components may be required, it isjust that at present the weight ofevidence favours a shift towardsdealing with disability, function,beliefs, fears, distress andbehaviours rather than over-focusedhype on minor physicalimpairments and treatmentsdominated by passive inputs. Pain is never ignored.

� I believe that UK physiotherapistsare leading the world in amovement which with enoughsupport will deliver reduceddisability levels and better, healthierlives to a great many. Nothing thetreatment-brandishing gurus havecome up with yet has offeredsignificant evidence of such hope aswe now have. There is a great dealof talent in the UK, let us be proudof it and of those quiet unobtrusive

therapists whose philosophies areprofound, yet whose presence goesunnoticed in a profession wherefame and recognition are too oftenattached to charisma andquestionable reasoning.

Louis GiffordMCSPFalmouth

References

Banks, K and Banks, N (2001).‘Chronicity, models, gurus – and coreskills’ (letter) Physiotherapy, 87, 2, 112.

Gifford, L S (ed) (1998). Topical Issuesin Pain 1. Whiplash Science andManagement: Fear avoidance beliefs andbehaviour, CNS Press, Falmouth.

Gifford, L S (ed) (2000). Topical Issuesin Pain 2. Biopsychosocial Assessment andManagement: Relationships and pain,CNS Press, Falmouth.

Linton, S J (1998). ‘The socio-economic impact of chronic low backpain: Is anyone benefiting?’ Pain, 75,163-168.

Pinnington, M A (2001). ‘Why are wefinding it so hard to change ourapproach to low back pain?’Physiotherapy, 87, 2, 58-59.

Sagan, C (1996). The Demon HauntedWorld: Science as a candle in the dark,Headline, London.

Waddell, G (1998). The Back PainRevolution, Churchill Livingstone,Edinburgh.

Physiotherapy March 2001/vol 87/no 3

Letters 165

I READ with interest the article byMacSween et al (2001) that examinedthe valid measurement of functionalcapacity as distinct from aerobiccapacity in patient groups. On aphilosophical note I question the valueof using estimated V̇O2 max as ameasure of aerobic capacity in clinicalgroups who are unlikely to be able to achieve this exercise intensity. An estimated V̇O2 max measurereflects a purely hypotheticalmaximum capacity rather than a truevalue. Perhaps V̇O2 peak is a morefunctional measure of capacity andtolerance taking into account factors of pain and motivation, whichas detailed in table 2 are importantfactors affecting exercise tolerance inindividuals with RA. The study findingspossibly support this reflection with asignificant relationship between V̇O2

peak and the number of shuttlescompleted, supporting the authors intheir stressing of the usefulness ofdeveloping a shuttle-walking test as ameasure of functional capacity.

The authors chose to validate theincremental shuttle-walking test (SWT)peak level against an estimatedextrapolated rate of maximum oxygenconsumption ( V̇O2 max) taken from the same shuttle-walking test.

I am concerned that they used a non-steady state functional exercise testto estimate V̇O2 max. The validity andreliability of extrapolation frommeasures obtained during this form ofnon-steady state exercise, in thispatient group, have not beendescribed, although oxygenconsumption during shuttle walkinghas been described in individuals withchronic lung disease. This brings intoquestion why the authors did notvalidate against an established criterionmeasure.

They mention a previous studywhich, as I understand it, attempts tovalidate this means of estimating V̇O2

max against another estimatedmeasure, the Åstrand nomogram(Åstrand, 1960). Certainly the findingsof the referenced study (MacSween,2001), as reported in this article, of alight positive bias are not surprising asa non-steady state extrapolation wouldbe expected to slightly overestimateV̇O2 max. However at the time ofwriting this study does not appear to bepublished. The validity of this methodof estimating V̇O2 max in women withrheumatoid arthritis (RA) from theSWT cannot be asserted.

I also wish to reiterate my concernfrom a previous letter that the correct

units are used when publishing inPhysiotherapy in order to maintain thestandards set in other peer reviewedjournals (I refer to rate of oxygenconsumption where the dot is missingfrom over the V).

Helen DawesMCSP MMedSciOxford Brookes University

References

Åstrand, I (1960). ‘Aerobic workcapacity in men and women withspecial reference to age’ ActaPhysiologica Scandinavica, 49, 169, 1-92.

Dawes, H (2000). ‘Expressing units ofmeasurement’ (letter) Physiotherapy, 86,3, 167.

MacSween, A (2001). ‘The reliabilityand validity of the Åstrand nomogramand linear extrapolation for derivingmax from submaximal exercise data’,Journal of Sports Medicine and PhysicalFitness (in press).

MacSween, A Brydson, G, Creed, Gand Capell, H A (2001). ‘A preliminaryvalidation of the 10-metre incrementalshuttle walk test as a measure ofaerobic capacity in women withrheumatoid arthritis’, Physiotherapy, 87,1, 38-44.

Aerobic Measurement – Maximum or peak?