Physiotherapy November 2001/vol 87/no 11

601Abstracts

Findings There was no evidence found in the literature to discriminate between symptoms of neurogenic in-flammation and chemically mediated inflammation. There were also no studies demonstrating the incidence of neurogenic inflammation in musculoskeletal medicine.

Discussion It may be that the symptoms of inflammation donot vary with the different mediator mechanisms and assuch no differences have been noted. However the lack ofclinical studies in this field may also contribute to the lackof symptom differentiation. Neurogenic inflammation maybe a possible mechanism for pain in the musculoskeletalfield which may so far have been unrecognised.

Conclusion There are many physiological studies demon-strating the existence of neurogenic inflammation in theanimal model but none linking clinical symptoms andpathophysiology. The lack of understanding and awarenessof the role of neurogenic inflammation in the musculo-skeletal field demonstrates a need for further investig-ation as the implications for diagnosis and treatment maybe significant.

Reference

Daemen et al (1998). ‘Neurogenic inflammation in theanimal model of neuropathic pain’, Neurology Research, 20, 1,41-45.

Analgesic Effects of InterferentialTherapy Current on Cold-PressorPain in Healthy Subjects Single blind trial of three interferentialcurrents against sham interferentialcurrents and control

E M Walker, R Stephenson University of East AngliaIntroduction Interferential (IF) therapy is well doc-umented as a therapeutic medium for pain relief. Despitewidespread use by physiotherapists, there remains verylimited laboratory or clinical evidence for its analgesiceffect. This study investigated the analgesic effect of IF onrepeated cycles of cold-pressor pain.

Method Fifty healthy, pain-free IF-naïve volunteers wererandomly allocated to one of five ‘treatment’ groups (n = 10),comprising control group (no treatment throughout); IF100 Hz applied to the ipsilateral limb; IF 100 Hz applied tothe contralateral limb; IF 30 Hz applied to the ipsilaterallimb; and sham IF applied to the ipsilateral limb.

Pain threshold scores were recorded for all six ‘pain’cycles, with IF ‘treatment’ added during cycles 3 to 6.Baseline (pre-treatment) pain threshold was subtractedfrom subsequent (during-treatment) threshold values toprovide a measure of treatment effect.

Results Pain threshold values for all groups were raised withthe exception of the control group; pain threshold valuesfor the control group decreased across the cycles. Painthresholds within IF treatment groups were repeatedlyraised, but no more than with sham IF. IF at 30 Hz and 100 Hz applied to the contralateral limb offered moreconsistency in the rise in mean values relative to standarddeviation, with the sham group demonstrating morevariation in performance.

Repeated measures ANOVA scores for two mixed factorsfailed to show any significant differences for the treatmenteffects either within groups across cycles (Greenhouse-Geisser, p = 0.123) or between groups across cycles(Greenhouse-Geisser, p = 0.552). Thus, the trends observedin the data set were not shown as statistically significantdifferences at the 5% level.

Discussion/Conclusion The study failed to demonstratethat IF has any statistically significant influence on painthreshold when compared to non-intervention controls orsubjects receiving sham IF. Apparent differences in painthreshold profiles across the groups suggest that both shamIF and IF stimulation do result in higher pain thresholdvalues compared to control groups. IF stimulation offers agreater magnitude of change across repeated exposurethan sham IF. There is a clear need for further research inboth laboratory and clinical settings.

Why Don’t All Chronic LowBack Pain Patients ImproveFollowing Rehabilitation?S R Woby, N K Roach, K M Birch Manchester Metropolitan University

P J Watson University of ManchesterIntroduction The process that mediates clinicallyimportant changes in disability following chronic low backpain (CLBP) rehabilitation has yet to be substantiated.

According to the cognitive-behavioural approach, changesin disability are related to changes in patients’ beliefs andcognitions. Consequently, the aim of this study was toexplore the relationship between changes in these cognitivefactors and clinically important changes in disability.

Method Data were gathered from 68 CLBP patients whohad been referred to a physiotherapy-led intervention thatemployed cognitive-behavioural principles, in combinationwith exercise and education.

Upon admission to the programme patients completed abattery of measures that assessed pain, disability andpertinent cognitive factors associated with CLBP, eg fears,