compression on the nerves or their blood supply.
Spinal stenosis arthritis can occur in the neck, mid-back and lower back.
Prolapse (Slipped) Disk
People often describe a prolapse as a slipped disc, but this term is not medically accurate as the spinal discs are firmly attached between the vertebrae and cannot ‘slip’.
When a disk has prolapsed, a tear appears in the outer fibrous ring, which allows the soft central portion (nucleus pulposus) to bulge out toward the spinal canal, which can put pressure on the spinal nerves.
A tear in the disc ring may result in the release of inflammatory chemical mediators, which can cause severe pain.
Sciatica is a common form of lower back and leg pain, but the true meaning of the term is often misunderstood. Sciatica is a set of symptoms rather than a diagnosis.
Sciatica is the name given to any sort of pain that is caused by irritation or compression of the sciatic nerve. The sciatic nerve is the longest nerve in your body.
It runs from the back of your pelvis, through your buttocks and all the way down both legs, ending at your feet. When a structure compresses or irritates the sciatic nerve it can cause pain that radiates out from your lower back and travels down your leg to your calf.
Sacroiliac Joint Pain
The sacroiliac joint (SI joint) is located in the pelvis; it links the iliac bones to the sacrum. The sacrum is the triangular-shaped bone in the lower portion of the spine, below the lumbar spine.
While most of the bones of the spine are mobile, the sacrum is made up of five vertebrae that are fused together and do not move. The SI joint can become damaged either through injury or normal wear and tear.
This condition can make it hard to perform daily activities such as sitting, standing, walking and even sleeping. In fact, the SI joint is the primary source of pain in 5-10% of all patients with lower back pain.
Symptoms and Diagnosis
Depending on the cause and structure involved, there can be many different symptoms for lower back pain:
- Pain and stiffness in the back.
- Referred pain in the buttocks and the legs.
- Pain that worsens when bending, stretching, coughing, or sneezing.
- Tingling, weakness or numbness that radiates from the lower back and into the buttocks and legs – especially with activity.
- Activities such as walking, twisting and bending may increase the pain.
- Other symptoms include a ‘pins and needles’ sensation, or tingling and difficulty moving or controlling the leg.
- Typically, symptoms only manifest on one side of the body.
There are many different conditions that can cause back pain, so a thorough medical history is performed as part of the examination. Important questions are asked to ascertain the source of the pain, and then a physical examination will be performed.
Additional diagnostic tests for lower back pain include:
X-ray – Provides information on the bones in the spine; used to test for spinal instability, tumors and fractures.
MRI scan – Displays a detailed cross-section of the components of the spine.
Paracetamol is effective in treating most cases of back pain. A stronger painkiller, such as codeine, is also an option and is sometimes taken in addition to paracetamol.
If muscle spasms are present, a short course of a muscle relaxant, such as diazepam, can be taken. Some people find that non-sterodial anti-inflammatory drugs (NSAIDS), such as ibuprofen, are more effective.
Physical therapy such as physiotherapy, osteopathy and chiropractic treatment can help with back pain. These treatments involve exercises, posture advice, massage and techniques known as spinal mobilisation and spinal manipulation.
Injections for lower back pain
Injections can help to deliver medicines (local anaesthetic and anti-inflammatories) directly to the source of pain, so it is possible to progress with physiotherapy or other rehabilitation.
There are four injection techniques available for lower back pain:
- Caudal Epidural Injection. This targets the space that surrounds the spinal cord.
- Sacroiliac Joint Injection. These injections target the sacroiliac joint
- Facet (Zygapophysial) Joint Injection. These target the joints that link the bones of your spine.
- Nerve Root Block Injection (also known as Pararadicular Injection). This targets individual nerves in the spine.
All injections are performed using Ultrasound Imaging.
Advantages of Ultrasound Injection versus Fluoroscopy:
- No exposure to Ionizing Radiation
- Real-time needle guidance
- Direct visualization of the target of interest
- Shortens procedure time