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