Figure 2.

Illustrative examples of walking clinimetric test sensor data recorded using a smartphone accelerometer from healthy individuals and those with PD. Left column: walking tests from PD patients, right column: healthy individuals. The horizontal axis represents time in seconds (approximately 30 s) and the vertical axis (orange, red and blue) three-axis acceleration (m/s${}^2$). Grey shaded areas: data segments in which the user is hand-labeled as adhering to the test protocol. (a) PD patient walking throughout the test; (b) healthy individual walking throughout the test; (c) smartphone buzzer inn the first few seconds of the test, PD patient walking throughout the test; (d) buzzer recorded in the first few seconds of the test, healthy individual walking throughout the test; (e) buzzer recorded in the first few seconds of the test; the PD patient deviates from the test protocol before adhering to the test instructions by starting to walk, near the end of the test; the PD patient deviates from the test protocol; (f) buzzer captured in the first few seconds of the test; the healthy individual then begins walking, after which the individual deviates from the test protocol and resumes walking near the end of the test; (g,h) the PD patient and healthy individual both deviate from the test instructions throughout the test.