The degree of MCP joint flexion in both hands showed moderate correlation with the MDS-UPDRS-III motor score (r = 0.518, P < 0.001), mainly related to ipsilateral rigidity and ipsilateral bradykinesia scores, and fair correlation with the Hoehn-Yahr stage.
Rigidity measured using our instrument had moderate agreement with the MDS-UPDRS and showed differences between therapeutic state, activation conditions, and disease/healthy cohorts.