Taking an accurate history is the most important part of the initial consultation when one is dealing with any medical or surgical problem. Unfortunately, when the mechanical lesion is involved there is still lack of understanding regarding the nature of the questions that should be asked, the reasons for asking them, and the conclusions to be drawn from the answers.
I will set out step by step the stages that should be developed in history taking, and the questions that should be asked at each stage. Practitioners will already have their own method of history taking, and I do not suggest at all that they should alter their routine. However, I believe that the following questions must be included, if one is to reach a conclusion following the examination of patients with mechanical low back pain.
As well as the usual questions regarding name, age and address, one should enquire as to the occupation of the patient, in particular his position at work which provides us with the most important and relevant information. Managers are not always sitting down as we tend to believe, and postmen are not always walking.
Where is the present pain being felt?
We need to know all the details about the location of the pain, because this will give us some indication of the level and extent of the lesion and the severity of the condition. If there are any associated symptoms such as anaesthesia, paraesthesiae and numbness, their location must be noted as well. Referred pain indicates that derangement is likely.
Because the location of the pain can change rapidly and dramatically, we must find out if the pain has been present on the same site or sites since the onset. At this stage we must determine whether the symptoms are central, bilateral or unilateral in origin, as this is an important factor in the classification of the patient and consequently in his treatment. Bilateral symptoms indicate a central origin, whereas central symptoms cannot arise from a unilateral structure.
How long has the pain been present?
It is important to find out whether we are dealing with an acute, a subacute or chronic condition. In recurrent low back pain we are not interested in an answer based on the length of time since the first attack; at this stage of the examination we want to know how long the present episode has been evident.
If the symptoms have been present for any length of time, as is often the case, we must find out whether the patient feels that his condition is improving, stationary or worsening.
The length of time that the condition has been present may assist us to determine the stability of healing following a disc prolapse. It may also indicate the development of dysfunction which is likely to occur following trauma or derangement. The longer the symptoms have been present, the greater are the chances that adaptive changes have taken place.
The length of time that the patient has had symptoms can also guide us in deciding how vigorous we can be with our examining procedures. If a patient has had his symptoms for several months and has been able to work all this time, he will probably have placed more stress on the joints at fault than we are likely to do during the examination, which means that we can be fairly vigorous. If on the other hand the patient had a sudden onset of pain within the past two weeks, we could be dealing with a derangement situation and may well increase the degree of derangement with out test procedures which, if applied too vigorously, may significantly worsen the condition of the patient. Generally speaking, if the condition has been present only for a few days to two or three weeks, we must take great care in handling and exercising the patient; but if the present pain has been evident for months, we can be rather vigorous with our procedures.
How did the pain commence?
Basically we want to find out if there was an apparent or no apparent reason for the onset of the pain. Most of the histories commonly state that the pain appeared for no apparent reason. Two of every three patients fall into this category, and only one patient will recognise a causative strain.
If pain has arisen for an apparent reason a recognisable strain has caused the symptoms — for example, an accident, a sports injury, lifting. If the patient was involved in an accident — for example, if he were struck by a bus, — he may have sustained multiple injuries and the mechanics of none of these would be clear. This type of patient must be treated gently and with caution.
If pain has arisen for no apparent reason, a derangement or dysfunction has developed during the course of normal living usually without the application of any external force. Strains arising in this fashion can under most circumstances be avoided by modification of the patient’s daily living habits or movements. However, if the pain commenced for no apparent reason and is gradually and insidiously worsening, we may well suspect serious pathology, particularly if the patient feels or looks unwell at the time of interrogation. It is always better to suspect the worst and be wrong, than to overlook the worst and be wrong.
Careful evaluation of the patient’s information regarding the onset of his symptoms is necessary in order to avoid faulty conclusions. There are situations in which the patient thinks that his pain commenced for no apparent reason, whereas we may recognise a causative strain; alternatively the patient may wrongfully relate the onset to certain activities in an attempt to find a cause for his low back pain, which in fact appeared for quite different reasons.
Is the pain constant or intermittent?
This is the most important question we must ask patients with low back pain. If in patients referred for mechanical therapy the pain is found to be constant, it usually is produced by constant mechanical deformation. However, we must keep in mind that constant pain can also be caused by chemical irritation. Intermittent pain is always produced by mechanical deformation.
Constant chemical pain:
This is present as long as chemical irritants are present in sufficient quantities and occurs in inflammatory and infective disorders and in the first ten to twenty days following trauma. Chemical pain following trauma reduces steadily as healing takes place. Chemical irritants do not appear and disappear during the course of the day. Therefore, pain of chemical origin is always constant, and patients who describe periods in the day when no pain is present must have intermittent pain which is of mechanical and not of chemical origin.
Mechanical stresses that would normally be painless, can become painful where chemical irritation has raised the threshold of excitation of the nociceptive receptors. Thus, movements may superimpose mechanical forces on an existing chemical pain and enhance it, but they will never reduce or abolish chemical pain. This is significant in the differentiation between chemical and mechanical pain.
Low back pain caused by chemical irritation is comparatively easy to identify, as the pain is usually constant and no mechanical means can be found to significantly reduce it. Five days of treatment and observation should be sufficient to arrive at this conclusion.
Constant and intermittent mechanical pain:
This is present as long as mechanical stresses are sufficient to cause mechanical deformation. This type of pain will frequently reduce or even disappear when movements or positions are adopted that sufficiently reduce the mechanical stresses. On the other hand, the mechanical stresses may as easily be increased by movements and positions. Constant mechanical pain will vary significantly in intensity but never disappears, whereas intermittent mechanical pain appears and disappears according to circumstances.
Constant pain must be truly constant — that is, there is no time in the day when pain or aching is not present. Pain must be classified as intermittent even if there is only half an hour in the day when the patient feels completely painfree. In that half hour there is no mechanical deformation present, and we must examine the circumstances in which the patient is painfree and utilise this information for treatment purposes. It is much simpler to treat a patient who has intermittent pain than one whose pain is constant and in whom mechanical deformation is present under all circumstances.
It is my observation that about seventy percent of low back pain patients have intermittent pain, and the remaining thirty percent have truly constant pain. The majority of patients with constant mechanical pain are likely to belong to the derangement category. Derangement alters the tension in the structures about the segment involved, increasing mechanical deformation in some tissues and decreasing it in others. The constant increase in tension produces constant pain which continues, until the tension is decreased by reduction of the derangement or adaptive lengthening of surrounding tissues.
Intermittent pain is relatively easy to treat, because if there is one hour in the day when no mechanical deformation is present, it is possible to gradually extend that painfree time period. Constant pain is rather a different problem and is more difficult to treat. The percentage of patients failing to respond to treatment is higher in the constant pain group than in the intermittent pain group. Generally speaking, the derangement syndrome can be associated with constant pain, whereas the postural and dysfunctional syndromes are characterised by intermittent pain.
What makes the pain worse? and What makes the pain better?
We must specifically ask about sitting, standing, walking, lying, and activities which involve stooping or prolonged stooping. In these positions the joint mechanics of the lumbar spine are relatively well understood, and therefore we will be able to determine which situations increase and which decrease mechanical deformation. We must carefully record any position or activity reported to reduce or relieve the pain, as we will utilise this information in our initial treatment.
In relaxed or prolonged sitting the lumbar spine falls into full flexion, the effects of which are described in detail elsewhere. If a patient tells us that sitting increases his symptoms, we know that sustained flexion causes mechanical deformation of his lumbar spine. But if a patient finds relief in sitting, flexion actually reduces the mechanical deformation.
Standing, expecially relaxed standing, places the lower lumbar spine in full end range extension which means that certain structures are on full stretch. If a patient tells us that he is worse in relaxed standing, sustained maximum extension produces mechanical deformation of his lower lumbar spine. But if a patient finds relief in relaxed standing, sustained maximum extension reduces the mechanical deformation.
Walking accentuates extension — that is, it further increases the lordosis of the lumbar spine as the hind leg by its backward movement brings the pelvis into forward inclination. If walking produces or increases pain, extension must produce or increase mechanical deformation of the lower lumbar spine. But if the patient has no pain in walking, extension is reducing the mechanical deformation.
There are basically three positions which may be adopted while lying: prone, supine and side lying. The many variations of these, caused by different leg positions, make evaluation of the effects of lying rather difficult. Apart from the lying position itself, the effects on the lumbar spine depend on the nature of the surface on which one lies — usually the mattress and its supporting base — which may be firm and unyielding, or soft and giving.
The effects of the three basic positions on the lumbar spine can be summarised as follows:
- (a) In lying supine on a firm surface the lumbar spine falls into extension, whereas on a soft surface the degree of extension is decreased and in some cases flexion may be produced.
- (b) In lying prone on a firm as well as a soft surface the lumbar spine is always placed near or at full end range of extension.
- (c) In side lying the lumbar spine is brought into side gliding towards the side one is lying on, more so when on a soft surface than on a hard surface.
Activities which involve bending:
In bending or prolonged bending the lumbar spine falls into full flexion and added to this are gravitational stresses. If, for example, gardening produces pain, sustained flexion must produce mechanical deformation of the lumbar spine.
But if the pain is reduced while gardening, sustained flexion stops the mechanical deformation.
Patients who have had pain for a long time, may have difficulty in determining what makes their pain better or worse. They are no longer able to observe objectively their own pain patterns because of the length of time the pain has been present. It is necessary to spend extra time to extract detailed information regarding the pain behaviour, because without this we cannot proceed to an adequate conclusion and appropriate treatment.
Occasionally a patient will tell us that there is no position or movement which affects the pain. In this case the information obtained from the history is insufficient, and during the examination we must try to produce a change in the patient’s symptoms by utilising extremes of movement or sustained positions.
Have there been previous episodes of low back pain?
We should enquire about the nature of any similar or other low back pain episodes, the time span over which they occurred, and their frequency. At this stage we should also find out about previous treatments and their results. Episodic history indicates derangement. Dysfunction is likely to develop insidiously after each episode and will now coexist but be masked by the present disturbance. Its presence will be revealed after resolution of pain resulting from the derangement.
- pain on cough / sneeze?
- disturbed sleep?
- pain on arising in the morning?
- recent X-Rays? — results?
- on medication at present?
- on steroids, in past or at present?
- general health? — recent weight loss?
- major surgery or accident, recently or previously?
- saddle anaesthesia? — bladder control?
Information gained from these questions may complete the picture of the condition we are dealing with. The reasons for asking these questions are obvious and straight forward, and they will not be discussed in detail.
Although the referring medical practitioner will almost certainly have excluded any serious or unsuitable pathology, we must remain alert for its presence.