United Kingdom House of Lords Decisions

Pickford v. Imperial Chemical Industries Plc [1998] UKHL 25; [1998] 3 All ER 462; [1998] 1 WLR 1189 (25th June, 1998)

LORD GOFF OF CHIEVELEY

My Lords,

      I have had the advantage of reading in draft the speech prepared by my noble and learned friend, Lord Hope of Craighead. For the reasons he has given, I would also allow this appeal.

LORD JAUNCEY OF TULLICHETTLE

My Lords,

      I have had the advantage of reading in draft the speech prepared by my noble and learned friend, Lord Hope of Craighead. For the reasons he has given, I would also allow this appeal.

LORD SLYNN OF HADLEY

My Lords,

      I have had the advantage of reading in draft the speeches prepared by my noble and learned friends Lord Steyn and Lord Hope of Craighead. They have set out the facts and the competing views so fully that it is not necessary to repeat them. I therefore summarise my conclusions.

      I accept that at the relevant time it was foreseeable to the employers that if employees typed for excessively long hours this might produce not only backache and eye strain but also a risk of cramp of the hand or repetitive strain injury. The fact that the present employers gave a warning and took special precautions in relation to their accounts department supports this.

      It seems to me, however, that on the evidence the trial judge was entitled to find that the plaintiff was not in the same position as staff in the accounts department. She was employed not just for typing but also for general secretarial work. True it is that she did sometimes type for 75 per cent. of the working hours particularly in April and May 1989 but she often typed for not more than 50 per cent. of the day, her other activities intervening. Some of those other activities she could, as I see it, arrange so as to break up her periods of typing and some of them would of themselves interrupt her typing. The plaintiff was clearly efficient and experienced and, albeit highly conscientious, was capable of avoiding and able to avoid excessively long periods of typing. I am not satisfied therefore that the employers were negligent in failing to give her warnings similar to those given to the accounts department which it is claimed should have been given to her or to so control her activities that she did not type for long consecutive periods.

      I differ with considerable hesitation from the majority in the Court of Appeal because of their great experience in cases of this kind and because of the complex interplay of medical evidence in the case. I am however satisfied for the reasons given by Swinton Thomas L.J. and by my noble and learned friend Lord Hope of Craighead that the trial judge was entitled to find that the plaintiff had not discharged the onus of proving, as it was necessary to prove, that the pain she suffered was organic in origin.

      It is obvious that the trial judge found this a difficult case, as it was, and I have considerable sympathy with the plaintiff as a conscientious and loyal employee. But at the end of the day I do not consider that it was open to the Court of Appeal to reject the judge's findings.

      I would therefore allow the appeal.

LORD STEYN

My Lords,

      A Deputy High Court Judge decided that a secretary's claim against her employers for what is commonly called repetitive stress injuries failed on the facts as he found them. It was not an easy case to try. And there is a presumption that a trial judge's conclusions on issues of fact are correct. But in agreement with the majority in the Court of Appeal [1997] I.C.R. 566 my view is that the trial judge's assessment of the evidence was fundamentally flawed. Moreover, on balance I am satisfied for the reasons so lucidly and trenchantly given by Stuart Smith L.J. (with whom Waite L.J. expressed agreement in a separate judgment) that the employee was entitled to succeed on liability.

      Since 1948 cramp of the hand or forearm due to repetitive movements such as typing has been classified as a prescribed disease for the purpose of industrial benefit. It is described as PDA4. The causative agent is still uncertain but the DSS Notes of 1983 state that it is "probably due to a combination of physical fatigue of muscles and an underlying psychoneurosis." It rarely occurs among typists. But the risk is known. Thus Imperial Chemical Industries Plc., the employer in the present case, had in place a system of warning and supervising intensive users of word processors in their accounts department at Macclesfield. But no warnings were given to the plaintiff, Miss Pickford, and the extent of her typing was not supervised. The employers assumed that she was not an intensive user of a word processor.

      By all accounts given by those who worked with her Miss Pickford was a diligent and conscientious employee. She was also an excellent and fast typist. In 1986 the typing content of her job was apparently about 50 per cent. But it was her case at trial that by November or December of 1988 typing was taking up as much as 75 per cent. of her time. It was then that she began to experience strange feelings in her hands by the weekend. That was her oral testimony. Her diary entries reflected the constant pressure of her typing load. Her entry of Tuesday, 23 May 1989, recorded that her hands "are almost seizing up when I do a lot of typing." It stated that "it started late last year when I notice that by Friday, my hands were tight and sore (I'd been typing flat out all summer to keep up with mounds of work, as well as my other jobs)." Her case was therefore based on the link between a sharply increased typing workload and the manifestation of those symptoms between November 1988 and May 1989 when she first took medical advice. What then followed is common grounds. Miss Pickford was advised to stop typing. She was therefore compelled to stop working as a secretary. And ICI did not offer her satisfactory alternative employment. In September 1990 ICI terminated her employment.

      Miss Pickford had an excellent work record. She was a conscientious and indeed dedicated employee. The judge found that she was not a malingerer. He also found that she was an honest and truthful witness. Yet he rejected the account given in her diary entry of 23 May 1989 to the effect that her symptoms had started in late 1988. He therefore also rejected her oral evidence which expanded on the diary entry but was to the same general effect. No matter how one strives to find a plausible explanation, which may support the reasoning of the Deputy High Court judge, I must confess that this particular decision confounds common sense. In her diary entry and oral evidence Miss Pickford could not possibly have made an honest mistake about the pressure of typing work and her symptoms over a period of six months immediately preceding her seeking medical advice. The judge came into a conclusion which lacks intellectual coherence. Plainly her diary entry of 23 May, made at a time when it is acknowledged she knew nothing about PDA4, was broadly speaking accurate and so was her oral evidence expanding on it.

      It follows that the judge misdirected himself in the assessment of Miss Pickford's evidence. A misdirection on one point does not necessarily justify a complete disregard of all the judge's findings of fact. Everything depends on the nature of the misdirection and the circumstances of the particular case. In the present case the misdirection was not on an isolated point of evidence. It related to the essence of Miss Pickford's case: if the evidence of Miss Pickford about mounting pressure of typing in late 1988 and early 1989, and the emergence of symptoms over six months, is rejected her case failed at the first hurdle. Moreover, the judge's finding had a domino effect: If the pressure of her typing did not increase as and to the extent that Miss Pickford testified, the emergence and continuance of her symptoms become more questionable. The judge's error led him to treat Miss Pickford as honest but inclined to exaggerate. It caused the judge to give inadequate effect to the picture of mounting typing pressure emerging from Miss Pickford's diary entries. Critically, it led him to accept only that Miss Pickford "from time to time may have typed up to the five hours." Leaving aside the fact that 75 per cent. of her working day was 5 hours and 40 minutes, the judge's findings materially understated the effect of Miss Pickford's oral evidence. In short the judge's error dragged down the whole of his conclusions of fact. His error disabled him from fairly assessing Miss Pickford's evidence.

      Much of the argument on the present appeal centred on the natural breaks from typing caused, for example, by Miss Pickford answering the telephone. This was a relevant matter. But this is how the judge approached the matter:

 ". . . while I accept that there were peaks and troughs and that at times the peaks may have seemed excessive in the plaintiff's perception, she had the necessary discretion, experience and knowledge, as she was well aware, to plan, organise, prioritise and negotiate the work and, if necessary, to seek help so as to enable herself to cope reasonably with it."

Again the judge fell into error. It was established at the at the trial that Miss Pickford was unaware of the risk posed by prolonged repetitive movements: she only became aware of that months after she first sought medical advice. It is therefore wrong to say that she had the necessary knowledge to prioritise her work. In any event, the alleviating effect of natural breaks was a matter of fact and degree upon which Miss Pickford's evidence was not accepted by the judge. And his relevant findings are directly linked with his earlier rejection of the diary entry of 23 May and oral evidence in support of it.

      The employers relied on an Australian expert, Dr. Lucire, who put forward the theory that Miss Pickford suffered from conversion hysteria. Miss Pickford's excellent work record was inconsistent with this theory. But more importantly it was proved at the trial that this medical phenomenon only arises where the individual has knowledge of the risks of repetitive strain injury. Miss Pickford had no such knowledge at the relevant time. Admittedly, the judge did not accept the conversion hysteria theory. On the other hand, he did not, as the evidence compelling required, find that it could be eliminated as a possibility. Had he done so the judge would have been bound to accept the opinion of Mr. Stanley (an orthopaedic consultant) and Dr. Hay (a consultant psychiatrist) that Miss Pickford's symptoms were largely (but not exclusively) due to an organic cause i.e. excessive typing. The argument of the appellants that the Court of Appeal reversed the burden of proof is wrong: the march of common sense reasoning, closely tied to the facts of the case, led to the Court of Appeal's conclusion.

      The judge found that Miss Pickford had PDA4. The contrary was not argued in the Court of Appeal or, after some hesitation, not before the House. That immediately raises the point that there must be an explanation for the fact that she contracted PDA4. What was the cause of her PDA4? There really was no alternative on the evidence to concluding that this condition was caused by Miss Pickford's typing work. No doubt there was also an underlying psychoneurotic cause but that does not affect the legal position. Unfortunately, the judge encountered conceptual difficulties. He said:

 ". . . I am disposed to find that she had a cramp of the hand, but I am not satisfied that it was due to the repetitive movements of typing in the sense that such movements were an effective cause of the cramp, as opposed to being merely the causa sine qua non. . . "

The judge concluded that the cramp in Miss Pickford's hand was associated with her work but not caused by it. He said that the typing was "only a causa sine qua non." This is not the first time that a judge has been led astray by a Latin tag. Plainly the judge thought that the typing contributed to Miss Pickford's cramp and it was therefore even on his own findings in causative terms a sufficient contributory cause.

      The judge was persuaded that Miss Pickford did not sustain "an illness or an injury or a lesion or a disease." This was a misconception. If Miss Pickford's oral testimony is substantially rejected as the judge did, her claim had to fail. But if the thrust of her case is accepted, viz that she sustained continuing systems which disabled her from continuing to type, then she plainly sustained a disability. Since at least 1948 the argument that PDA4 cannot ever be an injury can be dismissed as wholly unmeritorious.

      That leaves the issue of negligence to be considered. I must approach this aspect on the basis that there are compelling reasons for departing from the findings of fact of the trial judge and accepting the evidence of Miss Pickford as well as that of her expert witnesses. Nevertheless I have found this the most difficult issue in the case. On balance I am persuaded that, although the ICI had an excellent employment record, they culpably failed in this case to appreciate that Miss Pickford was carrying an enormous typing load and that she had in fact become an intensive user of the word processors. Her immediate supervisor failed to supervise the extent of her typing. Significantly, Dr. Lamb the defendant's medical officer did not know that secretaries did anything like as much typing as Miss Pickford did. She ought to have been given the warnings to take breaks and rest pauses like the typists in the accounts department. And, it seems to me that she should have been told why it was necessary and there should have been supervision of the extent of her typing.

      My Lords, amid all the tangled words and imperfect scientific insights afforded by the evidence in this case, the cumulative effect of the central proved facts establish that Miss Pickford's work caused her disability and that her employer's could, by the exercise of reasonable care, have avoided the occurrence of her disability.

      For these reasons I would dismiss the appeal.

LORD HOPE OF CRAIGHEAD

My Lords,

      The respondent was employed by the appellants as a secretary at the premises of ICI Pharmaceuticals at Macclesfield. She had worked as a secretary and typist elsewhere since 1970. She went to ICI in 1983 at first as a temporary secretary. In January 1984 she obtained employment there full time as the secretary to three section managers in the quality control department. She worked a seven and a half hour day from 10a.m. to 6p.m., with half an hour off for lunch. Among the various duties which she was expected to perform was typing work. At first she used an electric typewriter, but during 1984 she was provided with a word processor. In November 1986, when preparing a job assessment, she estimated that her typing work took up to 50 per cent. of her working time. Her other secretarial duties took up the remaining 50 per cent. Towards the end of 1988 and again in April and May 1989 there was an increase in the amount of her typing work. But she continued nevertheless to perform all her other duties as a secretary.

      On 25 May 1989 she went to see her general practitioner, Dr. Baker. She complained of pain in both hands, more in the right than the left. She told him that she had first noticed this about seven months previously. Dr. Baker could find no abnormality on examination, but he signed her off work for a short period. She was then seen by the works doctor, Dr. Lamb. He noted that the volume of typing seemed to be the problem, but he was unable to find any physical explanation for the pain in her hands. After further visits to Dr. Baker she was referred to a consultant orthopaedic surgeon, Mr. Auchincloss. He saw her on 14 September 1989. In his opinion the symptoms were work related, but they were impossible to treat and were not capable of pathological diagnosis.

      The respondent was not satisfied with the advice which she received from Mr. Auchincloss. He had told her that she could carry on typing and put up with it, or else seek alternative work. He said that he would not be seeing her again, as he had nothing to offer her. In September 1989 she wrote to the Repetitive Strain Injury Association, one of whose publications had been given to her by a work colleague. She asked them for information on repetitive strain and for the name of someone whom she might contact as an expert on this condition. On their recommendation she was seen thereafter by a number of specialists. Meantime in November 1989 she was signed off work as long-term sick. She returned to work in May 1990, but after three days' work including filing she left again due to pain in her hands. The appellants terminated her employment with them on 14 September 1990, as there was no work available for her for which she accepted she was fit.

      On 20 November 1991 she commenced proceedings against the appellants for damages. She claimed that by their negligence they had caused her to sustain repetitive strain injury. On 11 February 1994 her Statement of Claim was amended to allege that she suffered not from repetitive strain injury but from Prescribed Disease A4 (PDA4). Repetitive strain injury is a familiar expression, but medical experts agree that as a medical term it is unhelpful. It covers so many conditions that it is of no diagnostic value as a disease. PDA4 on the other hand does have a recognised place in the list. It was included in 1948 as a prescribed disease by the Department of Health and Social Security for the purpose of industrial injury benefit. It was described in the list of prescribed diseases in leaflet NI.2 which was issued by the Department of Health and Social Security in October 1983 in these terms:

 "Cramp of the hand or forearm due to repetitive movements: eg writer's cramp. Type of occupation--any occupation involving prolonged periods of hand writing, typing or other repetitive movements of the fingers, hand or arm: eg typists, clerks and routine assemblers."

      The appellant's case was that she had contracted the condition in the course of her employment with the appellants as a secretary. She maintained that it was PDA4, that it was organic in origin and that it was due to repetitive movements of her hands while typing. She said that it had been caused by the very large amount of typing which she had carried out on her word processor at speed for long periods of time without breaks or rest periods; that was reasonably foreseeable that typing at speed for long periods without breaks or rest periods might give rise to it; and that the appellants were negligent because they had failed to warn her of the risk of contracting the disease and of the need to take rest breaks.
 

      The trial was heard in the High Court by His Honour Judge Eifion Roberts Q.C. He heard evidence over a period of 10 days from a substantial number of expert and lay witnesses. Much of the medical evidence was directed to the question whether the condition was PDA4 and, if so, whether it was organic in origin. The medical issues were controversial, as the condition is such a mysterious one. There is a strong body of medical opinion to the effect that it is an organic condition, due to some kind of trauma or physical injury. There is another strong body of medical opinion that the basis of it is psychogenic, as the product of a somatisation--that it is all in the mind, in layman's terms. It was admitted that the condition is rare in typists. The appellants said that it had never occurred among typists on their premises. The ergonomic experts on each side were agreed that repetitive movements alone were unlikely to cause injury. And no pathology for the condition has yet been demonstrated. So the medical experts differed as to the basis of the condition generally and as to the cause of it in the respondent's case in particular. Much of the evidence from the lay witnesses was directed to the work which the respondent was doing in the performance of her duties as a secretary. The amount of the typing in comparison with her other duties was an important issue, especially in regard to the opportunity which this gave for natural breaks in her typing work.

      The judge held, after analysing the evidence, that the respondent had failed to establish that she was entitled to damages. In the course of a long and careful judgment he said that the most that he could find on the whole of the medical evidence was that the condition of cramp of the hand due to repetitive movements (PDA4) might have an organic cause or a psychogenic cause, or a combination of both causes or one cause to begin with and the other supervening. He was disposed to hold that the respondent had a cramp of the hand, but she had failed to satisfy him that its cause was an organic one. She had also failed to satisfy him that it was caused by her typing work, as opposed to being merely associated with it.

      He then asked himself whether it was reasonably foreseeable that a secretary who was typing to the extent which he had found established by the evidence would be likely to suffer from PDA4. He held that, while this was theoretically possible, it was not reasonably foreseeable. As for the breaches of duty which had been alleged, he did not think that it was incumbent on the appellants to specify rest pauses during the respondent's typing work. This was because she had ample scope to interpose her typing with her non-typing secretarial work. The work lent itself naturally to rotation and interspersment. It could reasonably have been expected that a person of her intelligence and experience would break it up without being told. He rejected the allegation that a warning should have been given of the risk of contracting PDA4. It was not the practice in the industry to give such a warning. This could be counterproductive, because it might precipitate the condition which it was intended to avoid.

      It will be clear from this summary that the issues which the judge had to decide were all issues of fact. The answers which he gave to them were the result of his assessment of all the evidence, after seeing and hearing all the witnesses. He had to resolve an acute conflict in the expert medical evidence. Another disputed question which he had to resolve was what to make of the respondent's evidence. This was important because of the account which she gave as to the development of her condition and as to the nature and amount of her typing work. His impression of her was that she was a dutiful, conscientious and responsible person, and it had not been suggested that she was malingering. But he thought that in her evidence she was at times prone to exaggeration and some inconsistency, although she was not trying to deliberately mislead the court. In this situation he had to examine her evidence on these matters very carefully. He had to test it against the evidence of the other witnesses whose evidence seemed to him to be reliable.

      The respondent appealed against the order made by the trial judge. The Court of Appeal allowed her appeal, but this was a decision by a majority. Stuart-Smith L.J. and Waite L.J. were satisfied that there were sufficient deficiencies in the judgment to justify their intervention on the facts. Having examined the evidence, they reversed his findings on causation, foreseeability and negligence. Swinton Thomas L.J. dissented. He said that he did not believe that it was open to the court to reverse the various findings of fact made by the judge who had had the advantage of seeing and hearing the witnesses.

      I have come to the view, with the greatest of respect to the very experienced judges who constituted the majority, that the Court of Appeal ought not to have disturbed the findings which were made by the trial judge. I am unable to accept the criticisms which were made of his judgment by the majority. It seems to me that he came to a decision on all the main issues which he was fully entitled to reach on the evidence. I have also found it hard to reconcile some of the criticisms of the judgment which were made by the majority with the state of the evidence. This has tended to strengthen my view that the trial judge reached a decision which he was entitled to reach and that it ought not to have been reversed on appeal.

      It will be necessary for me to examine in some detail the reasons which the majority gave for reversing the trial judge. It was to these reasons that Mr. Hytner Q.C. directed the main part of his argument. He said that the Court of Appeal had been wrong to reverse the trial judge both as to where the burden of proof lay in this case and also on various primary findings of fact by the trial judge which went to the root of the issues of causation, foreseeability and negligence. Mr. Redfern Q.C., in seeking to support the decision of the majority, maintained that the decision by the trial judge was vitiated by errors which he had made, especially with regard to the medical evidence. I shall deal with these arguments stage by stage as I examine the state of the evidence.

The Medical Issues

      The judge described the three issues which fall under this heading in this way: firstly, whether PDA4, cramp of the hand due to repetitive movements, has an organic cause; secondly, whether the respondent has had PDA4; and thirdly, if she has had it, whether her PDA4 has an organic cause. I have placed them all under the heading of medical issues. But it is clear from his judgment that the judge was unable to resolve all of them without taking account of a substantial body of evidence from the lay witnesses about the work which the respondent was doing during the critical period.

      As to the first issue, the judge said that the most that he could find on the whole of the medical evidence was that the condition of cramp of the hand due to repetitive movements may have an organic cause or a psychogenic cause or a combination of both causes, and that this was a matter for the court to consider on the evidence before it in each case. In the Court of Appeal Stuart-Smith L.J. described this conclusion as entirely unexceptional. But he then went on to make some comments about the state of the controversy which reveal that his approach to it was very different from the position of neutrality which the judge had decided to adopt at this stage in his examination of the evidence.

      The judge's conclusion was, as Stuart-Smith L.J. noted, in accordance with the evidence of the respondent's witnesses Mr. Stanley, an orthopaedic surgeon, and Dr. Hay, a psychiatrist. The appellants' witness Dr. Lucire, who was also a psychiatrist, said in her evidence that she had found that, where an organic cause was present, it was not related to repetitive movements but to some other organic disorder such as gout. Her explanation for the condition was that in her experience it was due invariably to a somatisation syndrome. Stuart-Smith L.J. said that her evidence was that all cases of PDA4 are due to conversion hysteria. But that was to oversimplify the effect of her evidence. It is true that her diagnosis was that, in the respondent's case, the cramp was the product of conversion hysteria--that is to say, that her mind was using her body to escape from a situation at her work which she had found to be objectionable. But her evidence, when speaking about the condition generally, was not so confined. She talked in quite general terms about somatisation and the phenomenon of hysteria. She said that one had to be careful in ascribing either an organic cause or a psychogenic cause. In this respect she agreed with Dr. Hay, although there was an important difference between them as to the proper starting point. Dr. Hay's position was that a diagnosis that there was a psychogenic cause had to be made with great caution, and then only when there was an absence of a physical cause. He said that conversion hysteria was a rare condition and that it was a diagnosis which had frequently been shown to be wrong. But Dr. Lucire's experience was to the contrary.

      As to the state of the controversy, Mr. Stanley was a strong supporter of the organic school. Yet he accepted that it was an impossible task for a judge to decide which school was right and which school was wrong. In the light of his evidence there can be no doubt that the trial judge was right not to attempt to resolve this dispute. He was right also to describe the possible causes on either side in quite general terms within which a range of diagnoses might be acceptable. But it seems to me that Stuart-Smith L.J. was unwilling to accept that the question as to which school was right was still an open one. Having, as I think, over-simplified the effect of Dr. Lucire's evidence, he said that with advances in medical knowledge and improved medical technology the psychogenic approach had to a large extent been discredited. That however was not the judge's view of the medical evidence which was before him in this case. Whatever may have been the case where other conditions have been said wrongly to have had a psychogenic origin, the evidence in this case was that the pathology for PDA4 is uncertain as it has yet to be demonstrated. I do not think that general knowledge about improvements in medical science and technology, which were not the subject of any evidence, provided a sufficient basis for differing from the judge's view that a neutral position had to be adopted in this case as to the present state of the controversy.

      This difference of view between the majority in the Court of Appeal and the judge on this initial question has an important bearing on the way in which, from different starting points, they approached the other issues in the light of the medical evidence. I do not think that I am being unfair to the majority when I say that it seems to me that they were, from the outset, sceptical about the suggestion that the condition was anything other than organic in origin. The judge, on the other hand, was much more circumspect. As to the second issue, he was careful to say that, while he was disposed to find that the respondent had a cramp of the hand, he was not satisfied that it was due to the repetitive movements of typing in the sense that such movements were an effective cause of it. His choice of words was important, because PDA4 has been defined as "cramp of the hand due to repetitive movements." To accept without qualification that her cramp was PDA4 might be taken as resolving the next issue, as to whether there was an organic cause in this case. That, the most controversial medical issue in the case, the judge wished to examine separately. The majority in the Court of Appeal said that the judge had concluded, without saying so, that the respondent had PDA4. They omitted to add the qualification which the judge had made. By implication they were criticising his finding as lacking in clarity. I think that they were wrong to do so, as the judge made it clear that the question whether this was cramp due to repetitive movements was one which, at this stage, was still unresolved. Their difference of view from the judge on this point provides the explanation for the further and more fundamental difference between them about the proper approach to be taken to the third issue.

      The judge said, in regard to the third issue as to the cause of the cramp, that the appellants did not have to satisfy him that the cause was psychogenic: the onus was on the respondent to establish that the cause was organic. Stuart-Smith L.J. said, at [1997] I.C.R 566,574, that this was a misdirection:

 "Having established that she had PDA4 there were two alternative explanations for it advanced by the medical experts one-supported by the evidence of Mr. Stanley and Dr. Hay- was that it was organic; the other-supported by Dr. Lucire-that it was psychogenic being a conversion hysteria. No other hysterical or psychogenic explanation was advanced. It seems to me that what the judge had to do was simply to decide upon the evidence which of these two explanations was the most likely. In the result the judge said that he was not satisfied that it was organic: therefore by inference it must be psychogenic; but he did not accept Dr. Lucire's explanation that it was conversion hysteria."

Waite L.J., at p. 593 was equally critical of the approach which the judge took as to where the onus lay on this issue:

 "That represents, to my mind, a plain misdirection in law. Why should a plaintiff who has established a condition of PDA4, and who has satisfied the court that the only psychogenic condition relied on against her does not apply in her case, be under any duty to prove a negative and demonstrate that her complaint had no psychiatric origin? Given the intricacies of the human mind, and the breadth of emotional range to which everyone is subject from mere stress at one extreme to hysteria at the other, it seems to me to be illogical, as well as unjust, to lay upon an individual complaining of industrial injury the burden, in the absence of any specific psychiatric diagnosis established by his opponent, of proving a non-psychogenic origin for physical symptoms that are accepted to be genuine."

In my opinion the judge was right to insist that it was for the respondent to satisfy him that her cramp had an organic cause. This was the basis of her case that her condition was foreseeable and that, in failing to take precautions against it, the appellants had been negligent. Unless an organic cause for it was established, her claim for damages was without any foundation in the evidence.

      There is no doubt that in most cases the question of onus ceases to be of any importance once all the evidence is out and before the court. But in this case it was not so simple. As Lord Thankerton observed in Watt v. Thomas [1947] A.C. 484, 487 the question of burden of proof as a determining factor does not arise at the end of the case except in so far as the court is ultimately unable to come to a definite conclusion on the evidence, or some part of it, and the question arises as to which party has to suffer from this. From time to time cases arise which are of that exceptional character. They include cases which depend on the assessment of complex and disputed medical evidence, where the court finds itself in difficulty in reaching a decision as to which side of the argument is the more acceptable. I think that this was such a case, and that the judge was justified in reminding himself where the onus lay as he examined the evidence.

      There were two competing explanations for the condition which had been advanced by the medical experts. Neither of them was wholly satisfactory. Mr. Stanley's explanation that the cramp had an organic cause was open to some criticism. He did not see the respondent until more than three years after May 1989, so he could not say whether the symptoms which formed part of his diagnosis were present on that date. He said that he found three manifestations of functional distonia when he saw her in 1993: a significant weakness of grip, poor function of the hands and loss of muscle bulk. But her grip was tested by Mr. Holt, a rheumatologist recommended by the Repetitive Strain Injury Association, in October 1989. He reported that she had a very good grip, and that he was rather doubtful whether her condition was repetitive strain injury. Dr. Williams, another rheumatologist, examined her in October 1992. He found that her grip was scale four on a scale of five, and that this was normal for a person of her build. The judge said that he found the results of these tests difficult to reconcile with the test which Mr. Stanley had carried out, and he noted Mr. Stanley's acceptance that disuse atrophy is common where the hand is not used. He also noted that none of the doctors who had seen the respondent in 1989 and 1990 had seen any spasm or tremor which, although they are not always present, are two of the symptoms of PDA4 described in the guidance notes. As for Dr. Lucire's diagnosis of conversion hysteria, the judge noted that this explanation also was a difficult one to accept in the light of Dr. Hay's evidence.

      The position which the judge reached after reviewing the medical evidence was that he was unable to decide on that evidence alone whether the organic explanation was the more probable. That was why, after saying what he did about onus, he proceeded to examine the other evidence in order to see whether the onus had been satisfied. This included the respondent's evidence, some of which he thought was exaggerated, and the evidence of two ergonomists. They were agreed that repetitive movements were unlikely to cause injury unless accompanied by other factors, none of which were found by the judge to have been present in this case. He also took into account the findings which he had made about the speed, duration and amount of the respondent's typing work after testing her evidence against that of other witnesses for whom she worked during the critical period. It was only after completing this review and making his findings in the light of all this other evidence that he reached his decision that the respondent had failed to satisfy him that her cramp had been caused by the typing work.

      The majority in the Court of Appeal appear to have thought that the whole matter ought to have been disposed of by looking solely at the medical evidence. On their approach it was enough that the judge was unwilling to accept Dr. Lucire's explanation that the respondent's condition was conversion hysteria. That being so, as there was no other explanation, the conclusion was in their view inevitable that this was a condition which was organic in origin. I have already observed that in my opinion they were approaching the matter from the wrong starting point. But their disposal of this issue is open to objection on more fundamental grounds.

      In the first place what they were doing was to invert the onus of proof. The respondent's whole case was that her cramp had an organic cause. It was essential to her success that it was proved to have been caused by repetitive movements while typing. So, according to the ordinary rule, the onus was on her to prove that the cause which she had alleged was the right one. It was open to the appellants to lead evidence in rebuttal to the effect that its cause was a psychogenic one. But they did not have to prove that it was due to a conversion hysteria. Failure to prove this alternative explanation was a factor to be taken into account in the decision as to whether the respondent had established an organic cause, but it was no more than that. It still left open the question, in the light of the wider dispute revealed by the medical evidence, whether an organic cause had been established for the cramp so that it could be said to have been due to the respondent's typing work. It was precisely because he was unable to answer this question in her favour on the medical evidence that the judge turned for such assistance as it might offer to the other evidence.

      In the second place, the judge had the advantage of seeing and hearing all the medical evidence. The majority of the Court of Appeal said that they were well aware of the rules which define the approach which an appellate court should adopt in these circumstances. But they did not apply them as they should have done in the circumstances. As Lord Bridge of Harwich said in Wilsher v. Essex Area Health Authority [1988] AC 1074, 1091, the advantage which the trial judge enjoys is not confined to conflicts of primary fact on purely mundane matters between lay witnesses. In this case the medical experts were at odds with each other about complex issues which were particularly difficult to resolve as no pathology for the condition known as PDA4 has yet been demonstrated. They were examined and cross examined on these issues over several days. Their demeanour and the manner which they gave their evidence was before the judge, who saw and heard them while they were in the witness box. All the Court of Appeal had before them was the printed evidence. The view of the judge that he was unable to come to a conclusion about the effect of this evidence without taking into account the evidence of the lay witnesses was entitled to much greater weight than the majority were willing to give to it. For my part, I think that his approach to this matter was entirely justified in the light of the difficult issues which were presented to him by the medical evidence. In the light of the evidence about the nature and duration of the respondent's typing work, I regard the view of the majority that the judge had no alternative but to accept that there was an organic cause for the cramp as a wholly mistaken one. I think that it was due to an incomplete understanding of the effect of the evidence.

      There is one other criticism of the judge's findings with which I must deal before I leave the issues covered by the medical evidence. It relates to the judge's treatment of the respondent's entry in her diary for 23 May 1989. This was the first entry in the diary, which she had been keeping since 1987, in which she mentioned any trouble in her hands. She recorded in this entry that it had started late in the previous year when she noticed by Friday that her hands were tight and sore, and that she had been typing flat out all that summer to keep up with her typing work. The judge said that he had difficulty in accepting her explanation for not mentioning the problem in earlier entries at the time when the pain was afflicting her and for doing so on 23 May 1989 retrospectively. In expressing this view he said that he had regard also to the opportunities which she had had to mention her trouble on other occasions at or about that time. These included occasions when she could have mentioned it both to her G.P. and to Mr. Mason, one of the managers, when she was discussing her work appraisal with him. He had already noted in his judgment that she was at time prone to exaggerate during her evidence and to some inconsistency, although not to the extent of deliberately misleading the court.

      The majority in the Court of Appeal were particularly critical of his assessment of her evidence. They said that his reasons for not accepting her diary entry made no sense. He could only have meant that she had lied about this entry, which was quite inconsistent with his finding that she had not deliberately misled the court. They made much of this point, as it was their view that the judge had not taken proper advantage of the fact that he had seen and heard her while she was giving her evidence. Having rejected his treatment of her evidence, they went on to rely upon her evidence without subjecting it to the same critical analysis as the judge had given to it. But I think that they made too much of the point, and that they misunderstood the nature of the difficulty. There was no reason to think that the diary entry was a lie. There was no suggestion that she had made up the entry deliberately in order to mislead the court. She had made it in her own private diary, to record her own thoughts at the time when she was writing it. The point which concerned the judge was not whether it was a dishonest entry-- was it really to be thought that she would lie to herself? -but rather whether, as an accurate record of the history of her condition, it was reliable. I think that the judge was fully entitled to express his concern on this point, and to insist that before he accepted the entry as a reliable one it should be tested against the rest of the evidence. On this matter also the majority ought to have acknowledged that the judge had the advantage over them of hearing the respondent's explanation while she was giving her evidence. As Swinton Thomas L.J. said in his dissenting judgment, the judge was entitled to come to the conclusion that he did on this issue of fact, and it was quite impossible for a Court of Appeal to substitute its own finding of fact on it.

Causation

      The fourth issue which was identified by the judge was whether the respondent's PDA4 was caused by her work as opposed to being work related. Although she had failed to satisfy him that her cramp had an organic cause, it was still necessary for him to examine this issue in order to decide whether the disease might nevertheless have been caused by the prolonged typing work which the respondent said she had to do while employed by the appellants as a secretary.
 

      The majority in the Court of Appeal had no difficulty with this issue. Stuart-Smith L.J. said that once it was concluded, as in his view it had to be, that her condition was an organic one, this cast a flood of light upon and in support of her evidence that she was working--that is to say, typing--during the critical periods for prolonged stretches and for about 75 per cent. of her working day. This however was the evidence of a witness whom the trial judge, who had had the opportunity of observing her in the witness box, described as at time prone to exaggeration and some inconsistency. One of her complaints had been that the pressure of work had been such that during most days she had to type not only for long hours but also at high speed. Her normal typing speed was 60 words per minute, but she estimated that she was getting up to 80 words per minute on her word processor. The judge heard evidence from other witnesses to the effect that a typist could not exceed her natural optimum speed of about 60 words per minute on the word processor for any sustained period, but only exceptionally and briefly to type the odd letter or document. Stuart-Smith L.J. said that the judge was entitled to find that the respondent had exaggerated in this respect, but that in his view that did not affect the position as on any showing all the evidence showed that she was a fast typist and it was prolonged unbroken spells of typing that were the trouble. Speed however was not the only matter about which the judge held that the respondent was prone to exaggerate. This assessment of the reliability of her evidence applied also to the question whether she was typing for prolonged periods--a very loose expression, which in this case meant very little unless it was related to the opportunities which arose naturally during the course of that work for breaks and other rest periods.

      What the judge found on this issue was that at the relevant times in 1988 and 1989 the respondent did not as a general rule spend more than three and three quarter hours per day--50 per cent. of her working time--on typing. He accepted that from time to time during these periods, in order to type an urgent letter or document, she might have typed for up to five hours per day--75 per cent. of her working time, leaving aside her half an hour lunch period. But he also found that during these periods she had ample scope to intersperse her typing with the remaining two and a half hours of non-typing secretarial work. While there were peaks and troughs, and while the peaks may have seemed excessive in the respondent's perception, she had the necessary discretion, knowledge and experience to plan, organise, prioritise and negotiate the work and, if necessary, to seek help to enable herself to cope reasonably with it. As there was no evidence to show that she was not coping with her other non-secretarial work, the implication was that the periods of typing were not being undertaken for prolonged periods without interruption as she had claimed. The majority in the Court of Appeal were critical of these findings. But much of their discussion of this issue seems to have been influenced by the view which they had already formed that her condition was organic and that, as it was only in circumstances of excessive typing that this condition would develop, her account of what she was doing was supported by the nature of her condition as being accurate. They were also of the view that the difference between the respondent's account of her work and what the judge was prepared to accept about this was so great that he must have been saying that she was being dishonest about it--something which in his assessment of her evidence he had expressly negatived. There were some other details which they used to support their view that the judge ought to have accepted the respondent's account of the time which she had had to spend on her typing work. For example, Stuart-Smith L.J. said that she had said that her job was done by two people after she ceased her employment with ICI.

      The judge had however heard a good deal of evidence on this issue. Some of this evidence gave some limited support to the respondent's contention that she was from to time being overworked. But there was also much evidence, other than her own assessment, to show that she was not working without any interruption for prolonged periods on typing work. On the only occasion when she was asked to put a figure on this, the respondent said that the time which she spent on typing during the critical periods amounted to "possibly around 75 per cent." of her working time. Strictly speaking, after allowing for her lunch break, the judge's finding that this could be expressed as five hours of her working time was a slight underestimate. But the important point which emerged clearly from the evidence of the other witnesses was that throughout her working time, despite several complaints in her diary of overworking, the respondent was able to satisfy all the other demands which were made on her in the performance of her other duties as the secretary to three section managers. There were no complaints by those for whom she was working of poor service or of inefficiency. The nature of those other duties was such that she had to attend to them, as and when they arose, throughout her working day. They provided frequent natural breaks from typing as she answered the telephone, left her desk to speak to the managers elsewhere when they were not contactable by telephone, arranged meetings for them, made diary entries and so on. Her own job description, which she had prepared to show the work she was doing in 1986 to provide a secretarial service in her department, impressed the judge because of the range and variety of her work. As for the suggestion that her job was done by two people when she left her employment, the evidence showed that nothing much could be made of this. The respondent accepted that there was some readjustment of her work after she left ICI. One of the managers, Mr. Mason, took on his own secretary and there was an increase in the work which had to be done for the other managers.

      Taking the evidence as a whole, the judge was far better placed than the Court of Appeal was to assess to what extent, if at all, the respondent was exaggerating and which of the other witnesses who tended to contradict her were the more reliable. Here indeed were primary findings of fact on mundane matters, to adopt Lord Bridge's description in Wilsher v. Essex Area Health Authority [1988] AC 1074, with which the Court of Appeal were not entitled to interfere. As for the comment that the organic nature of the respondent's cramp cast a flood of light on her claim that she was typing for prolonged periods, this proposition may equally well be run round the other way. It may indeed be said that the judge's conclusions about the amount and nature of the respondent's typing work, based on his assessment of the reliability of the evidence given by the various witnesses, cast a great deal of light upon the question whether her condition had been proved to have been an organic one.

Foreseeability and Negligence

      The judge held that it was not reasonably foreseeable, in the state of knowledge about the condition in 1988 and 1989, that the work which the respondent was required to do as a secretary would be likely to cause her to contract PDA4. As he put it, while it was technically foreseeable that a typist might suffer from this condition, it was not reasonably foreseeable that this would happen to a secretary who was typing to the extent which he found established by the evidence. He also held that the respondent had not established the grounds on which she had claimed that the appellants were negligent.

      In her particulars of negligence the respondent had alleged that the appellants were negligent because they had failed to warn her of the risk of developing the condition from typing at a fast speed all day without respite apart from her lunch break. At the trial the allegation was that they had failed to take steps to ensure that she was given the same instruction, warnings and advice as were given to the typists in the accounts department. The judge did not think that the appellants were under a duty to prescribe for the respondent rest periods from her typing work, as she had ample non-typing secretarial work to intersperse with it. He said that her work lent itself naturally to rotation and interspersment. He pointed out that the respondent herself had rejected the notion that a regime might be imposed upon her which, as a secretary and not a typist, she would have regarded as unsuitable. This was, he said, a matter of common sense. He rejected the allegation that a warning should have been given to her, on the grounds that the condition was uncommon and, on the evidence, very rare in the case of typists, that it was not the practice in the industry to give such a warning and that to do this, in the case of such a vague condition which was not easily identifiable, might well be counterproductive.

      The majority in the Court of Appeal held that it was plainly reasonably foreseeable that typists might suffer from the condition if they typed for long periods without break, and that the appellants should have given the same advice, instructions and warning as they gave to the typists in the accounts department. It is clear from their reasoning that they were proceeding on the basis that the amount and nature of the respondent's typing work was not materially different from that done by the typists in that department. As in their case, as they understood it, she also was required to type for long periods without breaks or rest pauses. So she needed to be given the same advice and instructions as had been given to them so that she would take breaks and rest periods, and she should have been given a warning in order to ensure that she did what she was told. Without that warning she would not have had the requisite knowledge that it was necessary for her for her own health to take breaks from prolonged spells of typing work.

      There are two flaws in this approach which in my opinion wholly undermine the conclusion by the majority that in this case the appellants were negligent. The first is their assumption that the respondent's evidence that she was typing for prolonged periods with breaks and rest pauses was accurate and reliable. The second is their failure to appreciate, and to take into account, the fact that the nature and variety of her other work lent itself naturally to rotation and interspersment with her typing work. This was not something that had to be laid down in advance. The breaks and rest pauses from typing, on the judge's findings, occurred naturally throughout her working day because of the variety of the duties which she had to perform as a secretary.

      In effect, the majority rejected the judge's assessment that the respondent's evidence was affected from time to time by exaggeration and inconsistency and that it had to be tested carefully against the other evidence. They left out of account his detailed analysis of the evidence of the other witnesses whom he accepted as reliable. Had they accepted that analysis, they would have seen that her position was quite different from that of the typists in the accounts department. The typists who worked there had no other work to do other than typing. In their case steps had to be taken by way of forward planning to ensure that they took breaks and rest pauses. In her case this was not so. Even when she was spending up to 75 per cent. of her time on typing work she still had 25 per cent. of her time, in addition to her lunch break, to do her other work which was spread naturally over her working day. Unlike the typists, she had both the experience and responsibility to organise and plan her own work according to its requirements from day to day. She did not need to be told what to do.

      There was also a good deal of evidence to show that the appellants had taken steps to enquire into, and to provide against, the possibility that the operators of word processors might suffer from fatigue--in itself not harmful to health--and possible injury due to poor posture and other undesirable working practices. At a meeting held in Runcorn in May 1987 five possible health concerns had been identified by them. These were back-ache, eyestrain/headache, effective lighting, radiation/pregnancy and repetitive strain injury. In the case of repetitive strain injury it was noted that this complaint was most often associated with a combination of poor hand position and typing too fast. It was not suggested that the respondent had been adopting a poor hand position, and her complaint of typing too fast was rejected by the judge on the evidence. It was noted that the results of repetitive strain injury were pain, swelling and discomfort in the fingers and wrist. The respondent's complaint when she went to see the works doctor, Dr. Lamb, on 31 May 1989 was of pain in the back of her hands. He said that he was unable to find any physical sign of the pain, and that he had not seen or heard of similar symptoms.

      As for the giving of warnings, the respondent said in her particulars of negligence that she should have been told of the risk of contracting PDA4. The giving of warnings of the risk of disease or injury is a precaution which is familiar in the field of litigation for personal injury. But in the case of conditions such as PDA4, which are not easily identifiable and not well understood, great caution must be exercised as to the content of any such warning and as to whether to give a warning at all is appropriate. To impose a duty which may cause more harm than good would be undesirable. The law does not compel employers to take steps which may bring about the condition which they wish to prevent. Conditions which are associated with functional or psychogenic disorders present particular difficulty. So the judge was right to pay careful attention to the advice of the experts, and to the practice in the industry, as to precise terms of any warning that the appellants might responsibly give to their employees about the risk of contracting PDA4.

      Dr. Hay said that those who were prone to anxiety might perceive that they had the symptoms of the disease, so a balance had to be struck. On the other hand a balanced warning might simply do no more than accord with the common sense precautions which everyone would take. Mr. Stanley said that it would be disgraceful to give a warning which said that if you developed pain you may never work again. The warning which he would have regarded as acceptable was simply to go and see the works doctor if you develop unusual pain or discomfort. But that was not the kind of warning which the respondent was looking for--she went her GP two days after she had noted in her diary for the first time that she had pain in her hands, and a few days later she was seen by the works doctor. The judge accepted the evidence of Mr. Pearce, the appellant's ergonomist, that it was not the practice in industry in 1988 and 1989 to give a warning of any kind about the risk of contracting PDA4, and that of Dr. Teasdale, the appellants' chief medical officer, who said that no literature had ever come to his attention advocating such a warning. His evidence was that the appellants were well aware that poor siting of equipment could lead to eye strain and other disorders, and that steps had been taken to ensure suitable work station design and siting and that appropriate information was given to visual display operatives. But he would have regarded a warning that muscle fatigue might develop into PDA4, a rare disease, to be counterproductive and, in the absence of advice by a suitable expert body such as the Health and Safety Executive to the contrary, he did not consider it necessary or proper to give such warnings. The judge also accepted Dr. Lamb's evidence that a formal system of instruction, warning and advice was adopted and implemented for typing staff in the accounts department as the working day was confined to accounts and difficulties in changing postures could arise in their case. But such a system was not considered necessary for secretaries as they carried out many non-typing duties in the course of their working day.

      Stuart-Smith L.J. said that he was not moved by the suggestion that the giving of warnings might give rise to difficulty. In his opinion all employers had to do was to give the instructions, advice and warning which the appellants gave to those they considered to be at risk of doing excessive typing. It seems that the kind of warning which he had in mind was that described by Dr. Lamb, which is not what the respondent was asking for. But the judge had ample evidence before him to justify the decision which he took that in the respondent's case this was unnecessary. I think that he was right to regard her case as entirely different from that of the typists in the accounts department. She was not required, as they were, to work continuously on a word processor, and the appellants had no reason to anticipate that she was exposed to the same risk of contracting PDA4 which, in any event, was minimal in their case.

      The decisive point which emerges from this part of the case is that the respondent's claim that her typing work was comparable with that done by the typists in the accounts department was shown, by a careful analysis of the evidence, to be exaggerated and unsupportable. The findings by the judge that the condition was not reasonably foreseeable in her case and that the appellants were not negligent in the respects alleged by her were, in my opinion, soundly based on the evidence. I do not think that the Court of Appeal should have interfered with his decision that the appellants were not liable to the respondent in damages. I would allow this appeal.