Journal of Rehabilitation Medicine 51-1CompleteIssue | Page 57

J Rehabil Med 2019; 51: 54–60 ORIGINAL REPORT INTER- AND INTRA-RATER VARIABILITY OF TESTING VELOCITY WHEN ASSESSING LOWER LIMB SPASTICITY Megan BANKY, BAppSci 1,2 , Ross A. CLARK, PhD 2 , Yong-Hao PUA, PhD 3 , Benjamin F. MENTIPLAY, PhD 1,4,5 , John H. OLVER, MBBS 6 and Gavin WILLIAMS, PhD 1,7 Department of Physiotherapy, Epworth HealthCare, Melbourne, 2 School of Health and Sport Sciences, University of the Sunshine Coast, Sunshine Coast, Australia, 3 Department of Physiotherapy, Singapore General Hospital, Singapore, Singapore, 4 La Trobe Sport and Exercise Medicine Research Centre, La Trobe University, 5 Victorian Infant Brain Studies, Murdoch Children’s Research Institute, 6 Epworth Monash Rehabilitation Medicine Unit, and 7 Department of Physiotherapy, University of Melbourne, Melbourne, Australia 1 Objective: To establish the variability of fast testing velocity and joint range of motion and position when assessing lower-limb spasticity in individuals follo- wing neurological injury. Design: Observational study of people with lower- limb spasticity. Subjects: Patients with an upper motor neurone le- sion (n  = 35) and clinicians experienced in spasticity assessment (n  = 34) were included. Methods: The Modified Tardieu scale (MTS) was com- pleted on the quadriceps, hamstrings (2 positions), gastrocnemius and soleus for each participant’s more affected lower limb by 3 assessors. Mean ab- solute differences (MADs) were used to calculate va- riability as a measure of reliability. Results: Variability of peak testing velocity was greater at the ankle joint compared with the knee joint. The greatest MAD for V3 (fast) inter-rater tes- ting velocity was 119°/s in the soleus, representing 29.4% of the mean variable value, and least for the quadriceps (64.3°/s; 18.5%). Inter-rater variability was higher than intra-rater variability for all testing parameters. The MAD for joint end angle ranged from 2.6° to 10.7° and joint start angle from 1.2° to 14.4°. Conclusion: There was a large degree of inter- and intra-rater variability in V3 testing velocity when using the MTS to assess lower limb spasticity. The inter-rater variability was approximately double the intra-rater variability. Key words: rehabilitation; lower extremity; central nervous system diseases; reproducibility of results; muscle spasticity; outcome assessment. Accepted Sep 20, 2018; Epub ahead of print Nov 28, 2018 J Rehabil Med 2019; 51: 54–60 Correspondence address: Gavin Williams, Physiotherapy Department, Epworth Rehabilitation, 29 Erin Street, Richmond VIC 3121, Australia. E-mail: [email protected] N eurological injuries, such as stroke, traumatic brain injury and multiple sclerosis, are highly prevalent and place a large burden on the healthcare system (1, 2). Due to the high prevalence of spasticity (3–6), the financial strain it places on the healthcare sector (7, 8), and the impact it has on patient outcomes and quality of life (5, 9), the accurate assessment and LAY ABSTRACT Spasticity is prevalent in many neurological conditions in adults. Accurate assessment of spasticity is important in order to inform clinical decision-making and treat- ment options. Testing speed is a key component of the spasticity assessment process, but the reliability of how quickly the modified Tardieu Scale is performed has not been reported. This study found that the reliabi- lity of testing speed varied between lower-limb muscle groups, and variability was twice as great for inter-rater reliability as it was for intra-rater reliability. These fin- dings have implications for the accurate identification of lower-limb spasticity, and its contribution to mobility limitations. management of spasticity has become a major focus of neurological rehabilitation. Clinical measures of spasticity, such as the Modified Ashworth Scale (MAS) and the Modified Tardieu Scale (MTS) are quick and easy to perform with minimal equipment and are used to guide clinical decision-making for interventions such as botulinum neurotoxin A (BoNT-A) injections (10–12). The international consensus statements for the management of disorders of tone recommend the use of the MTS over the MAS as the MTS can more accura- tely differentiate spasticity from hypertonia (13, 14). When using the MTS, it has been recommended that the following 3 factors are required to rate the intensity of a spastic response: (i) the strength and duration of the stretch reflex (i.e. X value); (ii) the angle at which the stretch reflex is activated (i.e. R1); and (iii) the velocity necessary to trigger the stretch reflex (15, 16). Studies investigating the reliability of the Tardieu Scale or MTS have primarily reported the inter-rater and intra-rater reliability of the R1, R2 and spasticity angles, with some studies reporting the reliability of the X value (17–22). In comparison, the testing velocity has received little attention and the psychometric properties of the testing velocity during the MTS remain unknown. It is reasonable to suggest that the velocity of assess- ment may impact the stretch reflex (18); however, the application of the test in relation to velocity appears to be inconsistent and is likely to vary, depending on the instructions provided to the assessors, the assessor’s This is an open access article under the CC BY-NC license. www.medicaljournals.se/jrm doi: 10.2340/16501977-2496 Journal Compilation © 2019 Foundation of Rehabilitation Information. ISSN 1650-1977