The representations of 1st
KPC gait feature for non-PD control subjects and PD patients, respectively. (a) The 1st
KPC waveform of a selected non-PD control participant. (b) The 1st
KPC waveform of a selected PD patient in the "Drug-Off" state. (c) The 1st
KPC waveform of the same PD patient in the "Drug-On" state. The red circles and black squares represent the local maximums and minimums, which reflect the occurrences of mid-swings and heel strikes, respectively.