Inter- and intra-rater variability of testing velocity when assessing lower limb spasticity
Journal of Rehabilitation Medicine
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 treatment 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 reliability of testing speed varied between lower-limb muscle groups, and variability was twice as great for
... wice as great for inter-rater reliability as it was for intra-rater reliability. These findings have implications for the accurate identification of lower-limb spasticity, and its contribution to mobility limitations. Objective: To establish the variability of fast testing velocity and joint range of motion and position when assessing lower-limb spasticity in individuals following neurological injury. Design: Observational study of people with lowerlimb spasticity. Subjects: Patients with an upper motor neurone lesion (n = 35) and clinicians experienced in spasticity assessment (n = 34) were included. Methods: The Modified Tardieu scale (MTS) was completed on the quadriceps, hamstrings (2 positions), gastrocnemius and soleus for each participant's more affected lower limb by 3 assessors. Mean absolute differences (MADs) were used to calculate variability 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 testing 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.