Stop using the Ashworth Scale for the assessment of spasticity
- J F M Fleuren1,2,
- G E Voerman1,3,4,
- C V Erren-Wolters1,
- G J Snoek1,2,
- J S Rietman1,2,5,
- H J Hermens1,6,
- A V Nene1,2
- 1Roessingh Research and Development, Enschede, The Netherlands
- 2Rehabilitation Centre Het Roessingh, Enschede, The Netherlands
- 3Scientific Institute for Quality of Healthcare, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
- 4Department of Health Technology and Services Research, Faculty of Business, Public Administration and Technology, Twente University, Enschede, The Netherlands
- 5Faculty of Engineering Technology, Twente University, Enschede, The Netherlands
- 6Faculty of Electrical Engineering, Mathematics and Computer Science, Twente University, Enschede, The Netherlands
- Correspondence to J F M Fleuren, Roessingh Research and Development, PO Box 310, 7500 AH Enschede, The Netherlands, j.fleuren{at}rrd.nl
- Received 4 March 2009
- Revised 22 June 2009
- Accepted 24 June 2009
- Published Online First 21 September 2009
Abstract
Aim: Many studies have been performed on the methodological qualities of the (modified) Ashworth Scale but overall these studies seem inconclusive. The aim of this study was to investigate the construct validity and inter-rater reliability of the Ashworth Scale (AS) for the assessment of spasticity in the upper and lower extremities.
Method: A cross-sectional study on spasticity in the elbow flexors (part 1) and knee extensors (part 2) was carried out. In both parts AS was assessed while muscle activity and resistance were recorded simultaneously in patients with upper motor neuron syndrome. Each patient was measured by three raters.
Results: 30 patients participated, 19 in each part of the study. For elbow flexor muscles, AS was not significantly associated with electromyographic parameters, except for rater 2 (rho = 0.66, p<0.01). A significant moderate association was found with resistance (0.54⩽ rho ⩽0.61, p<0.05). For knee extensors, AS scores were moderately associated with muscle activity (0.56⩽ rho ⩽0.66, p<0.05) and also with resistance (0.55⩽ rho ⩽0.87, p<0.05). The intraclass correlation coefficient for absolute agreement was 0.58 for elbow flexors and 0.63 for knee extensors. In linear mixed model analysis, the factor rater appeared to be highly associated with AS.
Conclusion: The validity and reliability of the AS is insufficient to be used as a measure of spasticity.
Footnotes
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See Editorial Commentary, p 2
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Competing interests None.
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Ethics approval The study was approved by the medical ethics committee of the Rehabilitation Centre.
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Patient consent Obtained.
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Provenance and Peer review Not commissioned; externally peer reviewed.
