Adaptability of anticipatory postural adjustments associated with voluntary movement

Figure 5 Example of biomechanical traces in “ipsilateral isolated stepping” and “ipsilateral stepping + arm raising sequence” with additional inertia (one trial in one representative subject). yP, yG, y’’G, y’G, Aw: Medio-lateral (ML) center of pressure and center of gravity displacement, ML center of gravity acceleration, ML center of gravity velocity and tangential wrist acceleration, respectively; t0, HO, FO, FC, tw: Onset variation of the yP trace from the reference line, swing heel off, swing foot off, swing foot contact and onset of raising, respectively; SW, ST: Swing and stance leg side, respectively; APAs, EXE: Anticipatory postural adjustments and stepping execution phase, respectively. Main postural variables were reported only in the traces of the “ipsilateral isolated stepping”; yPAPA, yGAPA, y’GAPA: Maximal center of pressure displacement, center of gravity displacement and velocity during APAs; yPFC, yGFC, y’GFC: Center of pressure displacement, center of gravity displacement and velocity at time of swing foot contact. Positive variation of the traces indicates displacement, velocity or acceleration towards the swing leg side. Negative variation of the traces indicates displacement, velocity or acceleration towards the stance leg side (from Yiou et al[32]).