How does the Tardieu spasticity assessment differ from the Modified Ashworth Scale?

• A. Tardieu measures range of motion; MAS measures strength.
• B. MAS assesses resistance at a single, slow speed.
• C. Tardieu assesses resistance at multiple speeds (R1 vs R2) to separate dynamic from fixed contractures and detects clonus; MAS assesses resistance at a single, slow speed.
• D. Tardieu is used only for adults; MAS only for children.

Answer: (C)

The key idea is that spasticity assessment depends on how resistance to movement changes with speed, helping differentiate neural spasticity from fixed muscle shortening. The Tardieu scale measures resistance at multiple speeds, capturing both a slow stretch (R2) and a fast stretch (R1). By comparing these angles, you can see if there’s a velocity-dependent catch characteristic of spasticity (R1 smaller than R2) and you can observe clonus at rapid stretch. This lets you separate dynamic (neural) components from fixed contractures.

In contrast, the Modified Ashworth Scale uses a single, slow-speed passive movement to rate resistance on a single scale. It doesn’t assess how resistance changes with speed and can’t reliably distinguish whether the resistance comes from neural factors or from a contracture, nor does it capture clonus.

So the best description is that the Tardieu assesses resistance at multiple speeds (R1 vs R2) to separate dynamic from fixed contractures and can detect clonus, while MAS assesses resistance at a single, slow speed.