Complexity of the environment and asymmetry on the gait in elderly with Parkinson's disease

Abstract

PD is a chronic and progressive neurodegenerative disease characterized by the death of dopaminergic neurons in the substantia nigra compact part, responsible for the production of dopamine. This situation causes the signs and symptoms of Parkinson's disease (PD). Furthermore, several studies have found changes in locomotion patterns of older people with PD, especially during the transposition of obstacles. Studies have found greater instability during obstacle avoidance, increasing the risk of touching the obstacle and thus increasing the risk of trips and falls in older people with PD. In addition, the presence of more than one obstacle requires different modulations in standard locomotion compared to walking with only one obstacle. Few studies have examined the gait of elderly with PD in environments with more than one obstacle. Moreover, other factor that is overlooked in studies with obstacle avoidance in elderly with PD is the member used to step over the obstacle; i.e., the asymmetry between members for overstepping. Therefore, the objective of this study is: a) to analyze the influence of the complexity of the environment based on gait's spatial and temporal parameters of older adults with PD comparing them with neurologically healthy elderly; b) to analyze the effect of impairment of lower limb in asymmetry on the gait of elderly with PD during transposition of one or two obstacles and to compare with neurologically healthy elderly. Forty subjects will participate in this study, 20 elderly patients with PD and 20 neurologically healthy elderly. The elderly will be selected from the community where the study will be conducted. The task is to walk in preferred speed on a 8-meter pathway. Two studies will be performed. The conditions of the gait analyzed will be: regular environment, environment with an obstacle, environment with two obstacles with a step distance between them and environment with two obstacles in sequence (only in study II). In study I, participants with PD should use the less affected leg by the disease to step over the obstacle and neurologically healthy elderly the dominant leg. In study II, the stepping over the obstacle will be performed with both members. Three trials will be performed for each condition. The trials will be randomized in blocks. For the acquisition of gait parameters optoelectronic motion analysis (Optotrack®) and a carpet with pressure sensors (GAITrite®) will be used. Two force platforms (AMTI ®) will be placed on the catwalk for the acquisition of the kinetic parameters. MANOVA with factors for group, task and asymmetry (study II) to answer the questions of the study will be applied.