Effects of postural threat on walking features of Parkinson's disease patients (original) (raw)
Related papers
Archives of physical medicine and rehabilitation, 2017
To characterize anticipatory postural adjustments (APA) across a variety of step initiation tasks in people with Parkinson's disease (PD) and healthy control (HC). Cross-sectional study. Step initiation was analyzed during a) self-initiated gait, b) perceptual cued gait, and c) compensatory forward stepping after platform perturbation. People with PD were assessed On and Off levodopa. University research laboratory. PD (n=19) and healthy aged matched controls (n=12). Not applicable. Medio-lateral (ML) size of APA (calculated from center of pressure recordings), step kinematics and body alignment. With respect to self-initiated gait, the ML size of APAs were significantly larger during the cued condition and significantly smaller during the compensatory condition (p<0.001). HC and patients with PD did not differ in body alignment during the stance phase prior to stepping. No significant group effect was found for ML size of APA between HC and patients with PD. However, the red...
Archives of Physical Medicine and Rehabilitation, 2017
Objective-To characterize anticipatory postural adjustments (APA) across a variety of step initiation tasks in people with Parkinson's disease (PD) and healthy control (HC). Design-Cross-sectional study. Step initiation was analyzed during a) self-initiated gait, b) perceptual cued gait, and c) compensatory forward stepping after platform perturbation. People with PD were assessed On and Off levodopa. Setting-University research laboratory. Participants-PD (n=19) and healthy aged matched controls (n=12). Interventions-Not applicable. Main Outcome Measures-Medio-lateral (ML) size of APA (calculated from center of pressure recordings), step kinematics and body alignment. Results-With respect to self-initiated gait, the ML size of APAs were significantly larger during the cued condition and significantly smaller during the compensatory condition (p<0.001). HC and
Purpose: Walking pattern in patients with Parkinson's disease (PD) is abnormal, and dynamic balance of these patients is not clear yet. The objective of this study was to analyze the dynamic balance of patients with PD during walking and comparing it with normal elderly individuals. Methods: This is an Ex-post - facto research study design. Twelve male patients with PD (mean age: 64.0±7.8 y; mean height: 165.0±7.0 cm; mean mass: 65.3±10.3 kg; and mean BMI: 24.1±3.6 kg/m2) and 12 healthy male subjects as the peer group with matched age, height, weight, and BMI participated in this study. All subjects were chosen using convenience sampling method. Vicon motion analysis system was used to analyze temporal variables and center of mass (COM) displacement of the subjects during walking. Data were analyzed in SPSS-19 using independent t test with P<0.05. Results: Stride length and walking speed was significantly smaller in patients with PD than that in peer group (P<0.05). Mediolateral displacement of COM was not different between the two groups (P>0.05). However, posterioanterior and vertical displacements of COM were significantly smaller in patients with PD. Conclusion: Stride length, walking speed, as well as the posterioanterior and vertical displacement of COM in patients with PD were lower than those variables in normal subjects. These changes might be considered as a compensatory response of neuromuscular system to the affected dynamic postural control in these patients.
Motor adjustments during time-constrained sit-to-walk in people with Parkinson's disease
Experimental Gerontology, 2019
Sit-to-walk (STW) is a sequential task and a merge of sit-to-stand (STS) and gait initiation that are impaired in people with Parkinson's disease (PD). Performing sequential task under time constraint (e.g., stand up and walk to answer an urgent call) might influence people with PD due to their deficits on internal regulation of continuous, rhythmic and fast movements. It is known the PD behavior during STS and gait initiation tasks are impaired, however, little is known regarding PD behavior on STW. Thus, the aim of this study was to assess the motor behavior of people with PD and healthy older adults during the STW task under time constraint. Methods: Fourteen people with idiopathic PD and 14 healthy older adults (OA) participated in this study. They performed the STW task under a time constraint. STW performance (STW total duration, duration of each of the 4 phases of the STW, and the drop in the center of mass (COM) momentum, identified as Fluidity Index-FI), kinematics and kinetics outcomes were assessed throughout the task. Results: The PD group showed increased STW total time and lower FI, longer seat-off (Phase 1) time and first step (Phase 4) when compared to the OA group. Furthermore, the PD group showed more motor impairments (kinematics and kinetics) than the OA group throughout the task from seat-off until heel-off. Also, people with PD exhibited larger mediolateral COM displacement in the standing phase (Phase 2) and greater ground reaction force (GRF) in Phases 1 and 3. Conclusions: We observed that people with PD exhibited more restrictions when compared with healthy older adults on their STW performance, COM and GRF parameters during the STW under time constraint. Some clinical impairments usually observed in people with PD might explain their STW performance such as, motor planning deficits, less automatic motor control and mediolateral balance impairments.
Postural preparation prior to stepping in patients with Parkinson's disease
Journal of Neurophysiology, 2011
People with Parkinson's disease (PD) frequently have difficulties with generating anticipatory postural adjustments (APAs) for forward propulsion and lateral weight transfer when initiating gait. This impairment has been attributed to deficits in motor planning and preparation. This study examined the preparation of APAs prior to an imperative cue to initiate forward stepping. A startling acoustic stimulus (SAS) was used to probe the state of preparation of the APA in eight PD (off medication) and seven matched control subjects. Subjects performed visually cued trials involving a pre-cue light instructing them to prepare to step, followed 3.5 s later by a go-cue light to rapidly initiate stepping. In random trials, a SAS (124 dB) was presented at −1,500, −1,000, −500, −250, −100, or 0 ms before the go-cue. Subjects also performed self-initiated steps. Ground reaction forces (GRFs), center of pressure (CoP) changes, and electromyographic (EMG) signals were recorded. The SAS trigg...
Imposed faster and slower walking speeds influence gait stability differently in Parkinson fallers
Archives of physical medicine and rehabilitation, 2016
This cross-sectional study sought to evaluate the effect of imposed faster and slower walking speeds on postural stability in people with Parkinson's disease (PD). Cross-sectional cohort study; SETTING: General community PARTICIPANTS: 84 PD patients (51 with a falls history; 33 without) and 82 age-matched controls were invited to participate via neurology clinics and pre-existing databases. Of those contacted, 99 did not respond (PD=36; controls=63) and 27 were not interested (PD=18; controls=9). Following screening, a further 10 patients were excluded; 5 had deep brain stimulation surgery and 5 could not accommodate to the treadmill. The remaining 30 patients completed all assessments and were sub-divided in PD fallers (n=10), PD Non-Fallers (n=10) and age-matched controls (n=10) based on falls history. Symptom severity, balance confidence and medical history were established prior to participants walking on a treadmill at 70%, 100% and 130% of their preferred speed. Three-dime...
Dynamic postural stability during sit‐to‐walk transitions in Parkinson disease patients
Movement Disorders, 2008
In an effort to further our understanding of postural control in Parkinson's disease, we biomechanically evaluated the sit to walk task and its component tasks, sit to stand (STS) and gait initiation (GI) in 12 healthy older adults and 12 persons with Parkinson's disease (PWP). Performance was evaluated utilizing motion capture and two force plates. The major finding of this study was the inability of the PWP to appropriately merge the sequential component tasks (STS and GI) during STW. The PWP rose to nearly full height and had a longer delay between seat-off and gait initiation (P 5 0.003 and P < 0.001, respectively) during STW. Additionally, the PWP moved with slower velocities leading to shorter, slower steps and decreased separation of the center of mass and center of pressure. These observed motor sequencing disturbances may be due to a disease related disability or limitations in proprioception, movement speed, muscular strength, and reduced general mobility.
Sensors, 2020
Evaluating gait stability at slower or faster speeds and self-preferred speeds based on continuous steps may assist in determining the severity of motor symptoms in Parkinson's disease (PD) patients. This study aimed to investigate the gait ability at imposed speed conditions in PD patients during overground walking. Overall, 74 PD patients and 52 age-matched healthy controls were recruited. Levodopa was administered to patients in the PD group, and all participants completed imposed slower, preferred, and faster speed walking tests along a straight 15-m walkway wearing shoe-type inertial measurement units. Reliability of the slower and faster conditions between the estimated and measured speeds indicated excellent agreement for PD patients and controls. PD patients demonstrated higher gait asymmetry (GA) and coefficient of variance (CV) for stride length and stance phase than the controls at slower speeds and higher CVs for phases for single support, double support, and stance. CV of the double support phase could distinguish between PD patients and controls at faster speeds. The GA and CVs of stride length and phase-related variables were associated with motor symptoms in PD patients. Speed conditions should be considered during gait analysis. Gait variability could evaluate the severity of motor symptoms in PD patients.
Fear of falling and postural control in Parkinson's disease
Movement Disorders, 2003
This study investigated the relationship between fear of falling (FOF) and qualitative and quantitative postural control in Parkinson's disease (PD). Fifty-eight nondemented PD patients were studied along with age-matched healthy controls. The degree of FOF was estimated using the Activities-specific Balance Confidence scale. Qualitative postural control was evaluated using a component of the Unified Parkinson Disease Rating Scale. Postural control was quantified, using centre of pressure measures obtained from a force plate, for eight standing balance tests of different challenges. The results showed that FOF was more evident for PD patients when compared with healthy individuals of similar age. Furthermore, FOF was significantly associated with a qualitative estimate of postural control in PD; individuals with PD who had a greater degree of posture impairment reported greater FOF. The results also showed that an estimate of FOF may help to explain quantitative postural instability in PD. FOF, when coupled with a qualitative estimate of postural control, was able to explain a greater amount of variation in quantitative balance performance for five of the eight balance tests. When considered independently, the qualitative measure of postural control, in general, could not well predict quantitative balance performance. The greater degree of FOF and its possible association with altered postural control suggests that FOF should be considered as an important, independent risk factor in the assessment and treatment of postural instability in patients with PD.