Excellent test-retest and inter-rater reliability for Tardieu Scale measurements with inertial sensors in elbow flexors of stroke patients

Background: Spasticity is often clinically assessed with the Tardieu Scale, using goniometry to measure the range of motion and angle of catch. However, the test-retest and inter-rater reliability of these measurements have been questioned. Inertial sensors (IS) have been developed to measure orientation in space and are suggested to be a more appropriate tool than goniometry to measure angles in Tardieu Scale measurements. Objective: To compare the test-retest and inter-rater reliability of Tardieu Scale scores measured with IS and goniometry. Methods: Two physiotherapists performed Tardieu Scale measurements in two sessions, using both goniometry and IS, to quantify spasticity in elbow flexors of 13 stroke patients. Results: For goniometry, test-retest and inter-rater reliability proved to be excellent (ICC 0.86) and fair to good (ICC 0.66), respectively. For IS, both test-retest (ICC 0.76) and inter-rater reliability (ICC 0.84) were excellent. Conclusions: Inertial sensors are reliable and accurate to use in Tardieu Scale measurements to quantify spasticity in the elbow flexors of hemiplegic stroke patients.