Back Pain
At The Injury Hub, one of our core specialisms is the diagnosis and treatment of neck and lower back pain. Our founder also co-established Spine Plus—one of London’s leading spinal injury clinics—bringing years of specialist spinal experience to the broader musculoskeletal care we provide.
Understanding Back Pain
Back pain can have many causes. Most cases are mechanical in nature, involving the spinal joints, intervertebral discs, or the vertebrae themselves. However, pain can also arise from non-spinal structures such as the kidneys, uterus, bladder, or blood vessels. Increasingly, research has shown that back pain isn’t always just structural. In some cases, central sensitisation (where the nervous system becomes hypersensitive), psychosomatic influences, or emotional stress can play a role. Modern understanding now embraces a biopsychosocial model, recognising that pain is influenced by a combination of physical, psychological, and social factors.
That’s why a thorough assessment is so important—not only to identify the physical cause but also to consider the wider context of your pain. Patients often describe discomfort in the centre of the lower back or on one side. It’s also common for pain to radiate into the buttocks, which happens because spinal structures can refer pain to nearby areas. Even small movements—like lifting, sneezing, twisting, or sleeping awkwardly—can trigger an episode. In more acute cases, people may find themselves bent over and unable to straighten up. To understand why, it helps to look briefly at the local spinal structures.
Discogenic Pain
Each spinal disc has a tough outer ring (the Annulus fibrosus) and a jelly-like centre (the Nucleus pulposus) that acts not only as a shock absorber but also like a piece of scaffolding, keeping the vertebra above from compressing directly onto the one below. When this outer ring becomes overstretched or torn—often through lifting, twisting, or trauma—it can cause pain and protective muscle spasm. In some cases, the inner material bulges out and presses on nearby nerves. This can lead to symptoms such as sciatica, where pain radiates from the lower back down the leg or from the neck radiating in to the arm.
As we age, spinal discs naturally begin to dehydrate and lose height—a process similar to a sponge drying out. This age-related change, known as spondylosis, is often symptom-free in many people. However, in others, this reduction in disc volume can cause the vertebrae to sit closer together, leading to joint compression, instability, or nerve irritation.
A helpful way to visualise this is to think of your spinal discs like the suspension system of a car. When the suspension is healthy, the ride is smooth, absorbing every bump in the road. But when it wears out or loses tension, the ride can become unstable and uncomfortable.
In a similar way, degenerated or worn discs can reduce your spine’s ability to absorb shock, resulting in discomfort, stiffness and pain, this would be classed as having “discogenic pain”. If the disc has a slight bulge associated to it then compression of a local nerve can occur potentially leading to “Sciatica” and if the disc completely fails to absorb forces then increase stress occurs in the adjacent vertebral bone leading to inflammation known as MODIC Type I bone oedema.(See below)
Facet Joint Pain
The facet joints are small stabilising joints located at the back of the spine, connecting one vertebra to another. These joints help guide and promote spinal movement, particularly in bending and twisting. Over time, they can become enlarged, irritated or degenerate, especially due to repetitive strain, poor posture, or trauma. This can lead to inflammation, stiffness, and localised pain — often felt in the lower back and sometimes radiating into the buttocks or thighs.
Think of the facet joints like the hinges on a door: when well-oiled and aligned, the door moves freely; but if the hinges wear down or become rusty, the door creaks, sticks, and puts strain on the frame. Similarly, when these joints become inflamed, overloaded or enlarged they can cause pain with extension, initiation of flexion and rotation of the spine.
Facet joint-related pain is often mechanical in nature — meaning it worsens with rest and eases with movement. It may also coexist with disc degeneration, particularly in cases of spinal osteoarthritis or spondylosis, contributing to a broader pattern of back pain.
Vertebral Oedema (Modic Type I Changes)
Less commonly discussed—but increasingly recognised—is vertebral oedema, also known as Modic Type I changes. These appear on MRI scans as inflammation within the vertebral bone and are usually associated with degenerative disc disease. When a disc loses its ability to absorb load, excess stress is transferred to the adjacent vertebrae, triggering inflammation and bone marrow swelling. Over time, this persistent fluid disrupts the inner structure of the bone.
To understand this better, it helps to visualise the inside of your bone. It’s not solid—it’s made up of fine, hair-like structures called trabeculae, which form a mesh-like scaffolding. If fluid or inflammation sits within this delicate network for weeks, months, or even years, it can begin to soften and weaken the structure. The bone becomes less capable of handling normal stress, and pain may result from even minor movement or load.
A helpful analogy is to think of a crispy roasted potato fresh from the oven. If you place it in a cup and pour gravy over it and leave for an hour or two, the outer crispiness and inner potato softens, becomes a mush, losing its form. The same can happen to the vertebrae—constant fluid exposure weakens the internal support, making it more sensitive and vulnerable to pain.
Although still under active research, Modic Type I changes are increasingly recognised as a distinct and treatable cause of chronic back pain. The encouraging aspect is that these changes can repair over time, progressing to Modic Type II, which is characterised by fatty infiltration, and eventually to Modic Type III, involving sclerosis of the vertebrae.
Sciatica
Sciatica is a condition characterised by altered sensation along the path of the sciatic nerve. This can present in a variety of ways including pain, numbness, pins and needles, electric shooting sensations, or a heavy, aching feeling. These symptoms typically affect one side of the body and follow the course of the sciatic nerve, which travels from the lower back through the buttocks and down the back of the leg, sometimes as far as the foot.
There are many causes of sciatica. One of the most common is a protruded or extruded spinal disc—often referred to as a “slipped disc”—which can press on one of the five nerve roots that contribute to the sciatic nerve. Another common cause is narrowing of the spinal canal (spinal stenosis) or the exit foramina due to bony changes, such as those caused by arthritis. These structural changes can compress the nerves and lead to the familiar symptoms of sciatica.
Patients often describe symptoms that begin in the lower back and travel through the buttock, the back of the thigh and calf, and occasionally into the foot. These may range from mild discomfort to severe, sharp, burning, or shooting pain. In some cases, individuals also experience muscle weakness or difficulty with leg control.
However, not all leg symptoms are due to compression of the sciatic nerve itself. Pain can also be referred from spinal discs or joints—what’s known as somatic referral. Research has shown that these structures can mimic sciatica by referring pain into the buttock, thigh, and even as far as the ankle. In these cases of “pseudo-sciatica,”symptoms often do not travel below the knee and are typically more diffuse.
At The Injury Hub, we manage both true and pseudo-sciatica using specific orthopaedic testing, targeted manual therapy, and rehabilitation strategies. We also understand when further investigation is required. If symptoms are severe, progressive, or not responding to treatment, we can promptly arrange MRI imaging or refer for specialist or surgical input. Rather than prolonging ineffective care, our goal is to guide patients swiftly toward the most appropriate solution. Our clinical knowledge and experience in treating sciatica is extensive.
Deep gluteal syndrome refers to irritation or compression of the sciatic nerve caused by soft tissues or bony structures within the hip and pelvis, rather than from the spine. Beneath the larger buttock muscles lies a space occupied by several smaller muscles, including piriformis and quadratus femoris. This condition is relatively underdiagnosed and is characterised by pain and altered sensation in the buttock, hip, and back of the leg. These symptoms can stem from sciatic nerve irritation, but unlike classic sciatica caused by spinal pathology, deep gluteal syndrome typically results from one of two main conditions.
Piriformis syndrome
In some individuals, the sciatic nerve passes through or alongside the piriformis muscle in the buttock. When the piriformis contracts or becomes tight, it may irritate the nerve and trigger sciatica-like symptoms. However, this condition is relatively rare. At The Injury Hub, we have assessed many patients with sciatica using ultrasound and have rarely found piriformis syndrome to be the sole cause of symptoms. Unfortunately, online searches often overemphasise piriformis syndrome as a common cause of sciatica, which can be misleading. If you’ve been diagnosed with piriformis syndrome without any imaging, we strongly recommend treating that diagnosis with caution until confirmed with appropriate investigations, such as MRI.
Ischiofemoral impingement syndrome
This is another rare but potentially more likely cause of sciatic nerve irritation than piriformis syndrome. It occurs when there is narrowing at the back of the hip—often due to individual bony architecture—which compresses the quadratus femoris muscle. If this muscle becomes irritated or swollen, it can impinge on the sciatic nerve, resulting in gluteal and leg symptoms.
Other causes of sciatica
· Spinal cord cysts
· Arthritis
· Facet joint cysts
· Spondylolisthesis
· Spinal cord tumours (very rare)
· Spinal fractures
· Neurogenic claudication
Other Causes of Back Pain
Lower back pain can result from a wide variety of causes, some mechanical and others inflammatory or neurological. Below is a breakdown of less commonly discussed but important contributors to persistent or complex lower back symptoms.
Spinal Stenosis
· Central stenosis refers to narrowing of the central spinal canal, which can compress the spinal cord or cauda equina.
· Lateral (foraminal) stenosis occurs at the nerve exit points and can compress individual nerve roots.
Ligamentum Flavum Buckling or Thickening
The ligamentum flavum runs along the inside of the spinal canal. With age or degeneration, it can thicken or buckle inward, contributing to spinal canal narrowing (central stenosis) and nerve compression, particularly when standing or walking.
Micro-Instabilities
Small, abnormal movements between vertebral segments—often following injury or degeneration—can irritate joints, discs, or surrounding structures. Though subtle, these instabilities can be a source of chronic mechanical pain.
Ligament Sprains and Tears
Ligaments help stabilise the spine. Trauma, overstretching, or repetitive strain can lead to localised inflammation and pain, particularly during movement or loading.
Sacroiliac Joint Dysfunction
The sacroiliac (SI) joints connect the spine to the pelvis. Dysfunction here can mimic lower back pain, especially when standing, walking, or turning in bed.
Spondylolisthesis / Retrolisthesis
This refers to slippage of one vertebra relative to another. Forward slippage is known as spondylolisthesis, and backward slippage is called retrolisthesis. Both can disrupt normal spinal mechanics and cause nerve compression.
Seronegative Spondyloarthropathy (SpA)
A group of inflammatory rheumatological conditions that affect the spine and sacroiliac joints. This includes conditions such as ankylosing spondylitis, psoriatic arthritis, and reactive arthritis. These typically begin in younger adults and may cause morning stiffness, pain at rest, and improvement with activity. Blood tests for inflammatory markers may be normal, hence the term seronegative.
Psychological and Emotional Factors
Stress, anxiety, depression, and fear-avoidance behaviours can amplify pain signals and affect recovery. These factors often play a significant role in chronic or unexplained back pain.
Muscle Strains and Tears
Although often diagnosed, true lower back muscle tears are relatively rare. Most so-called “muscular” back pain stems from joint, disc, or ligament-related causes rather than the muscles themselves.
We are experts in everything discussed above and have strong links with some of the UK’s top spinal and orthopaedic surgeons. Whether you need treatment, structured rehabilitation, or a specialist referral, we’ve got you fully covered at The Injury Hub.