Lower Back Pain: What Causes It and When Should You Get Assessed?
Lower back pain is usually caused by muscle strain, stiff joints or poor alignment, not serious disease. Most episodes settle within weeks. But if your pain keeps coming back, or gets worse when you stand or walk, the problem may be how your whole body spreads its load. A standing, weight-bearing scan can show alignment problems that lying-down scans miss.
Key points
- Lower back pain is extremely common and rarely a sign of something dangerous.
- The pain often comes from alignment problems elsewhere in the body, not just the lower back itself.
- Standard scans are done lying down. This relaxes the muscles and can hide alignment faults that appear under body weight.
- A standing whole-body EOS scan captures your skeleton under natural load, from head to feet.
- If you have numbness, weakness, or loss of bladder or bowel control, get urgent medical help.
What is lower back pain and why is it so common?
Lower back pain is discomfort felt anywhere between the bottom of your ribs and the top of your legs. It is one of the most common reasons adults see a doctor, and most people will have it at some point.
Your lower back (the lumbar spine) carries most of the weight of your upper body. It depends on good alignment in the parts above and below it. Your pelvis, hips, knees and even your feet all affect how load travels through your lumbar spine. When something is out of balance anywhere in this chain, your lower back often takes on the extra work.
That is why lower back pain so often comes back. If the real cause is a tilted pelvis, uneven leg length or a shift in your hip alignment, treating the lower back alone may not be enough.
What does lower back pain feel like?
Lower back pain can show up in many ways. The pattern of your symptoms can give clues about what is going on.
A persistent ache that gets worse after sitting or first thing in the morning.
Discomfort that increases with weight-bearing activity, then eases when you sit or lie down.
A sudden jolt after bending, lifting or twisting, sometimes with muscle spasm.
Pain that comes and goes over months or years, and never fully goes away.
What causes lower back pain?
Most lower back pain has mechanical causes. This means the way the parts of your spine and pelvis move and bear weight. Serious underlying conditions are uncommon.
Overuse, awkward lifting or long periods of sitting can overload soft tissues.
A pelvic tilt, a difference in leg length or a shifted centre of gravity adds uneven load.
Age-related changes in the joints and discs of the lumbar spine (spondylosis).
Slouching, desk work or standing for long periods in a poor position over months or years.
An important point many people miss: your lower back pain may not start in your lower back at all. Your body works as a connected chain. If your pelvis tilts, one hip is stiff or one leg carries more weight, your lumbar spine makes up for it. Over time, this leads to pain. That is why scanning only the painful area can miss the real problem.
When should you worry about lower back pain?
Most lower back pain is not dangerous. However, some symptoms need urgent medical attention. If you have any of the following, contact your doctor or go to an emergency department straight away.
- Numbness or tingling in your groin or between your legs (saddle area).
- Loss of bladder or bowel control.
- Sudden weakness in one or both legs.
- Severe pain after a fall or injury.
- Unexplained weight loss along with back pain.
These are rare, but they do need immediate assessment. For lower back pain that persists or keeps returning without these red flag symptoms, an alignment assessment can help you understand what is driving the problem.
How is lower back pain assessed with a standing scan?
Most scans for lower back pain are done while you lie down. X-rays, CT and MRI all capture your body in a relaxed position, with no load on it. That means your muscles are not working, gravity is not acting through your spine, and any alignment faults that only appear when you stand may be hidden.
An EOS scan works differently. You stand naturally in the machine while it captures your whole skeleton from head to feet in a single image. This shows exactly how your spine, pelvis, hips, knees and ankles line up under your own body weight.
Because the EOS system uses about 90% less radiation than a standard X-ray, around ten times less, it is comfortable for routine use. The scan itself takes only a few seconds while you stand still.
Your results show how each part of your body adds to (or takes away from) the support of your lower back. This can change the whole direction of your treatment, because it shows problems a scan of one area would miss.
When MRI is the better choice: EOS is excellent at showing bone alignment, joint position and overall posture under load. If your clinician suspects a disc problem, nerve compression or a soft-tissue injury, MRI is usually the more suitable tool. The two types of scan answer different questions, and in some cases both are useful.
What is the best way to relieve lower back pain?
Staying active is one of the most consistently supported approaches. Bed rest for more than a day or two tends to make things worse, not better. Gentle walking, swimming and targeted core exercises are generally recommended by the NHS in the UK and most orthopaedic guidelines.
However, if your pain keeps coming back, general exercise alone may not be enough. This is where understanding your alignment matters. If a pelvic tilt or hip imbalance is loading your lower back unevenly, a physiotherapist or surgeon can make a more targeted plan once they can see the full picture.
ScanAlign does not provide treatment. It provides the diagnostic imaging that helps your treating clinician understand the underlying cause. You do not need a referral from your doctor, and you can share your results with any specialist.
Before you start a treatment, or change the one you are on, it is worth getting a detailed diagnosis. Knowing whether the cause sits in your pelvis, your legs or your spine changes what will actually help.
Wondering whether your lower back pain could be an alignment problem? A free video consultation with our team can help you decide if travelling to London for a standing scan is the right next step.
Book a free video consultationFrequently asked questions about lower back pain
Standing loads your lumbar spine differently from sitting. If your pelvis, hips or legs are slightly out of alignment, gravity increases the uneven stress on your lower back when you are upright. This is exactly the kind of problem a standing whole-body scan is designed to show.
Yes. A tilted pelvis, a stiff hip joint or uneven leg length can force your lumbar spine to compensate. This leads to pain in your lower back rather than at the original source. Whole-body imaging helps find these connected causes.
An EOS scan captures your whole skeleton in a single standing image. Because you are upright and bearing your own weight, it shows how your spine, pelvis, hips and legs line up under natural load. This can uncover alignment problems that lying-down scans miss. Learn more about how an EOS scan works.
Yes. The EOS system uses about 90% less radiation than a standard X-ray, around ten times less. You can find more detail on our FAQs and safety page.
No. ScanAlign accepts self-referrals. You can book directly without seeing your doctor first.
The price for patients travelling from abroad is confirmed during the free video consultation, and you can read more on our FAQs page. This free consultation before booking helps you understand whether a scan is the right step for you.
When you lie down, gravity is taken away and your muscles relax. Alignment faults that only appear under your own body weight may straighten out on the table. So the image looks normal, even though your pain is real.
Usually not. Lower back pain when standing is most often caused by mechanical alignment or posture problems. However, if you also have numbness, weakness in your legs, or any loss of bladder or bowel control, get urgent medical help from your doctor or an emergency department.
EOS is excellent for bone and joint alignment, but it does not show soft tissues such as discs or nerves in detail. For suspected disc problems, MRI is usually the better choice. In some cases both scans give useful information that complements each other.
Stay gently active, avoid long bed rest, and use over-the-counter painkillers if needed. If the pain does not improve within a few weeks, or if it keeps coming back, an alignment assessment may help find the underlying cause. If you have red flag symptoms such as numbness, weakness or loss of bladder or bowel control, get medical help immediately.
Find out what is really behind your lower back pain
A free video consultation with our team will help you decide if a standing whole-body scan in London is the right next step.
Book a free video consultationWritten by Abbas Dhami (Specialist Diagnostic Radiographer)
Sources
- NHS. "Back pain." nhs.uk, 2023. Overview of causes, self-care and when to seek help.
- National Institute for Health and Care Excellence (NICE). "Low back pain and sciatica in over 16s: assessment and management." NICE guideline NG59, 2016 (updated 2020).
- Illés T, Somoskeöy S. "The EOS imaging system and its uses in daily orthopaedic practice." International Orthopaedics (SICOT), 2012; 36(7): 1405-1411.
This page is general information and not a diagnosis.
ScanAlign is the trading name of CoreMed Solutions Ltd and operates under The Harley Street Hospital's CQC licence.