Fig 1.
Schematic representation of the pendulum used to induce the postural disturbances.
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.
Table 1.
Characteristics of the participants with Parkinson’s disease.
Table 2.
Characteristics of the participants in the control group.
Fig 2.
Typical EMG patterns of the right gluteus medius (rGM) activity for two representative subjects (healthy control vs. patient with Parkinson’s disease).
The pointing down arrow at time 0 represents the moment of the pendulum impact against the subject’s shoulder.
Fig 3.
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).
*Significant differences between groups (P<0.05).
Fig 4.
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.
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.