hi ozy and hussam,

I would not recommend to use the AS or MAS. Both the ashworth (AS) and the modified ashworth scale (MAS) suffer from important limitations in grading spasticity.
Passive movement is measured at only one speed. therefore you can not differentiate between reflex mediated resistance and mechanical resistance (e.g. contracture, thixotrophy or changed visco elastic properties in the muscle)
a good review over the MAS and AS was written by pandayan and coworkers in 1999 and published in clinical rehabilitation.
A better instrument to measure spasticity may be the Tardieu scale (here passive movement is scored at three different velocities (slow, limb falling (gravity speed) and faster than gravity)
A trial comparing MAS and TS was published 2006 by Ada, again in clinical rehabilitation.

martin