Controlling modified Tardieu scale assessment speeds to match joint angular velocities during walking impacts spasticity assessment outcomes

Abstract

OBJECTIVE: To investigate whether tailoring the speed of the Modified Tardieu Scale to reflect an individual's joint angular velocity during walking influences spasticity assessment outcomes.

DESIGN: Observational trial.

SETTING: Inpatient and outpatient neurological hospital department.

SUBJECTS: Ninety adults with lower-limb spasticity.

INTERVENTIONS: N/A.

MAIN MEASURES: The Modified Tardieu Scale was used to assess the gastrocnemius, soleus, hamstrings and quadriceps. The V1 (slow) and V3 (fast) movements were completed as per standardised testing. Two additional assessments were completed, reflecting joint angular velocities during walking based on (i) a healthy control database (controlled velocity) and (ii) the individual's real-time joint angular velocities during walking (matched velocity). The agreement was compared using Cohen's and Weighted Kappa statistics, sensitivity and specificity.

RESULTS: There was poor agreement when rating trials as spastic or not spastic at the ankle joint (Cohen's Kappa = 0.01-0.17). Trials were classified as spastic during V3 and not spastic during the controlled conditions in 81.6-85.1% of trials when compared to stance phase dorsiflexion angular velocities and 48.0-56.4% when compared to swing phase dorsiflexion angular velocities. The severity of muscle reaction demonstrated poor agreement at the ankle (Weighted Kappa = 0.01-0.28). At the knee, there was a moderate-excellent agreement between the V3 and controlled conditions when rating a trial as spastic or not spastic (Cohen's Kappa = 0.66-0.84) and excellent agreement when comparing severity (Weighted Kappa = 0.73-0.94).

CONCLUSION: The speed of assessment impacted spasticity outcomes. It is possible that the standardised protocol may overestimate the impact spasticity has on walking, especially at the ankle.