The Assessment of Upper Limb Functionality in Friedreich Ataxia via Self-Feeding Activity

The objective assessment of motor impairment resulting from neurological disorders forms the basis for effective rehabilitation and therapeutic programs. Such assessments conducted through the engagement of suitable daily activities can serve as an effective surrogate measure for the assessment of independent living. This study considers an instrumented spoon in the assessment of upper-limb functionality through the self-feeding activity of a group of individuals clinically diagnosed with the debilitating condition, Friedreich ataxia (FRDA). Thirty-five subjects with FRDA (34 ± 14 years old) and 14 age-matched healthy subjects performed three cycles of self-feeding consisting of grasping, scooping, transferring food to mouth and returning the spoon. Parameters relating to the feeding rate, trajectory of the rotation, range of motion and movement variability with specific attention to each segment were considered for the capture of ataxia pertaining to the disability. Movement variability measured by Dynamic Time Warping (DTW) resulted in an average accuracy of 96% in the diagnosis of ataxia (separation of the two cohorts). The severity of ataxia estimated using a combination of features from Random Forest (RF) increased the correlation with the clinical estimates of ataxia by 13% and achieved higher coefficient (0.72 in patient scale) than the currently used tests (Box & Block, Pegboard). While the overall results provided an objective, daily activity based means of capturing intrinsic abnormalities, the different segments of the task demonstrated the presence of ataxia in a spatial context concurring with relevant clinical observations.