Investigations in musculoskeletal health

Many people expect a scan or blood test when they develop joint, muscle, or back pain. In reality, most musculoskeletal problems can be diagnosed clinically and improve with time, movement, and rehabilitation.

Investigations are used selectively. Their role is to clarify diagnosis, rule out serious conditions, or guide management when results are likely to change the treatment plan.

This page explains how GPs decide whether investigations are needed, what different tests are used for, and the role of scans in a holistic assessment.

These articles are intended as educational sources, not diagnostic nor taking place of a proper medical assessment. If you need help with ongoing joint concerns, please book a GP appointment.

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How a GP decides whether investigations are needed

A GP bases the decision to request tests on the overall clinical picture, not just pain severity.

Investigations may be considered when:

Symptoms are persistent or worsening despite appropriate management
There are red flag features suggesting serious pathology
Pain follows significant trauma
There are neurological symptoms such as weakness or numbness
Inflammatory or systemic disease is suspected
The diagnosis remains unclear after assessment

Seek urgent medical advice if you develop:

Loss of bladder or bowel control
Progressive weakness or numbness in the arms or legs
A hot, swollen joint with fever
Severe pain following significant trauma
New severe pain with feeling acutely unwell

These symptoms may indicate serious conditions requiring same day assessment.

Common musculoskeletal investigations and their role

X-ray

X-rays are useful for assessing bones and joint structure. They are most helpful for:

Suspected fractures
Advanced osteoarthritis
Joint alignment problems

X-rays do not show muscles, tendons, discs, or early inflammatory changes well.

Ultrasound

Ultrasound is commonly used to assess soft tissues. It may be helpful for:

Tendon injuries or tears
Shoulder problems such as rotator cuff issues
Bursitis or fluid collections
Some joint effusions

Ultrasound findings must be interpreted alongside symptoms, as abnormalities can exist without pain.

MRI

MRI provides detailed images of soft tissues, discs, nerves, and joints. It may be considered for:

Persistent back or neck pain with nerve symptoms
Suspected serious spinal pathology
Pre-surgical assessment
Complex or unclear cases

MRI is not routinely needed for early back or joint pain, as many findings are age related and do not explain symptoms.

Blood tests

Blood tests are used when inflammatory or systemic causes are suspected. They may help assess:

Inflammatory arthritis
Autoimmune conditions
Infection in selected cases

Blood tests are not usually required for mechanical joint pain, osteoarthritis, or muscle strain.

Important limitations of scans and tests

It is common for scans to show changes that are not the cause of pain. Examples include disc bulges, degenerative changes, or tendon abnormalities that are also seen in people without symptoms.

For this reason:

Test results are interpreted alongside clinical assessment
A “normal” scan does not mean pain is not real
An “abnormal” scan does not always require intervention

Over-investigation can sometimes increase anxiety and delay recovery.n.

How investigations guide treatment

IWhen used appropriately, investigations can:

Confirm or exclude serious conditions
Support referral decisions
Guide targeted treatment
Provide reassurance when serious causes are ruled out

However, many effective treatments, including physiotherapy and rehabilitation, can begin safely without tests.

Expert physio insights by AccessGP Lead Physiotherapist, Sonali Talwar

Sonali is an experienced physiotherapist working with AccessGP. In her clinical practice, recovery often depends more on restoring movement, strength, and confidence than on scan findings.

Imaging can be useful in selected cases, but it is rarely the starting point for rehabilitation. A structured programme based on symptoms and function often leads to meaningful improvement even when scans show degenerative changes.