[rd42]

I keep reading documents about the UPDRS and for example tremor is "measured" by this scale.

Tremor at rest (head, upper and lower extremities)
0 = Absent.
1 = Slight and infrequently present.
2 = Mild in amplitude and persistent. Or moderate in amplitude, but only intermittently present.
3 = Moderate in amplitude and present most of the time.
4 = Marked in amplitude and present most of the time.

What I don't understand and can't seem to find are the instructions on how the examiner determines what "marked amplitude" is and how is "marked amplitude defined" The same goes for some of the other motion tests. Have any of you seen documentation on how doctors are taught to determine these values?

Thanks,
rd42