Decomposition of Reaching Movements Enables Detection and Measurement of Ataxia

Table 2 The ten data features with the strongest Pearson correlation coefficients (r) with respect to the clinician-assessed Brief Ataxia Rating Scale scores. All correlations have p < 0.01

r	Feature description
-0.73	Mean of movement element distances (in the log scale).
0.72	Interquartile range of the (log) ratios of consecutive movement element distances. Higher values correspond to less consistency in the distances traveled during consecutive submovements.
-0.72	The power-law scaling exponent (α) between movement element distances and mean speeds.
-0.71	Median of movement element (log) distances.
-0.69	Median of movement element (log) mean speeds.
-0.69	Mean of movement element (log) mean speeds.
0.65	Density of small consecutive movement elements with different sizes and the same direction (towards the tablet). Higher values likely correspond to small, more segmented movements during the reaching behavior.
-0.64	Ninetieth percentile of movement element (log) mean speeds.
0.64	Density of small consecutive movement elements with the same size and direction (towards the tablet). Higher values likely correspond to small, more segmented movements during the reaching behavior.
0.63	Standard deviation of the (log) ratios of consecutive movement element distances. (i.e., Higher values correspond to less consistency in the distances traveled during consecutive submovements