Biomechanical investigation of the modified Tardieu Scale in assessing knee extensor spasticity poststroke

Objective The modified Tardieu Scale (MTS) is a clinical tool for the measurement of muscle spasticity. The present study aimed to investigate the relationship between the MTS and the slope of the work-velocity curve as a biomechanical measure in assessing knee extensor muscle spasticity in patients with stroke. Methods Thirty patients with stroke (22 female, 8 male; mean age 55.4 ± 12.0 years) participated in this study. The knee extensor spasticity was assessed with the MTS. An isokinetic dynamometer was used to move the knee passively from full extension to 90° flexion at speeds of 60°/s, 120°/s, 180°/s, and 240°/s to collect torque-angle data. The slope of the work-velocity curve was calculated using linear regression [J/(°/s)]. Results The mean of R2-R1 component of MTS was 19.73 (SD 29.85). The mean work significantly decreased as the speed increased (p < .001). The mean (SD) slope for the work-velocity curve was −0.83 (SD 0.73, range −2.6–0.3). There was no significant relationship between the R2-R1 and the slope of work-velocity curve (r = 0.09, p = .62). Conclusions The lack of significant relationship between the MTS and the slope of work-velocity curve may question the usefulness of the MTS as a valid measure of muscle spasticity after stroke.