Purpose: Rigidity is a cardinal symptom of Parkinson's disease (PD) and is often clinically assessed by passively flexing and extending a patient's limb. Objective measurements had been employed to examine rigidity in PD subjects, including wrist, elbow, knee and trunk. This study aimed to investigate the relationship between an objective measurement of trunk rigidity and health-related quality of life (HRQoL) and functional status in patients with mild to moderate PD.
Methods: An isokinetic dynamometer Biodex System 3 was employed to assess trunk rigidity in 36 PD patients. HRQoL was assessed with the EuroQol-5D and Parkinson's Disease Questionnaire-39 items (PDQ-39). Functional status was measured with the Schwab and England scale.
Results: Trunk rigidity was correlated with the HRQoL assessed with the mobility, cognition and stigma PDQ-39 domains and the total PDQ-39 scores. No correlations were found among trunk muscle tone assessed with the isokinetic dynamometer and the EuroQoL-5D. Functional status was correlated with the trunk extensors rigidity at all angular velocities.
Conclusion: The results from this study suggest that the axial motor impairments impact on QoL and functional status in patients with PD. Further studies are needed with quantitative devices for axial rigidity assessment to determine the relationship between trunk rigidity in PD patients with higher disease severity and HRQoL scales.