Cases Concerning repetitive strain injury engender fierce disputes, as doctor is pitched against doctor.

They are, however, focused on just two main issues; that of terminology - what to call the range of upper limb disorders complained of - and that of causation - the extent to which repetitive work may cause certain upper limb conditions.The controversy surrounding terminology is much overplayed and, as evidenced following the case of Mughal v Reuters in October 1993 ([1993] IRLR 571), where His Honour Judge Prosser described the term RSI as 'meaningless', much over quoted.There are a whole variety of labels attached to these strain conditions.

Repetitive strain injury, occupational overuse syndrome and work-related upper limb disorder, to name but three.

Insurance companies, their doctors and solicitors dislike the insinuation of work and injury related to these terms.The name used does not matter.

It has become a semantic distraction overplayed by defendants.

The more fundamental issue is that of diagnosis of upper limb disorders and their connection with work.All the upper limb conditions that can be work-related may also be constitutional in origin.

Defendants argue a constitutional cause for conditions such as tenosynovitis and De Quervains syndrome.

Plaintiffs point to repetitive work carried out by the sufferer.I represented the plaintiffs in the case of Mountenay v Bernard Matthews plc (unreported), in which judgment was given in favour of six of out nine plaintiffs in July 1993 at Norwich County Court.

The defendants were represented by Clive Brynley-Jones, who wrote an article on the subject of RSI in general, and the Bernard Matthews case in particular, in [1994] Gazette, 11 May, 23.In this case, as in many others, much depended upon evidence of the system of work operated by the employers.

It would be very difficult for a judge, faced with evidence of repetitive work, few breaks and inadequate rotation, to find, on the balance of probabilities, that working practices were not to blame.

The inevitability of this conclusion was effectively conceded in the Bernard Matthews cases by one of the defendants' doctors.The most recent RSI decision (accompanied by the customary media interest) was that of Adele Smith v Baker McKenzie, heard before His Honour Judge Callman in the Mayor's and City of London Court.

Judgment was given in the plaintiff's favour on 11 April 1994 (see [1994] Gazette, 13 April, 5).Ms Smith, who worked as a typist for the defendant firm, claimed the development of a left-sided tenosynovitis followed three days spent typing up minutes of the firm's Rome partners' meeting with few breaks and no rotation.

Baker McKenzie made an admission in the course of trial that the typing of the minutes of the partners' meeting gave rise to a foreseeable risk that the plaintiff would develop an upper limb disorder.

The issue to be decided by the trial judge was one of causation.His Honour Judge Callman preferred the evidence of the plaintiff's medical expert, who said arduous typing had caused the tenosynovitis, to that of the defendants' expert, Mr Campbell-Semple, who claimed the condition was either constitutional or secondary to a ganglion.While employers may be losing RSI cases, the value and number of litigated cases remain relatively low.

For the future, defendants fear judgments in favour of sufferers from diffuse RSI.

They also fear that the concept of sensitiza tion may be accepted by the courts.So called diffuse conditions are considered to be those where a plaintiff who has carried out repetitive work feels upper limb pain but has no physical manifestations, such as swelling, to evidence the injury.In his article, Mr Brynley-Jones correctly reported that the trial judge in Bernard Matthews found only a limited form of diffuse condition to have been proven to exist in the plaintiffs before him.

There was only one Bernard Matthews plaintiff who specifically complained of diffuse RSI.His Honour Judge Mellor considered four possible explanations for the complaints and concluded: 'There are those whose susceptibility to pain is such that that which is transmitted along their nerves is indeed greater pain than most might be expected to experience under like stimulation.

That is to say that just as there are those who develop a pathological condition when others would not, there are those whose experience of pain under a particular stimulus is very much greater than the norm.'He also commented: 'I regard it as likely that abnormal pain has at times been consequent upon the work they have performed rather than upon some misconception as to the effects upon them of their employment.

I should perhaps add that in reaching this conclusion I have proceeded on the basis that pain itself, whether one chooses to define it as a physical or as a mental entity, is harm.

The vital question in the individual cases must be as to whether such pain is propter and not merely post or concurrent to a material breach of duty by the defendant.'Judgment was given in favour of the plaintiff suffering from diffuse RSI.

It was in the light of that finding and the complete decision of His Honour Judge Mellor that the Transport & General Workers Union (TGWU), which brought the cases, quite properly claimed that diffuse RSI was for the first time recognised by the courts.Some sufferers from repetitive strain injuries claim that the pain suffered by them continues beyond the time of their carrying out the repetitive work.

They claim that the work has sensitized them to future repetitive work and causes continued limited dexterity in their hands.

This has significant consequences for the value of RSI claims, particularly future loss.Acceptance of the concept of sensitization is, like the notion of diffuse RSI, likely to be fought tooth and nail by defendants.In Bernard Matthews, sums were claimed from the defendants by way of special damages and future loss to reflect the plaintiffs' claims of continued sensitivity, their inability to work and reliance upon others.

His Honour Judge Mellor did not find that the issue of sensitization had been proved by the plaintiffs in Bernard Matthews and damages were limited accordingly.In the more recent case of Smith, His Honour Judge Callman accepted that the plaintiff continued to experience pain as a result of the development of tenosynovitis.

In that case special damages, loss of earnings to the date of trial (and into the future) as well as a Smith v Manchester award totalled £25,172.

The general damage award was of £7250.Every case is decided upon its own facts.

Diffuse cases will no doubt remain controversial and the acceptance of sensitization will be opposed all the way but, call it what you like, 'kangaroo paw' is here to stay.