Figure 8.

Mismatch between predictive and actual limb dynamics. (A) Percent mismatch between predictive versus actual estimates of passive joint dynamics (inertia, viscosity, stiffness) as a function of tremor severity (TAS score) in subjects with MS. The mismatch between actual and predicted limb dynamics increased with tremor assessment score. Error bars denote ± SD of the bootstrap distribution. (B) Percent mismatch between the parameters characterizing internal (predicted) and actual passive joint dynamics for subjects with MS (±SD), plotted against tremor power characterized using the spiral-tracing task. Percent mismatch increased as a saturating function of with tremor magnitude (red) for inertia and stiffness (R² > 0.70; p < 0.01) but not for viscosity (R² = 0.16; p = 0.32).