Low back pain is a common condition which affects a significant portion of the population. This makes it one of the most common reasons for medical consultations and a major cause of disability worldwide. Its prevalence means that many individuals find themselves seeking relief from a variety of healthcare professionals, including physiotherapists, chiropractors, and osteopaths, each offering different approaches to treatment and management. Thankfully for the majority of people, low back pain will resolve without intervention. Many people however find themselves battling recurrent episodes and some go on to experience ongoing persistent pain. This reality emphasises the importance of understanding low back pain's underlying causes and the various pathways to recovery.
Acute Low Back Pain vs Chronic Low Back Pain
To develop a thorough understanding of this common condition, it’s important to differentiate between the types of low back pain. There are numerous potential causes and sources of low back pain, and categorising the type of back pain by its duration and/or the possible implicated tissues allows for the most suitable management. The reason for this will be explained in further detail below. The main distinctions regarding duration are:
Pain that has lasted longer than 6 months, which is usually referred to as Chronic or Persistent Low Back Pain
Pain that has only just started and lasts for less than 6 months, which is known as Acute Low Back Pain
A recent worsening of chronic pain, which is known as an Acute on Chronic Flare-up
The most commonly involved tissues/structures in low back pain are:
Intervertebral Discs: These are frequently perceived as the primary cause of back pain, though this is not always the case. These discs, acting as cushions between the vertebrae, are crucial for the spine's flexibility and shock absorption. However, they are also susceptible to damage and degeneration, leading to conditions like disc bulges or herniations that can exert pressure on nearby nerves.
Facet Joints: These play a key role in the spine's movement and can be a source of pain if they become inflamed. These are also very commonly implicated in many acute and chronic pain conditions.
Muscles: Muscles support joint movement and can contribute to pain when strained or overused.
Nerve: Nerve-related pain can occur when nerves in the lower back are compressed or irritated. This can be due to issues with intervertebral discs, facet joints or surrounding bone.
Referred Pain: Pain may stem from organs or arteries near the spine, reflecting issues not directly related to the spinal structure itself.
Understanding the Biopsychosocial Model
While the duration and tissue source are important initial considerations in managing low back pain, the biopsychosocial model takes these factors and integrates them within the psychological and social context of the person experiencing pain and disability as a result of their injury. This model is essentially a framework for understanding pain through a combined lens of biological (e.g. the degree of tissue damage), psychological (e.g. levels of stress and anxiety), and social factors (e.g. social support, work environment etc). This aligns with recent and widely accepted views on the pain experience, which recognise that pain is not always directly associated with tissue damage. Instead, it is heavily influenced by the brain and nervous system.
With consideration of this framework, pain should be thought of as a protective mechanism initiated by the brain and nervous system to protect us, which is influenced by biological, psychological and social factors as described above. When we suffer an injury, this mechanism will typically work in the following way:
immediately following an injury, the involved tissues become inflamed
The brain recognises this inflammation and increases the sensitivity of the nerves in and around the injured area to protect it further. This heightened sensitivity is known as central sensitisation and typically leads to a lower threshold for experiencing pain with any movement or strain of the involved areas.
As tissues heal and inflammation resolves, this sensitisation decreases and so to does the associated pain response to movement or strain.
In the context of chronic pain, this sensitisation can persist or worsen despite normal tissue healing and resolution of local inflammation. Imagine pain like an alarm system: it should quiet down after the threat is gone, but with chronic pain, the alarm may stay on due to factors like stress and anxiety. The biopsychosocial model can help us to understand the reasons why pain intensity, pain duration and tissue damage may not always follow a linear path.
In the case of back pain which has persisted for a long duration (e.g. longer than 6 months), this can suggest the possibility of a persisting heightened centrally sensitised state. A skilled therapist can help to determine the possible degree of persisting sensitisation vs the contribution of persisting local tissue inflammation/injury.
What Is The Most Common Cause Of Low Back Pain?
The root cause of acute, first-time low back pain remains a widely discussed topic. Currently, the prevailing view is that it results from an imbalance between the physical demands placed on the body and its capacity to absorb those stresses.
This concept of imbalance is increasingly recognised as a central theme in many musculoskeletal complaints. When strain exerted on the low back exceeds the body's resilience and strength, the tissues in the lumbar region can fail. This failure isn't about a catastrophic break but rather a breakdown in the ability of muscles, ligaments, or discs to handle stress, leading to inflammation, irritation, and pain in the affected area. It's important to acknowledge that this explanation comes into play assuming more serious or 'sinister' pathologies, such as fractures, tumors, infections, or systemic diseases, have been thoroughly investigated and ruled out.
Understanding this mechanism is crucial for both preventing and treating acute low back pain, emphasising the importance of balancing physical activity with the body's limits and the role of targeted interventions to strengthen and protect the back.
Why Does Low Back Pain Become Chronic?
For most, first-time acute low back pain will resolve without intervention. In many cases, this pain will periodically reoccur and in other cases, pain will persist or worsen. This can happen for a number of reasons, including:
Inappropriate Rehabilitation: Returning to physical activities too soon or without proper rehab can cause repeated strain on the area of injury which can lead to a recurrence of inflammation and pain.
Significant Pathology: In some cases, a more significant underlying pathology can result in persisting pain. A common example of this is a disc herniation (as shown in the figure below) which causes pressure on near-by nerves leading to muscle weakness and altered sensation in the legs and feet. In a small number of cases, more invasive intervention may be needed like a steroid injection or surgery to release pressure on the affected nerves.
Psychosocial Factors: Stress and anxiety and other psychosocial factors can amplify pain perception as discussed previously. This can ultimately lead to fear of movement through worry of creating more tissue damage. This lack of movement impairs recovery and can lead to further injury and pain, perpetuating a cycle of stress, anxiety and pain.
When considering appropriate management of chronic low back pain, the following points are critical:
Ongoing Local Tissue Inflammation or Stress: It should be determined if there is ongoing local tissue inflammation or stress that is causing persistent or recurring episodes of pain. Identifying and addressing these factors is essential for effective management.
Appropriateness of Pain Experience: It should be evaluated whether the current pain experience is appropriate for the degree of tissue 'damage'. This involves understanding and assessing all relevant psychosocial factors and deciding if the pain experience is disproportionately high relative to the actual physical injury.
These two points will guide the treatment approach, ensuring that both the physical and psychosocial aspects of pain (when relevant) are addressed. For instance, if ongoing inflammation is identified, targeted interventions such as physiotherapy, medication, or lifestyle modifications can be employed to reduce inflammation and improve the tissue's tolerance to stress. Conversely, if pain levels are disproportionate to the injury/tissue damage and psychosocial factors are present, therapies aimed at reducing likely central sensitisation, such as stress management techniques, education around pain science and gradual physical conditioning, may be more appropriate.
Identifying Your Pain Source
Identifying the source of low back pain requires a combination of physical assessment by a skilled therapist and medical imaging. Although many in the field of managing musculoskeletal pain believe imaging is often over-utilised, identifying the source of low back pain is important in circumstances where findings may influence decisions regarding management. The most common scenarios include:
Severe Pain and Lack of Improvement: If pain is severe and symptoms are not improving with conservative management (e.g., physiotherapy, activity modification, etc.);
Red Flags: If there are any ‘red flags’ that could indicate a more sinister pathology;
Worsening Neurological Symptoms: If there are worsening neurological symptoms (e.g., loss of strength and sensation).
Outside of these indications, clinical tests by a skilled physiotherapist without medical imaging can help to give an indication of the pain source and hence guide management. The most common pain sources are listed above and include the Intervertebral Discs, Facet Joints, Nerves and Muscles. For many common types of back pain however, the treatment approach might not differ substantially based on the exact pain source, making identifying the pain source unimportant.. Non-invasive treatments such as physiotherapy guided exercises and lifestyle adjustments often focus on symptom relief and functional improvement, which can be effective across a variety of conditions.
Myth Busting: Not All Disc Bulges Cause Pain
The presence of a disc bulge, often discovered through medical imaging by well-intentioned healthcare providers, is a very common concern amongst those who are experiencing or have previously experienced low back pain.
The interpretation of these medical images by a well informed health professional remains crucial for three important reasons:
Findings of a disc bulge on imaging can be incidental;
Findings of a disc bulge on imaging doesn't mean chronic or recurring pain is inevitable, and;
Incidental or relevant findings can lead to fear of movement which can perpetuate a cycle of pain and immobility.
To illustrate the first two points above, consider::
A study by Boden et al. in 1990, which found that among 67 individuals with no history of low back pain or sciatica, about one-third showed significant MRI abnormalities, such as disc bulges and herniations, without any pain
A study done by Wasserman and colleagues in 2017 investigating the lower backs of 100 athletes at the 2016 Beijing Olympics. MRI scans showed 52% had moderate to severe 'spinal disease' including moderate to severe degenerative disc changes with varying degrees of disc bulges and herniations. Weightlifting and aquatic diving had the highest incidence of low back pathology on MRI amongst competing athletes.
These are two of many studies which demonstrate that not all disc bulges are symptomatic and it is possible to perform at the highest level with disc bulges and herniations.
If your disc IS the source of your pain, will it heal?
Disc bulges or herniations can indeed be significant pain source, especially when impacting a nerve, often leading to 'sciatica' symptoms such as pain, tingling, numbness, and weakness extending to the foot. The question then arises: can a disc bulge or herniation heal? Zhong and colleagues' 2017 research gave us valuable insight into this, finding that two-thirds of disc herniations can naturally heal and be reabsorbed by the disc. Additionally, a disc bulge or herniation may still appear on scans yet become asymptomatic, indicating that with proper conservative (non-surgical) treatment, the potential for recovery extends beyond two-thirds of cases. This suggests that the body has a remarkable capacity to heal disc injuries over time, highlighting the effectiveness of conservative management for many individuals.
How Can You Relieve Low Back Pain (with or without a symptomatic disc injury)?
Regardless of the pain source, there are many things that can be done to help reduce pain and encourage healing with a symptomatic disc injury, or any other low back injury. These include:
Finding and modifying any potentially aggravating activity such as repetitive lifting with poor posture (e.g. repetitive bending and twisting).
Staying active. Appropriate, pain free movement and light physical activity will help with your recovery.
Avoiding sustained postures, especially sitting. Sitting in one position, regardless of if your posture is perfect, for a long period of time without getting up and moving will be detrimental to your recovery.
Improving the flexibility of tight and short muscles around your hips, legs and lower back.
Improving the load tolerance of the joints in your lumbar spine through specific exercises.
Improving the strength of weak muscles around your lower back/core, hips and legs, Read out blog post about core strength.
Improving your lower back control and awareness. Read our blog post about finding your neutral pelvis and spline.
How do I know if my lower back pain is serious?
Understanding whether your lower back pain demands urgent attention is crucial. Here are some key signs and symptoms, often called 'red-flags' to consider:
Presence of worsening neurological symptoms like numbness, tingling, or weakness in the legs, especially if muscle weakness is profound,
Loss of bladder or bowel control alongside an episode of back pain.,
Severe pain that frequently wakes you at night or pain that doesn't improve over time with appropriate management,
Past history of cancer along side a new, 'unexplained' back pain which doesn't respond to appropriate management.
Consulting a healthcare professional, such as an experienced sports physiotherapist for proper diagnosis and management is always advisable when in doubt. You can call to speak to directly to one of our experienced sports physiotherapists, or book online.
Should I see a Physiotherapist?
In many instances, an episode of low back pain will subside in time with appropriate rest, however if you have any of the 'red flags' mentioned above, are experiencing your first ever episode of back pain, or you have had repeated episodes and have never been assessed by an experienced physiotherapist to address the above mentioned factors, an assessment is recommended. This will help to rule out any sinister pathology, speed up your recovery and reduce the risk of recurrence.
If you would like to speak to our experienced team at ProSport physio to organise an assessment, or to ask questions and discuss your particular problem, you can call us at 0415 889 903, send us an email at hello@prosportphysio.com.au or book online. We are happy to have a no-obligation free discussion about your problem and how we can help you!
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