Waddell’s tests in relation to pain assessment in personal injury claims

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Personal injury solicitor James McNally advises caution when interpreting the results of Waddell’s tests.

The results of ‘Waddell’s tests’ in a medical report are always of interest to defendant personal injury lawyers. They hope that the tests will show the claimant to be a malingerer who is exaggerating their claim in the hope of a larger financial settlement.

However, the outcome of these tests is often misunderstood and the presence of abnormal illness behaviour or non-organic pain does not necessarily mean that the claimant is exaggerating.

Waddell’s tests and others like them therefore need to be carefully considered.

Illness Behaviour

Illness behaviour is a central theme running through Professor Gordon Waddell’s research, so in order to understand the significance of the tests themselves it is necessary to consider the concept of illness behaviour. As Professor Waddell himself states in his book “The Back Pain Revolution”, “illness behaviour is what people say and do to express and communicate that they are ill. It depends very much on what and how they think about their symptoms and their illnesses.”

Illness behaviour is perfectly normal. When ill we all exhibit it to some degree. However in some patients this illness behaviour can become out of proportion to the actual illness (or injury) and can be a reflection of their underlying psychological state. In these cases illness behaviour may result in the period of pain and suffering being prolonged and the condition itself possibly becoming aggravated.

Professor Waddell has noted that some medical practitioners take the existence of illness behaviour as an indication that there is nothing wrong with the patient. This is incorrect. Illness behaviour is a natural reaction. It is part of the way we communicate our pain and suffering. Waddell believes that for the most part illness behaviour reflects the severity of our underlying physical pain.

What are Waddell’s tests?

The tests were developed by Professor Waddell and others in a series of studies carried out in the 1980’s.

Initially Professor Waddell attempted to isolate back symptoms that were more closely associated with illness behaviour than physical illness. The symptoms were derived from a literature review and pilot studies at the Problem Back Clinic where he practiced. His study revealed more than 30 such symptoms.

He then questioned 20 spinal surgeons about these symptoms, asking them to indicate which ones they regarded as being physically inappropriate. Whilst this did not give Waddell any clear findings it did reveal a number of avenues to explore.

Reliability and comparative studies were undertaken. During this phase of his research a number of the symptoms were discarded due to rarity, the inability to reproduce them with different doctors or because they were common in a pain free comparative group.

Finally, Waddell distilled his group of 30 symptoms into 7 ‘non-anatomic’ symptoms:

  • Pain in the tip of the tailbone
  • Whole leg pain
  • Whole leg numbness
  • Whole leg giving way
  • Complete absence of any periods with very little pain in the last year
  • Intolerance of, or reactions to, many treatments
  • Emergency admission to hospital with simple backache

Waddell went on to document 7 behavioural signs which he describes as “non-organic signs or more precisely behavioural responses to examination.

  • Tenderness – This usually follows some anatomical pattern, but in the case of non-organic tenderness is often widespread. Tenderness falls into 2 categories:
  • A) Superficial tenderness, which is present when the lumbar skin is tender to light touch over a wide area. However nerve irritation can cause a band of local tenderness
  • B) Nonanatomic tenderness, which is deep tenderness over a wide area that crosses musculoskeletal boundaries.
  • Simulation – This gives the impression that a movement will cause pain whereas no such actual movement is taking place. There are 2 forms of simulation test:
  • A) Axial Loading. Initially, light downward pressure is applied to the top of the patient’s head, which can often produce physical neck pain. The test is then repeated by applying pressure on the patient’s shoulders. Professor Waddell found that low-back pain on this occasion was surprisingly rare, even when serious spinal pathology was present.
  • B) Simulated rotation. A rotated spine can also cause back pain, but when carrying out Waddell’s test the patient is asked to stand with their hands at their sides. The patient’s shoulders and pelvis are moved together so that they remain in the same plane. As a result no rotation of the spine is actually taking place, and if no rotation is taking place in the spine, then any report of low-back pain is an indication that it is a behavioural response. The test can also produce nerve-root pain if the patient has nerve irritation which is a physical response.
  • Distraction tests Professor Waddell states in his book that in its simplest (and also its most effective) form this test involves observing the patient at all times, not just when a formal physical examination is taking place. Any distraction tests should be non-painful, non-emotional and non-surprising. The most common form of distraction test is “straight leg raising”. This is part of most standard clinical examinations. Waddell’s view was that if “straight leg raising” was limited on the formal examination then a further attempt should be made at a later stage while the patient is distracted. Once again, the result of “straight leg raising” needs to be interpreted with caution. The test should only be treated as positive (ie demonstrating non organic illness behaviour) if there is at least a 40% change between formal and distracted “straight leg raising” due to a change in back lordosis and the position of the hips when the patient is lying down or sitting up.
  • Regional changes. These involve large parts of the anatomy such as the entire leg. These changes once again fall into 2 categories. A Regional weakness. This is characterised by a feeling of the leg “giving way” and involves several muscle groups in which normal muscle resistance suddenly collapses. B Regional Sensory Change. This is tested for by means of light touch and will involve a comparison with the other leg. Restrictions on Applicability of Waddell’s tests In The Back Pain Revolution, Professor Waddell makes clear that the tests he has highlighted are merely one aspect of the whole diagnostic process: “You must use [the tests] with care and compassion, and must not over interpret or misinterpret your clinical observations”. Professor Waddell has highlighted three particular situations where behavioural signs and illness behaviour cannot be used even if the patient exhibits multiple illness behaviours. These situations are:
  • Patients with possible serious spinal injury or widespread neurology.
  • Patients over the age of 60, (since such responses are more common in elderly patients).
  • Patients from ethnic minorities, (as there appears to be wide cultural variation in relation to pain behaviour.) The Waddell’s tests are not applicable to these groups as the illness behaviour exhibited differs from that highlighted in Professor Waddell’s original research. Further research into the illness behaviour of these groups is required.

Alternative tests

Are there any other tests that may be of use to determine a patient’s accuracy and truthfulness when reporting their pain and symptoms?

In 2002 the heel-tap test was developed by AW Blom et al of the Avon Orthopaedic Centre Bristol.. The advantage of the heel-tap test is that it is simple, quick and easy to perform unlike Waddell’s tests which if carried out thoroughly can be time consuming. According to Blom there is a very high degree of correlation between the findings in Professor Waddell’s tests and the outcome of the heel-tap test.

The test itself involves the patient sitting on an examination table with both the hips and knees flexed to 90°. The possibility that the test may cause lower back pain is explained to the patient. This is not true. The medical examiner then taps lightly on the patient’s heel with the base of his hand. If the patient indicates that they have experienced sudden low back pain then the test is regarded as positive and indicative of non organic pain.

When carrying out the research for the heel-tap test, the same medical examiners performed both the heel-tap test and the Waddell’s test on each patient. All examiners had similar results, as set out in the table

Correlation between Waddell’s signs and the heel-tap test in patients complaining of lower back pain.

Waddell’s signs     Number of patients     Heel tap test positive    Heel tap test negative

0 positive                                      22                                      1                                          21

1 positive                                        3                                       0                                          3

2 positive                                       2                                        0                                         2

3 positive                                       0                                        0                                         0

4 positive                                       1                                         1                                         0

5 positive                                      31                                      31                                         0

Blom’s conclusion was that there is a high degree of correlation between Waddell’s tests and the heel-tap test. However, the heel-tap test does not take us further forward in determining the truthfulness of the patient when describing their symptoms. as the authors of the study on the heel-tap test have themselves acknowledged:

“We stress that non-organic and organic pathology often occurs simultaneously. We would suggest the patients who are positive for the heel tap test should undergo further evaluations specifically looking for non organic pathology”.

Conclusion

Illness behaviour cannot be interpreted in isolation. Professor Waddell states in The Back Pain Revolution that medical practitioners must still carry out a full diagnostic triage and ‘not over-interpret isolated behavioural symptoms or signs” which he says:

“are quite common in normal people with straight-forward physical pathology and no other evidence of illness behaviour.Behavioural symptoms and signs are not medico-legal tests, but observations of normal human behaviour in illness. They do not necessarily mean that the patient is acting, faking or malingering. Most illness behaviour occurs in pain patients who are not in a compensation or adversarial legal situation.”

Whilst it is more straightforward and easier to perform the heel-tap test does not offer an adequate alternative diagnostic test, as the results mirror those for the Waddell’s tests.

It is therefore clear that the use of Waddell’s tests in a medico-legal setting is only appropriate if further investigations into non-organic causes of any reported pain and illness behaviour are to be carried out. A positive Waddell’s test does not indicate malingering and should not be over-interpreted. To do so is a misuse of this clinical research and contrary of the views of Professor Waddell himself.

Determining the truthfulness and accuracy of a claimant’s reported symptoms has always been an art rather than a science, but perhaps the next set of studies and tests will include input from personal injury practitioners from all sides of the debate, who are able to bring with them a wealth of experience and possibly much-used tests of their own.