Characteristics of the participants in the control group.

<p>Characteristics of the participants in the control group.</p

Means and standard errors of the center of pressure displacement in mediolateral (COPml) (right panel) and anteroposterior directions (COPap) (left panel) for the control and PD groups during the 4 time intervals for anticipatory (APA1 and APA2) and compensatory (CPA1 and CPA2) postural adjustments.

<p>The positive and negative signs in mediolateral direction represent the left and right sides, respectively. The positive signs denote anterior displacement while negative signs represent posterior excursion.</p

Anticipatory (APA1 and APA2) and compensatory (CPA1 and CPA2) time intervals for the GM, EO and PE right and left lateral muscles for each group (average across 13 subjects).

<p>*Significant differences between groups (P<0.05).</p

Characteristics of the participants with Parkinson’s disease.

<p>Characteristics of the participants with Parkinson’s disease.</p

Schematic representation of the pendulum used to induce the postural disturbances.

<p>The participants kept their head rotated 30 degrees toward the pendulum. 1: pendulum, 2: pulley system, 3: load attached to the pendulum, 4: ball and the accelerometer, 5: distance of the pendulum release (0.8 m), 6: safety belt.</p

Characteristics of the participants in the control group.

<p>Characteristics of the participants in the control group.</p