Age and Parkinson's disease related kinematic alterations during multi-directional gait initiation.

Previous literature suggests that older adults and persons with Parkinson's disease (PWP) exhibit impaired performance during gait initiation (GI) and turning while walking. While researchers have identified specific impairments during GI and turning separately in these populations, little is known about when these two tasks occur concurrently. Our objective was to determine how multi-directional GI kinematics are affected by aging and Parkinson's disease. Kinematic data were collected on 12 healthy young adults (HYA), 11 healthy older adults (HOA) and 11 PWP during GI in four conditions: forward, medial 45°, lateral 45°, and lateral 90°. Spatiotemporal characteristics and segmental angles were analyzed using separate 3 (group)×4 (condition) mixed ANOVA. Combined across all the conditions, HOA took a smaller (P=0.009) and slower (P=0.023) first step, and slower second step (P=0.021) compared to HYA. PWP took a slower first step (P=0.009), and longer time to initiate the second step (P=0.017) compared to HOA. Also, PWP had greater head rotation at the start of GI during the medial 45° condition (P=0.043) and reduced overall segmental rotation before toe-off of the second step during the lateral 45° condition (P=0.035), and at heel-strike of first step (P=0.031) and before toe-off of second step during lateral 90° condition (P=0.035). For HOA, their general slowness of movement could be attributed to aging effects. For PWP, rigidity and bradykinesia could impair activities of daily living like multi-directional GI and may be associated with an increased risk of falls.