Sciatica Pain: Causes, Symptoms and Evidence‑Based Treatment
Sciatica Explained – What’s Really Causing Your Leg Pain
Sciatica is a pattern of symptoms, not a diagnosis in its own right. It describes pain, altered sensation, or weakness that travels from the lower back or buttock down the leg, following the pathway of the sciatic nerve. This distinction matters, because the same symptom pattern can arise from several different underlying causes — and effective treatment depends on identifying which of those is relevant to you.
Sciatica is extremely common and affects a significant proportion of adults at some point in their lives. Most people will experience it as a temporary episode rather than a permanent condition, and in the majority of cases it improves without invasive treatment. Understanding why sciatica occurs, what influences recovery, and when intervention is actually needed can make a substantial difference to both outcomes and confidence.
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The Sciatic Nerve – A Brief, Useful Anatomy Overview
The sciatic nerve is the largest nerve in the body. It is formed from nerve roots exiting the spine at L4, L5, S1, S2 and S3, which combine in the pelvis before passing through the buttock and down the back of the thigh.
Irritation or compression can occur:
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At the spinal nerve root level
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Within the pelvis or deep gluteal region
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Further along the nerve’s course in the thigh or lower leg
This is why sciatica does not behave the same way in every person — and why overly simplistic explanations often fall short. If you’d like a clearer understanding of the underlying structures involved, you may find it helpful to read the dedicated spinal anatomy page before continuing.
How Sciatica Can Feel – And Why It Varies So Much
Sciatica does not feel the same for everyone. While it’s often described as “pain down the leg”, the reality is far more variable — and many people worry their symptoms “don’t quite fit” what they’ve read online. In practice, this variation is entirely normal.
Sciatica-type symptoms may include one or more of the following:
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Sharp, shooting, or electric-type pain travelling from the buttock into the thigh, calf, or foot
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A deep ache in the buttock or back of the leg that comes and goes
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Burning or hot sensations, particularly when sitting
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Pins and needles, tingling, or numbness in part of the leg or foot
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A feeling of weakness, heaviness, or reduced confidence in the leg
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Symptoms that can worsen with sitting, bending, coughing, or prolonged postures
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Leg pain/symptoms with little or no back pain.
Some people experience constant symptoms, while others notice them only with certain movements or positions.
Symptoms may also shift location over time — improving in one area while appearing elsewhere.
This range of presentations is one reason why sciatica should be understood as a symptom pattern, not a single condition.
Common Causes of Sciatica
Although sciatica is often spoken about as a single condition, there are several distinct mechanisms that can produce sciatica-type symptoms. Identifying which of these is most relevant is essential, because each behaves differently and responds to different management strategies.
Broadly, causes can be divided into spinal (lumbar) causes and non-spinal or peripheral causes.
Spinal (Lumbar) Causes of Sciatica
Spinal causes originate from the lower back, where nerve roots exit the spine before forming the sciatic nerve. These are the causes most people are familiar with — but they are not the only ones.
Disc Herniation or Disc Bulge
A disc herniation occurs when disc material moves beyond its usual boundary and irritates or compresses a nearby nerve root. This can produce sharp, shooting leg pain, often accompanied by pins and needles, numbness, or weakness.
Importantly, the size of a disc bulge does not reliably predict symptom severity. Small disc changes can be very painful, while larger findings may cause few symptoms at all. This is one reason why imaging alone rarely tells the full story (Disc-related back pain page).
Degenerative Changes
With time, normal age-related changes can reduce the space available for nerve roots. These may include disc height loss, joint thickening, or bony changes around the spinal canal, which can lead to spinal stenosis.
Degenerative changes are extremely common — even in people without pain — and only become relevant when they alter nerve function or sensitivity. Symptoms may develop gradually and can fluctuate with posture, activity, or load.
Degenerative Disc Disease is one of those medical terms that can sound far more worrying than it often is. Much of the fear surrounding it comes from misunderstanding—either by patients themselves or from how the diagnosis has been described to them. I’d strongly recommend reading the dedicated Degenerative Disc Disease page to gain a clearer, more balanced understanding.
Spinal Stenosis
Spinal stenosis refers to a narrowing of the spaces within the spine, often affecting older adults. Symptoms may include leg pain, heaviness, or weakness that worsens with standing or walking and improves with sitting or bending forward.
This presentation often differs from disc-related sciatica and benefits from a tailored management approach rather than generic “sciatica exercises”.
Spondylolisthesis
Spondylolisthesis occurs when one vertebra shifts forward relative to another. This can alter load distribution and reduce space for nerve roots, sometimes leading to sciatica-type symptoms.
Symptoms may be position-dependent and can be influenced by posture, activity level, and spinal stability rather than nerve compression alone.
How spinal causes often present
Spinal causes of sciatica are commonly associated with:
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Back pain alongside leg symptoms
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Sensitivity to bending, lifting, coughing, or sneezing
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Clear neurological findings on examination (strength, reflex, or sensation changes)
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Symptoms influenced by spinal position or load
Non-Spinal / Peripheral Causes of Sciatica
Not all sciatica originates from the spine. In some cases, the sciatic nerve or its branches are irritated after they have already left the spinal column.
These presentations are frequently misunderstood and can be missed if assessment focuses only on the lower back.
Deep Gluteal or Piriformis-Related Nerve Irritation
In the deep buttock region, the sciatic nerve passes close to several muscles and connective tissues. Irritation here can produce leg pain that closely mimics spinal sciatica but behaves differently.
Symptoms are often influenced by:
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Sitting tolerance
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Hip position
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Prolonged postures
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Activities involving sustained loading through the pelvis
Back movement may have relatively little effect on symptoms in these cases.
Pelvic or Hip-Related Contributors
Reduced hip mobility, altered pelvic mechanics, or local joint irritation can change how load is transferred through the lower limb, indirectly increasing strain on neural structures.
In these cases, addressing hip or pelvic function can significantly reduce leg symptoms — even when the spine itself is relatively uninvolved.
Local Trauma or Prolonged Compression
Direct trauma, prolonged sitting, or sustained pressure on the nerve can sensitise neural tissue. This is sometimes seen after periods of immobility, certain occupational postures, or long drives.
Symptoms may appear without obvious back pain and can feel unpredictable or positional.
How non-spinal causes often present
Peripheral causes of sciatica tend to involve:
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Minimal or inconsistent back pain
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Symptoms strongly influenced by sitting or hip position
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Pain reproduced by local palpation or specific movements
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Less obvious neurological deficit on standard testing
Why This Distinction Matters
Different causes of sciatica may produce similar symptoms, but they do not all respond to the same treatment. This is why a careful assessment — rather than a generic diagnosis — is essential for effective management.
How Sciatica Is Assessed
Because sciatica describes a pattern of symptoms rather than a single diagnosis, a careful and methodical assessment is essential. The aim is not simply to confirm that symptoms are “sciatica-like”, but to understand why they are occurring, what structures are involved, and which factors are most likely to influence recovery.
A meaningful assessment looks beyond the label and focuses on how your symptoms behave.
Detailed Symptom History
Assessment begins with a thorough discussion of your symptoms. This is often the most informative part of the process.
Key areas explored include:
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Where symptoms start and how far they travel
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The quality of symptoms (sharp, burning, aching, numb, weak)
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What makes symptoms better or worse
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How symptoms behave over the course of a day
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How they respond to activity, rest, sitting, or movement
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Any previous episodes, injuries, or contributing health factors
Patterns within this history often provide strong clues about whether symptoms are more likely to be spinal, peripheral, load-related, or influenced by movement habits.
Observation of Movement and Posture
How you move can be just as important as what you feel.
This part of the assessment looks at:
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Natural posture and movement strategies
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How you bend, walk, sit, and change position
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Whether symptoms are influenced by specific spinal or hip movements
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Signs of protective or guarded movement
Rather than searching for a “perfect posture”, the goal is to understand how your body manages load and whether certain movement patterns are contributing to symptom persistence.
Neurological Examination
Neurological testing helps determine how well the nervous system is functioning.
This may include assessment of:
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Muscle strength in the leg and foot
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Sensation to light touch in different areas
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Reflexes, where appropriate
Changes in these findings can help localise nerve involvement and establish a baseline for monitoring progress. Importantly, minor changes do not automatically indicate serious damage and are interpreted alongside the full clinical picture.
Functional Testing
Assessment is not limited to static tests. Where appropriate, functional tasks relevant to your daily life are explored.
This may include:
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Sitting tolerance
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Walking or standing capacity
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Task-specific movements related to work or sport
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Repeated or sustained activities that influence symptoms
Understanding how symptoms behave during real-world activities is often more useful than isolated tests alone.
When Imaging Is (and Isn’t) Helpful
Imaging such as MRI is not routinely required in the assessment of sciatica.
Scans are typically only considered when:
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Symptoms are severe or progressively worsening
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There are red-flag features suggesting serious pathology
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Results are likely to change management decisions
It’s important to understand that imaging frequently shows disc bulges, degeneration, or “abnormalities” in people with no pain at all. Findings need to be interpreted carefully and always in the context of symptoms and examination.
Pain Severity, Nerve Sensitivity, and What Symptoms Really Mean
Sciatic pain can be intense, sharp, and deeply distressing. When pain is severe or persistent, it is entirely understandable to worry that a nerve has been “damaged” or that something serious is being missed. In reality, the intensity of pain does not reliably reflect the degree of tissue injury.
Nerves are highly sensitive structures designed to respond quickly to change. They can become irritated or sensitised without being permanently harmed. When this happens, normal signals are amplified, and pain can feel disproportionate to any ongoing physical injury. This sensitivity can be influenced by a range of factors, including movement, posture, sustained load, inflammation, fatigue, stress, and overall health.
Because of this, sciatica symptoms often fluctuate. Pain may change location, vary in intensity from day to day, or respond differently to the same activity at different times. These fluctuations do not necessarily mean that damage is worsening — they are a common feature of nerve-related pain.
This sensitivity also explains why many people improve over time with appropriate management, even when early symptoms feel severe or alarming. As contributing factors are addressed and confidence in movement improves, the nervous system often settles and symptoms reduce.
Understanding the difference between nerve sensitivity and nerve damage is important. It helps reduce fear, discourages unnecessary restriction of movement, and supports a more measured, proportionate approach to care — one that focuses on recovery rather than avoidance.
When Sciatica Needs Urgent Medical Assessment (Red Flags)
Most episodes of sciatica are painful and disruptive, but not dangerous. However, a small number of situations require urgent medical assessment because they may indicate significant nerve compression or a more serious underlying problem. In these cases, the priority shifts away from day-to-day symptom management and toward urgent investigation.
If you experience any of the following, seek urgent medical advice the same day — and if symptoms are severe or progressing quickly, attend A&E.
1) Rapidly Worsening Weakness
It is common for sciatica to make a leg feel sore, tired, or “not quite right”. What is not typical is rapidly worsening, objective weakness, for example:
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Foot “slapping” the floor or catching when walking (possible foot drop)
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The knee repeatedly giving way
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A clear, sudden loss of strength compared with the other side
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Weakness that is progressing over hours or days
Progressive weakness can indicate increasing nerve compromise and should not be ignored.
2) Bladder or Bowel Changes
Sciatica can be painful enough to distract you from normal habits, but it should not cause major changes in bladder or bowel control.
Seek urgent assessment (A/E same day) if you notice:
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Difficulty starting urination
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Inability to empty the bladder fully
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New urinary retention
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New loss of bladder or bowel control
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New loss of awareness of needing to pass urine or open your bowels
These symptoms are uncommon, but important, and may indicate serious nerve involvement.
3) Altered Sensation in the “Saddle” Area
The “saddle area” refers to the region that would contact a saddle: the inner thighs, groin, genitals, and the area around the anus.
Urgent assessment is required (A/E same day) if you experience:
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New numbness or reduced sensation in this area
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A marked change in sensation when wiping after using the toilet
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Unusual numbness around the genitals or inner thighs
This is not a normal feature of routine sciatica.
4) Severe Symptoms Affecting Both Legs
Sciatica is most commonly one-sided. I’ve written a blog explaining why this is the case if you’d like to understand it in more detail. Symptoms affecting both legs are far less common, and you should seek urgent assessment—particularly if pain, numbness, or weakness extends below the knee on both sides—if you develop:
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Significant symptoms in both legs (especially with weakness)
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Rapid deterioration in walking ability
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Severe bilateral numbness or loss of coordination
5) “Systemic” Symptoms or Serious Illness Context
While less common, urgent review is also appropriate if sciatica-type symptoms occur alongside:
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Fever, chills, or feeling acutely unwell
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Unexplained weight loss
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A history of cancer
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Recent significant trauma
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Immunosuppression or intravenous drug use
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Recent urinary tract infection (potential discitis)
These don’t mean something serious is definitely present — but they change the level of concern and warrant medical evaluation.
Why These Red Flags Matter
These features are uncommon, but they are important to recognise because their presence changes the priority from “how do we settle symptoms?” to “do we need urgent investigation to protect nerve function?”
If you are unsure whether a symptom counts as a red flag, it is safer to seek medical advice IMMEDIATELY
This information is not intended to alarm — it’s here because clear guidance is part of safe, evidence-based care.
Prognosis: What Most People Can Expect
While sciatica can be severe and disruptive, the overall outlook is generally favourable. Most people experience meaningful improvement over time, particularly when symptoms are understood and managed appropriately.
Recovery does not always follow a straight line. Symptoms often fluctuate, especially in the early stages, and this does not necessarily indicate worsening damage. Factors such as activity levels, movement habits, load, sleep, stress, and general health all influence how symptoms behave.
For the majority of people, sciatica does not require invasive treatment. Even when symptoms initially feel intense, long-term nerve damage is uncommon. Understanding what is driving symptoms — and responding proportionately — is usually more helpful than rushing into intervention.
Assessment by a practitioner with specific spinal expertise can help identify the most relevant contributing factors, provide appropriate reassurance, and determine whether further investigation is genuinely required.
A word of warning for those seeking private therapy input. You rarely need to be seen more than once a week, and even this regularity should be for a very short period of time. Remember that most of the time it is mother nature who works the magic, as physios we are here to help and not force and if you get better after 8 weeks of intense therapy just ask yourself, was it the intense physio or was it the initial advice, self care and time that worked???????
Treatment: Why Assessment Comes First
Because sciatica can arise from different underlying mechanisms, there is no single treatment that suits everyone. Approaches that help one person may be ineffective — or even counterproductive — for another.
For this reason, treatment recommendations should only follow a proper assessment. Understanding whether symptoms are more likely to be spinal, peripheral, load-related, or influenced by movement patterns allows care to be targeted rather than generic.
In practice, management often focuses on education, appropriate activity modification, restoring movement confidence, and gradually reintroducing load where needed. The exact approach depends on how symptoms behave, how they change over time, and what matters most to the individual.
Sciatica FAQs
1. What is sciatica?
Sciatica describes a pattern of symptoms caused by irritation of the sciatic nerve. This typically includes pain, altered sensation, pins and needles, or weakness travelling from the lower back or buttock down into the leg. It is not a diagnosis and does not explain the underlying cause on its own.
2. Is sciatica the same as a slipped disc?
No. A slipped disc is one possible cause of sciatica, but it is not the only one. Sciatic-type symptoms can arise from several different conditions, both within and outside the spine. Treating sciatica as if it automatically means a disc problem can be misleading.
3. Does sciatica mean nerve damage?
Not usually. Sciatic symptoms can be severe and distressing, but pain intensity does not reliably indicate permanent nerve damage. In many cases, the nerve is irritated or sensitised rather than permanently injured, and symptoms improve with appropriate management.
4. Can sciatica come from somewhere other than the spine?
Yes. Although some causes originate in the spine, sciatic-type symptoms can also arise from irritation along the course of the nerve outside the spine. This may include issues in the buttock or hip region, such as altered load tolerance, muscle sensitivity, or movement-related factors.
5. What is piriformis syndrome?
Piriformis syndrome is a term sometimes used to describe sciatic-type symptoms thought to arise from the deep buttock region rather than the spine. It remains a debated diagnosis, but it reflects the broader point that not all sciatica comes from spinal structures.
6. Do I need a scan if I have sciatica?
Not always. Imaging is not routinely required for sciatica and often does not change treatment, particularly in the early stages. Scans are usually considered when symptoms are severe, worsening, not improving as expected, or when there are features that raise concern about more serious conditions.
7. How long does sciatica usually last?
The course of sciatica varies depending on the underlying cause and the individual. Many cases improve over time with appropriate management. Some symptoms fluctuate, while a smaller number persist and require further investigation. Recovery is not determined by the label alone.
8. When should I worry about sciatica?
Urgent assessment is needed if sciatica is accompanied by rapidly worsening weakness, significant changes in bladder or bowel control, or altered sensation around the saddle area. These features are uncommon, but important to recognise.
9. What helps sciatica improve?
What helps depends on why the symptoms are present. Management is guided by assessment and may include education, reassurance, activity modification, and structured rehabilitation. There is no single approach that suits everyone, which is why understanding the cause matters.
10. Can sciatica be treated without surgery?
Yes. Most people with sciatica do not require surgery. Conservative management is effective for many, particularly when treatment is guided by a clear understanding of the symptom pattern and contributing factors. Surgery is considered only in specific situations.
Why You Should Choose Chris Heywood Physio
The most important thing when seeking help is finding a practitioner you trust—someone who is honest, responsible, and clear about your diagnosis, the treatment you really need, and whether any follow-up appointments are necessary.
I’m not here to poach you from another therapist, but if you’re looking for a new physiotherapist in Northamptonshire or simply want a second opinion, here’s why many people choose to work with me (read my reviews):
Over 25 Years of Experience & Proven Expertise
With 25+ years of hands-on physiotherapy experience, I’ve built a trusted reputation for clinical excellence and evidence-based care. My approach combines proven techniques with the latest research, so you can feel confident you’re in safe, skilled hands.
Longer Appointments for Better Results
No two people—or injuries—are the same. That’s why I offer 60-minute one-to-one sessions, giving us time to:
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Thoroughly assess your condition
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Provide focused, effective treatment
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Explain what’s really going on in a clear, simple way
Your treatment plan is tailored specifically to you, aiming for long-term results, not just temporary relief.
Honest Advice & Support You Can Trust
I’ll always tell you what’s best for you—even if that means you need fewer sessions, not more. My goal is your recovery and wellbeing, not keeping you coming back unnecessarily. I have low overheads nowadays and I do not have pre-set management targets to maximise patient 'average session per condition' (yes it does happen commonly and I hate it with a passion - read my article here)
Helping You Take Control of Your Recovery
I believe the best outcomes happen when you understand your body. I’ll explain your condition clearly, give you practical tools for self-management, and step in with expert hands-on treatment when it’s genuinely needed.
Looking for a physiotherapist who values honesty, expertise, and your long-term health?
Book an appointment today and take the first step towards feeling better.
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On a Monday and Tuesday I work as a advance musculoskeletal specialist in primary care but I can still be contacted for enquiries. You are welcome to call but it is often faster for me to reply via an email or watsapp message, simply as my phone will be on silent in clinic. Either way, I will reply as soon as possible, which in the week, is almost always on the same day at the latest.
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