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published work. This situation demands a dedicated individual with sophisticated skills. There are many who qualified on courses which did not provide the tools necessary for the comprehension and interpretation of research material. However, the acquisition of such skills is necessary for the clinician of today and must not be seen as irrelevant, but this is not to underestimate the theoretical and practical issues involved. A number of surveys have shown a poor readership for the research published even in professional journals such as this, let alone the more specialised ones. This is a sad reflection on our professional status.

I believe that our continued professional development hinges upon a genuine acceptance of the value and the necessity of people who are clinicians, researchers and a mixture of both in a variety of environments. Lip service alone is not enough. This acceptance must be reflected in the career structure and the close collaboration of all categories of professionals. It is to be hoped tha t the NHS R&D priority setting exercise will act as both a focus and trigger for this to take place.

Di Newham PhD MCSP Professor of Physiotherapy, King’s College London

FORUM

Randomised Controlled Trials and Single-instance Experiments Ian Robertson

There have been several articles on single case experimental design in recent issues of Physiotherapy. While I share the methodological reservations of Chris Bithell (February, pages 85-87) about many types of single case experimental design, I think she is fundamentally wrong in her implicit conclusion that such designs are not suitable for use in physiotherapy research.

On the contrary, single case experimental designs are not only useful, they are essential if a properly scienti- fically based rehabilitation is to be developed.

I have myself published both randomised group studies (see for instance, Robertson et al, 1990) and also single case experimental designs (see for instance, Robertson et al, 1992). A randomised controlled trial which produces negative results is an extremely expensive way of answering a single question. Randomised controlled trials in rehabilitation research are in most cases premature for the time being, as for the most part almost everything that is done in rehabilitation is completely unevaluated and scientifically poorly based. For that reason, there is a very pressing need slowly to accumulate carefully controlled single case experimental designs of theoretically based rehabilitation strategies, gradually working up to large multicentre randomised controlled trials. Without the former, the latter are really unlikely either to be successful or to be funded.

Another problem with randomised controlled trials is that whether one gets a positive or a negative answer, it is not clear precisely why the therapeutic effects have occurred, particularly in randomised controlled trials where the therapeutic strategy has a clinical rationale rather than a theoretical one.

If I may again draw on my own research to give one example of the value of single case experimental designs in rehabilitation research, I have recently shown how a uni-lateral limb activation in hemiplegia where uni- lateral left neglect is present can produce significant improvements in uni-lateral neglect (Robertson et a1 1992). Through careful single case experimental studies

of the nature of this limb activation phenomenon, I furthermore discovered that the advantages acruing to uni-lateral activation of the hemiplegic limb were not achieved with passive activation of that limb (Robertson et al, 1993). Furthermore, i n a subsequent study, it emerged that the benefit effects of uni-lateral activation were abolished by bi-manual activation of both limbs simultaneously (Robertson and North, 1994). This finding has major implications, for instance, for Bobath approaches to hemiplegic patients with uni-lateral neglect, as i t suggests that the bi-manual approach may actually hinder therapeutic gains which would accrue to uni-lateral activation.

Had I focused my research on randomised group trials, then such findings would never have emerged, and I think this is a n example of the importance, and indeed necessity, of carefully controlled single case experimental designs as a precursor to carefully controlled randomised group designs. In my opinion, for many techniques and many approaches to rehabilitation, the randomised group trial is many years away, and researchers i n physiotherapy and other rehabilitation fields are by necessity compelled to become expert in, and familiar with, single case experimental designs.

References Robertson, I H, Grey, J, Pentland, B and Waite, L (1990). ‘A randomised controlled trial of computerised cognitive rehabilitation’ for uni-lateral left neglect’, Archives of Physical Medicine and Rehabilitation, 71, 663 - 668.

Robertson, I H, North, N , and Geggie, C (1992). ‘Spatio-motor cueing in unilateral neglect: Three single case studies of its therapeutic effectiveness’, Journal of Neurology, Neurosurgery and Psychiatry, 55, 799 - 805. Robertson, I H, and North, N (1993). ‘Spatio-motor cueing in uni- lateral neglect: The role of hemispace, hand and motor activation’, Neuropsychologia, 31, 293 - 300. Robertson, I H, and North, N (1994). ‘One hand is better than two: Motor extinction of left hand advantage in uni-lateral neglect’, Neuropsychologia, 32, 121.

Author and Address for Correspondence Ian Robertson PhD is a senior scientist in the Medical Research Council, Applied Psychology Unit, 15 Chaucer Road, Cambridge CB2 3EF.

Physiotherapy, June 1994, vol80, no 6