Control of the Motions of the Body’s Center of Mass and End-Points of the Lower Limbs in Patients with Mild Parkinson’s Disease During Obstacle-Crossing
Neuromuscular impairments in Parkinson’s disease (PD) alter the mechanics and control of the body, leading to an increased risk of falling during more challenging functional tasks such as obstacle-crossing. However, little is known about these changes. The current study aimed to bridge the gap by quantifying the motion of the body’s center of mass (COM) relative to the center of pressure (COP) in terms of COM-COP inclination angles (IA) and their rate of change (RCIA) in fifteen older adults with mild PD and fifteen healthy controls when crossing obstacles of heights of 10, 20 and 30% leg length. There were no between-group differences for either the leading or trailing toe clearances (p > 0.05). With the unaffected limb leading, the PD subjects significantly increased the crossing sagittal and frontal IA, crossing sagittal RCIA, the peak RCIA, and average sagittal and frontal RCIAs during double-limb support for all obstacle heights when compared to those with the affected limb leading and those of the Controls (p < 0.05). The poor balance control in the mediolateral direction during obstacle-crossing in PD indicated an increased risk of falling. The differences in the crossing patterns between leading with the affected or unaffected limb suggest that patients with PD should lead with the affected limb when crossing obstacles. The current findings suggest that early dynamic balance training is important in the management of patients with PD.