Rigidity score is a domain of the global parkinsonian summary score. The rigidity score is determined using a modified version of the motor portion of the United Parkinson's Disease Rating Scale (mUPDRS). A trained nurse clinician scores rigidity based on the following 5 items:

1. Neck rigidity
2. Right arm rigidity
3. Left arm rigidity
4. Right leg rigidity
5. Left leg rigidity

Rigidity is scored based on the passive movement of extremities when participants are in a relaxed sitting position.

Each item is scored on a 5-point scale. The rigidity domain score is calculated by adding the ratings for the individual items, dividing my the maximum possible score for the domain, then multiplying by 100. The domain score ranges from 0 to 100, with higher scores reflecting more rigidity.

Rater responses for each item:

Note: This variable is not calculated if more than half of the items are missing.