Figure 4From: A new instrumented method for the evaluation of gait initiation and step climbing based on inertial sensors: a pilot application in Parkinson’s diseaseTrunk acceleration during APAs in two representative subjects: control subject (a, b) and PD subject (c, d). Signals collected during the initiation of level walk (a, c) and stair ascension (b, d) are shown. APA onset, heel-off and toe-off are reported as red marks.Back to article page