Antonella Tatarelli (Italy)
Istituto Nazionale per l'Assicurazione contro gli Infortuni sul Lavoro-INAIL Department of Occupational and Environmental Medicine, Epidemiology and HygieneAuthor Of 1 Presentation
ABILITY OF A SET OF TRUNK ACCELERATION-DERIVED GAIT STABILITY INDEXES TO IDENTIFY GAIT UNBALANCE AND RECURRENT FALLERS IN SUBJECTS WITH PARKINSON’S DISEASE.
- Stefano Filippo Castiglia (Italy)
Abstract
Background and Aims:
Gait abnormality is one of the most invalidating features of subjects with Parkinson’s disease (PD) which leads to a high risk of falls, impairs patients’ autonomy and decreases quality of life. The aims of this study were: (i) to assess the ability of 16 gait stability indexes to identify gait instability and recurrent fallers in persons with Parkinson’s Disease (pwPDs) irrespective of age and gait speed and (ii) to investigate their correlation with clinical and kinematic variables.
Methods:
Fifty-five walking trials from subjects with PD and 55 age-and-speed matched healthy subjects (HS) acquired with an inertial sensor system and included in the study. Based on the acceleration patterns provided by the inertial measurement unit, we calculated the harmonic ratios (HR), percent recurrence and percent determinism (RQAdet), coefficient of variation, normalized jerk score and the longest Lyapunov exponent.
Results:
A value ≤ 1.50 at the HR in the antero-posterior direction (HRAP) discriminated between pwPDs subjects at Hoehn & Yahr stage (HY) 3 and HS with a 67% probability, between pwPDS at HY 3 and pwPDs at lower HY stages with a probability of 73% and it identified recurrent fallers with a probability of 77%. HRAP correlated with pelvic obliquity and rotation. RQAdet in the AP direction discriminated between pwPDs and HS with a 67% probability, irrespective of the HY stage and was correlated with stride duration and cadence. 
Conclusions:
HRAP and RQAdet in the AP direction can be used as age- and speed-independent markers of gait instability.