Why the Biopsychosocial Model Matters in Persistent Pain

When we learn about pain in physio school, we learn about the biopsychosocial model. The model was proposed by George Engel in 1977 as an alternative to the dominant biomedical model (Engel, 1977).

The biomedical model essence is mechanical - identify the structural issue - fix or replace the problem part - then the person will feel better. It is similar to how mechanics fix cars.

The biomedical model works reasonably well when the issue is largely a tissue issue. If the problem was caused by physics, then physics is a good way to fix it.

Surgeons fixing a badly broken thigh bone after a car accident by putting in a big nail to stabilise the bone is a good example.

Where the biomedical model struggles

The biomedical model runs into issues, however, when it comes to persistent pain. Persistent pain can result largely from structural issues (see -> Primary vs Secondary Persistent Pain: What’s the Difference and Why It Matters). However, the tissue issue is commonly not enough in isolation to explain the pain. Sometimes people develop pain without a clear physical injury that started it.

We also know, for example, people can have many tissue changes in the back and have no pain (see -> Disc Bulges Don't Always Mean Pain: What the Science Really Says). That doesn’t mean the tissues are irrelevant. It means they are only one piece of the puzzle.

Breaking down the Bio-Psycho-Social Model

The ‘Bio’

Refers to tissue issues, like damage to muscles, tendons, bones and nerves but also to more general biology including physical activity, diet, sleep and whether there is body wide inflammation or hormonal changes that may be influencing the pain.

The 'Psycho'

Refers to classical mental health conditions like anxiety and depression, but also beliefs, thoughts and emotions around pain.

For example, someone who strongly believes their back pain is caused by cancer is very unlikely to experience a reduction in their pain until they have been adequately assessed by a healthcare professional and had their concerns confirmed or (hopefully) relieved. The key point to grasp here is is that pain may be high because of the belief, regardless of whether the person actually has cancer or not.

That is why accurately understanding your pain is so important. Misunderstanding it can actually increase it.

The 'Social'

Refers to close interpersonal connections: friends, family members, romantic relationships and work relationships all have the potential to influence pain, either for better or for worse. A supportive friend may lend an ear (more likely two) for some much needed stress relief. They may encourage engagement with your physiotherapy exercises as they recognise these seem to help. An unhelpful colleague may tell you your pain is 'not real', 'all in your head' or provide suggestions based on their experience with pain, failing to recognise the pain you are experiencing is very different.

The Trap

The trap people can fall into is when they fail to consider all aspects of the model.

Admiral Ackbar Avoids Neglecting Parts of The Biopsychosocial Model

Focusing only on psychology or social factors can mean important biological causes are missed. Someone may suffer with anxiety and have many unhelpful social connections and still have an underlying biological cause for their symptoms. If that person has chest pain and breathlessness for example, they may be having a panic attack, but they may also be having a heart attack. Focusing only on biological factors can mean important psychological and social factors are missed. Someone may have long term severe lower back pain with mild osteoarthritis and disc changes and still have underlying psychological and social drivers for their symptoms. If these psychological and social factors are never explored, the person may remain confused as to why their symptoms are so severe even though the structural changes in their back are mild and common in people with no pain.

Note

In reality, separating the biological, psychological, and social is impossible. They are deeply interconnected.

We use these categories simply because they make things easier to think about.

Bringing it Together

Persistent pain is caused by a combination of biological, psychological and social factors.

Part of the rehab process is teasing out which biopsychosocial factors drive pain up and which factors calm pain down, specifically for you! Everyone will have different dispositions, which is why pain treatment must be tailored to the individual.

Biopsychosocial Pain Pattern Tracker

Understanding pain is one thing. Figuring out what’s driving your pain is another.

A simple way to start is by tracking patterns over time.

I’ve created a minimalist biopsychosocial pain tracker to help you do exactly that.

You can download it for free below and start using it today.

Biopsychosocial Pain Pattern Tracker.docx

Download DOCX • 10KB

References

Engel, G. L. (1977). The need for a new medical model: a challenge for biomedicine. Science, 196(4286), 129-136.