Effects of postural threat on walking features of Parkinson's disease patients

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This study investigated whether or not gait kinematics among healthy older individuals and Parkinson's disease (PD) patients are influenced by postural threat. Eight healthy older individuals and eight PD patients were examined while walking at self-selected velocities, under three conditions of postural threat: unconstrained floor; constrained floor (19 cm wide); constrained and elevated floor (19 cm wide by 10 cm high). Independent of the surface conditions, due to motor disturbances caused by the PD these patients walked slower, with shorter strides, and spent more time in the double support phase and less time in the swing phase than did their matched controls. Increases in postural threat resulted in altered gait kinematics for all subjects. Specifically, stride length, stride velocity, cadence,and heel contact velocity decreased, and stride duration and double support duration increased relative to increases in postural threat. All gait alterations were the result of participants' attempts to facilitate locomotion control and maintain stability. The results of this study reveal that width and height constraints effectively perturbed the balance of all of the walking older individuals. The PD patients were able to modulate gait parameters when faced by a postural threat task. (C) 2009 Elsevier Ireland Ltd. All rights reserved.4522136140Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [05/03559-2]CNPq [133013/2006-5

Cognitive Correlates of Timed Up and Go Subtasks in Older People with Preserved Cognition, Mild Cognitive Impairment, and Alzheimer's Disease

Objective To determine whether impaired Timed Up and Go Test (TUG) subtask performances are associated with specific cognitive domains among older people with preserved cognition (PC), mild cognitive impairment (MCI), and mild Alzheimer's disease (AD). Design TUG subtasks performances were assessed by the Qualisys motion system. Cognition was assessed by Addenbrooke's Cognitive Examination and the Frontal Assessment Battery (FAB). Results The highest correlations with transition subtasks were with aspects of executive function, i.e. the fluency domain in the PC group (n = 40), FAB scores in the MCI group (n = 40), and the visuospatial domain in the AD group (n = 38). No significant associations were found between the walking subtasks and cognition in any group. Multivariate linear regression models identified the fluency domain as an independent predictor of turn-to-walk and turn-to-sit measures in the PC group, and the visuospatial domain as an independent predictor of turn-to-walk and turn-to-sit measures in the AD group, adjusted for age and sex. Conclusions Poorer executive functioning was associated with impaired transition mobility in all groups. The significant associations between visuospatial impairment and poor transition mobility in the AD participants may provide insight into why this group has an elevated fall risk

Executive functioning, concern about falling and quadriceps strength mediate the relationship between impaired gait adaptability and fall risk in older people

Background Reduced ability to adapt gait, particularly under challenging conditions, may be an important reason why older adults have an increased risk of falling. This study aimed to identify cognitive, psychological and physical mediators of the relationship between impaired gait adaptability and fall risk in older adults. Methods Fifty healthy older adults (mean ± SD: 74 ± 7 years) were categorised as high or low fall risk, based on past falls and their performance in the Physiological Profile Assessment. High and low-risk groups were then compared in the gait adaptability test, i.e. an assessment of the ability to adapt gait in response to obstacles and stepping targets under single and dual task conditions. Quadriceps strength, concern about falling and executive function were also measured. Results The older adults who made errors on the gait adaptability test were 4.76 (95%CI = 1.08–20.91) times more likely to be at high risk of falling. Furthermore, each standard deviation reduction in gait speed while approaching the targets/obstacle increased the odds of being at high risk of falling approximately three fold: single task − OR = 3.10,95%CI = 1.43–6.73; dual task − 3.42,95%CI = 1.56–7.52. Executive functioning, concern about falling and quadriceps strength substantially mediated the relationship between the gait adaptability measures and fall risk status. Conclusion Impaired gait adaptability is associated with high risk of falls in older adults. Reduced executive function, increased concern about falling and weaker quadriceps strength contribute significantly to this relationship. Training gait adaptability directly, as well as addressing the above mediators through cognitive, behavioural and physical training may maximise fall prevention efficacy

Gait spatial and temporal predictors for functional capacity tests in Parkinson's disease patients

Objective: To determine which spatial and temporal parameters are predictors of the gait pattern of individuals with idiopathic Parkinson's disease, for the aerobic endurance and agility tests included in the battery of tests of the AAHPERD protocol. Methods: Six men and six women with mild and moderate impairment and disease stage were selected. They performed agility and aerobic endurance test in accordance with the AAHPERD protocol, and walked 8 m on a walkway. A digital video camera recorded one central stride. Markers were attached to the fifth metatarsal and lateral face of the calcaneus of the right leg and to the first metatarsal and medial face of the calcaneus of the left leg. The dependent variables selected were the time taken in the agility and endurance tests and the kinematic variables: stride length (SL) cadence (CAD), stride time (ST), double support time (DS), single support time (SS), swing time (SW) and stride velocity (SV). Results: For agility, Pearson's test showed statistically significant correlations with SL (r=-0.70; p <= 0.05), CAD (r=-0.72; p <= 0.01), SV (r=-0.83; p <= 0.01), ST (r=0.71; p <= 0.01) and DS (r=0.90: p <= 0.01). For endurance, there were correlations with SL (r=-0.67; p <= 0.05), CAD (r=-0.72, p <= 0.01), SV (r=-0.82; p <= 0.01), ST (r=0.71; p <= 0.01), and DS (r=0.90; p <= 0.01). Multiple regression analysis revealed that DS was the only variable that predicted performance in both the agility (R-2=0.82; p <= 0.01) and the endurance (R-2=0.81; p <= 0.01) tests. Conclusions: It was observed that DS measure has a potential use as a kinematic parameter of gait that predicts the performance in agility and aerobic endurance tests in patients with idiopathic Parkinson's disease.12535936

Stepping reaction time and gait adaptability are significantly impaired in people with Parkinson's disease: Implications for fall risk

Background: Decline in the ability to take effective steps and to adapt gait, particularly under challenging conditions, may be important reasons why people with Parkinson's disease (PD) have an increased risk of falling. This study aimed to determine the extent of stepping and gait adaptability impairments in PD individuals as well as their associations with PD symptoms, cognitive function and previous falls. Methods: Thirty-three older people with PD and 33 controls were assessed in choice stepping reaction time, Stroop stepping and gait adaptability tests; measurements identified as fall risk factors in older adults. Results: People with PD had similar mean choice stepping reaction times to healthy controls, but had significantly greater intra-individual variability. In the Stroop stepping test, the PD participants were more likely to make an error (48 vs 18%), took 715 ms longer to react (2312 vs 1517 ms) and had significantly greater response variability (536 vs 329 ms) than the healthy controls. People with PD also had more difficulties adapting their gait in response to targets (poorer stepping accuracy) and obstacles (increased number of steps) appearing at short notice on a walkway. Within the PD group, higher disease severity, reduced cognition and previous falls were associated with poorer stepping and gait adaptability performances. Conclusions: People with PD have reduced ability to adapt gait to unexpected targets and obstacles and exhibit poorer stepping responses, particularly in a test condition involving conflict resolution. Such impaired stepping responses in Parkinson's disease are associated with disease severity, cognitive impairment and falls

Evaluating the Acute Contributions of Dopaminergic Replacement to Gait With Obstacles in Parkinson's Disease

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The influence of dopaminergic replacement (DR) on gait in people with Parkinson's disease (PD) is well documented. However, little is known about the acute effects of dopamine on more complex locomotor tasks that require visual guidance to avoid obstacles during gait. The authors investigated the influence of DR on locomotor behavior in a task where movement planning and control might be challenged by the height of the obstacle. The PD group included patients diagnosed with idiopathic PD (n = 12), as well as healthy controls (n = 12). Patients walked and stepped over obstacles of different heights before (OFF) and after (ON) levodopa intake. Spatial adjustments were not modulated by DR, but the step time to perform these anticipatory gait adjustments was longer only in PD-OFF (compared with healthy controls) when approaching the highest obstacle, but not PD-ON. During the crossing phase, trail limb toe clearance of PD patients was shorter than healthy controls only during the OFF state. ON-OFF comparisons were significantly different only for the time to reach the lead foot clearance over the highest obstacle. In summary, DR partially improved movement slowness but did not directly affect movement amplitude of lower limb regulation in this gait task.455369380Fundação para o Desenvolvimento da UNESP (FUNDUNESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2005/00775-6

Home-based step training using videogame technology in people with Parkinson’s disease: a single-blinded randomised controlled trial

© 2017, © The Author(s) 2017. Objectives: To determine whether 12-week home-based exergame step training can improve stepping performance, gait and complementary physical and neuropsychological measures associated with falls in Parkinson’s disease. Design: A single-blinded randomised controlled trial. Setting: Community (experimental intervention), university laboratory (outcome measures). Subjects: Sixty community-dwelling people with Parkinson’s disease. Interventions: Home-based step training using videogame technology. Main measures: The primary outcomes were the choice stepping reaction time test and Functional Gait Assessment. Secondary outcomes included physical and neuropsychological measures associated with falls in Parkinson’s disease, number of falls over six months and self-reported mobility and balance. Results: Post intervention, there were no differences between the intervention (n = 28) and control (n = 25) groups in the primary or secondary outcomes except for the Timed Up and Go test, where there was a significant difference in favour of the control group (P = 0.02). Intervention participants reported mobility improvement, whereas control participants reported mobility deterioration—between-group difference on an 11-point scale = 0.9 (95% confidence interval: −1.8 to −0.1, P = 0.03). Interaction effects between intervention and disease severity on physical function measures were observed (P = 0.01 to P = 0.08) with seemingly positive effects for the low-severity group and potentially negative effects for the high-severity group. Conclusion: Overall, home-based exergame step training was not effective in improving the outcomes assessed. However, the improved physical function in the lower disease severity intervention participants as well as the self-reported improved mobility in the intervention group suggest home-based exergame step training may have benefits for some people with Parkinson’s disease