Neuromechanical Assessment of Activated vs. Resting Leg Rigidity Using the Pendulum Test Is Associated With a Fall History in People With Parkinson’s Disease

Leg rigidity is associated with frequent falls in people with Parkinson’s disease (PD), suggesting a potential role in functional balance and gait impairments. Changes in the neural state due to secondary tasks, e.g., activation maneuvers, can exacerbate (or “activate”) rigidity, possibly increasing the risk of falls. However, the subjective interpretation and coarse classification of the standard clinical rigidity scale has prohibited the systematic, objective assessment of resting and activated leg rigidity. The pendulum test is an objective diagnostic method that we hypothesized would be sensitive enough to characterize resting and activated leg rigidity. We recorded kinematic data and electromyographic signals from rectus femoris and biceps femoris during the pendulum test in 15 individuals with PD, spanning a range of leg rigidity severity. From the recorded data of leg swing kinematics, we measured biomechanical outcomes including first swing excursion, first extension peak, number and duration of the oscillations, resting angle, relaxation index, maximum and minimum angular velocity. We examined associations between biomechanical outcomes and clinical leg rigidity score. We evaluated the effect of increasing rigidity through activation maneuvers on biomechanical outcomes. Finally, we assessed whether either biomechanical outcomes or changes in outcomes with activation were associated with a fall history. Our results suggest that the biomechanical assessment of the pendulum test can objectively quantify parkinsonian leg rigidity. We found that the presence of high rigidity during clinical exam significantly impacted biomechanical outcomes, i.e., first extension peak, number of oscillations, relaxation index, and maximum angular velocity. No differences in the effect of activation maneuvers between groups with clinically assessed low rigidity were observed, suggesting that activated rigidity may be independent of resting rigidity and should be scored as independent variables. Moreover, we found that fall history was more common among people whose rigidity was increased with a secondary task, as measured by biomechanical outcomes. We conclude that different mechanisms contributing to resting and activated rigidity may play an important yet unexplored functional role in balance impairments. The pendulum test may contribute to a better understanding of fundamental mechanisms underlying motor symptoms in PD, evaluating the efficacy of treatments, and predicting the risk of falls.

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Biomechanical outcomes of the pendulum test characterize individual differences in activated versus resting leg rigidity in people with Parkinson's disease

10.1101/2020.09.07.20188474 ◽

2020 ◽

Author(s):

Giovanni Martino ◽

J Lucas Mckay ◽

Stewart A Factor ◽

Lena H Ting

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Angular Velocity ◽

Objective Assessment ◽

Secondary Tasks ◽

Peak Number ◽

Functional Balance ◽

Pendulum Test ◽

Risk Of Falls ◽

Relaxation Index

Leg rigidity is associated with frequent falls in people with Parkinson's disease (PD), suggesting a potential role in functional balance and gait impairments. Changes in neural state due to secondary tasks, e.g. activation maneuvers, can exacerbate (or 'activate') rigidity, possibly increasing the risk of falls. However, the subjective interpretation and coarse classification of the standard clinical rigidity scale has prohibited the systematic, objective assessment of resting and activated leg rigidity. The pendulum test is an objective diagnostic method that we hypothesized would be sensitive enough to characterize resting and activated leg rigidity. We recorded kinematic data during the pendulum test in 15 individuals with PD, spanning a range of leg rigidity severity (slight to severe). From the recorded data of leg swing kinematics we measured biomechanical outcomes including first swing excursion, first extension peak, number and duration of the oscillations, resting angle, relaxation index, maximum and minimum angular velocity. We examined associations between biomechanical outcomes and clinical leg rigidity score. We evaluated the effect of increasing rigidity through activation maneuvers on biomechanical outcomes. Finally, we assessed whether either biomechanical outcomes or changes in outcomes with activation were associated with fall history. Our results suggest that the biomechanical assessment of the pendulum test can objectively quantify leg rigidity among people with PD. We found that the presence of marked rigidity during clinical exam significantly impacted biomechanical outcomes, i.e. first extension peak, number of oscillations, relaxation index and maximum angular velocity. No differences in the effect of activation maneuvers between groups with clinically assessed moderate and marked rigidity were observed, suggesting that activated rigidity may be independent of resting rigidity and should be scored as independent variables. Moreover, we found that fall history was more common among people whose rigidity was increased with a secondary task, as measured by biomechanical outcomes. We conclude that different mechanisms contributing to resting and activated rigidity may play an important yet unexplored functional role in balance impairments. The pendulum test may contribute to a better understanding of fundamental mechanisms underlying motor symptoms in PD, evaluating the efficacy of treatments, and predicting the risk of falls.

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Relationship between Muscular Activity and Postural Control Changes after Proprioceptive Focal Stimulation (Equistasi®) in Middle-Moderate Parkinson’s Disease Patients: An Explorative Study

Sensors ◽

10.3390/s21020560 ◽

2021 ◽

Vol 21 (2) ◽

pp. 560

Author(s):

Fabiola Spolaor ◽

Marco Romanato ◽

Guiotto Annamaria ◽

Antonella Peppe ◽

Leila Bakdounes ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Postural Control ◽

Quantitative Estimation ◽

Force Plate ◽

Muscular Activity ◽

Rectus Femoris ◽

Biceps Femoris ◽

Eyes Open ◽

Romberg Test

The aim of this study was to investigate the effects of Equistasi®, a wearable device, on the relationship between muscular activity and postural control changes in a sample of 25 Parkinson’s disease (PD) subjects. Gait analysis was carried out through a six-cameras stereophotogrammetric system synchronized with two force plates, an eight-channel surface electromyographic system, recording the activity of four muscles bilaterally: Rectus femoris, tibialis anterior (TA), biceps femoris, and gastrocnemius lateralis (GL). The peak of the envelope (PoE) and its occurrence within the gait cycle (position of the peak of the envelope, PPoE) were calculated. Frequency-domain posturographic parameters were extracted while standing still on a force plate in eyes open and closed conditions for 60 s. After the treatment with Equistasi®, the mid-low (0.5–0.75) Hz and mid-high (0.75–1 Hz) components associated with the vestibular and somatosensory systems, PoE and PPoE, displayed a shift toward the values registered on the controls. Furthermore, a correlation was found between changes in proprioception (power spectrum frequencies during the Romberg Test) and the activity of GL, BF (PoE), and TA (PPoE). Results of this study could provide a quantitative estimation of the effects of a neurorehabilitation device on the peripheral and central nervous system in PD.

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Thalamic morphology predicts the onset of freezing of gait in Parkinson’s disease

npj Parkinson s Disease ◽

10.1038/s41531-021-00163-0 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Nicholas D’Cruz ◽

Griet Vervoort ◽

Sima Chalavi ◽

Bauke W. Dijkstra ◽

Moran Gilat ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Resting State ◽

Freezing Of Gait ◽

Study Entry ◽

Resting State Functional Connectivity ◽

Behavioral Correlates ◽

Local Volume ◽

Linear Evolution ◽

Risk Of Falls

AbstractThe onset of freezing of gait (FOG) in Parkinson’s disease (PD) is a critical milestone, marked by a higher risk of falls and reduced quality of life. FOG is associated with alterations in subcortical neural circuits, yet no study has assessed whether subcortical morphology can predict the onset of clinical FOG. In this prospective multimodal neuroimaging cohort study, we performed vertex-based analysis of grey matter morphology in fifty-seven individuals with PD at study entry and two years later. We also explored the behavioral correlates and resting-state functional connectivity related to these local volume differences. At study entry, we found that freezers (N = 12) and persons who developed FOG during the course of the study (converters) (N = 9) showed local inflations in bilateral thalamus in contrast to persons who did not (non-converters) (N = 36). Longitudinally, converters (N = 7) also showed local inflation in the left thalamus, as compared to non-converters (N = 36). A model including sex, daily levodopa equivalent dose, and local thalamic inflation predicted conversion with good accuracy (AUC: 0.87, sensitivity: 88.9%, specificity: 77.8%). Exploratory analyses showed that local thalamic inflations were associated with larger medial thalamic sub-nuclei volumes and better cognitive performance. Resting-state analyses further revealed that converters had stronger thalamo-cortical coupling with limbic and cognitive regions pre-conversion, with a marked reduction in coupling over the two years. Finally, validation using the PPMI cohort suggested FOG-specific non-linear evolution of thalamic local volume. These findings provide markers of, and deeper insights into conversion to FOG, which may foster earlier intervention and better mobility for persons with PD.

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A Wearable System to Objectify Assessment of Motor Tasks for Supporting Parkinson’s Disease Diagnosis

Sensors ◽

10.3390/s20092630 ◽

2020 ◽

Vol 20 (9) ◽

pp. 2630 ◽

Cited By ~ 2

Author(s):

Erika Rovini ◽

Carlo Maremmani ◽

Filippo Cavallo

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Objective Assessment ◽

Disease Diagnosis ◽

Support Vector ◽

Motor Tasks ◽

Wearable System ◽

Support Tool ◽

Average Accuracy ◽

Open Issue

Objective assessment of the motor evaluation test for Parkinson’s disease (PD) diagnosis is an open issue both for clinical and technical experts since it could improve current clinical practice with benefits both for patients and healthcare systems. In this work, a wearable system composed of four inertial devices (two SensHand and two SensFoot), and related processing algorithms for extracting parameters from limbs motion was tested on 40 healthy subjects and 40 PD patients. Seventy-eight and 96 kinematic parameters were measured from lower and upper limbs, respectively. Statistical and correlation analysis allowed to define four datasets that were used to train and test five supervised learning classifiers. Excellent discrimination between the two groups was obtained with all the classifiers (average accuracy ranging from 0.936 to 0.960) and all the datasets (average accuracy ranging from 0.953 to 0.966), over three conditions that included parameters derived from lower, upper or all limbs. The best performances (accuracy = 1.00) were obtained when classifying all the limbs with linear support vector machine (SVM) or gaussian SVM. Even if further studies should be done, the current results are strongly promising to improve this system as a support tool for clinicians in objectifying PD diagnosis and monitoring.

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Long-term risk of falls in an incident Parkinson’s disease cohort: the Norwegian ParkWest study

Journal of Neurology ◽

10.1007/s00415-016-8365-z ◽

2016 ◽

Vol 264 (2) ◽

pp. 364-372 ◽

Cited By ~ 12

Author(s):

Ylva Hivand Hiorth ◽

Guido Alves ◽

Jan Petter Larsen ◽

Jörn Schulz ◽

Ole-Bjørn Tysnes ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Risk Of Falls

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Quantification of Arm Swing during Walking in Healthy Adults and Parkinson’s Disease Patients: Wearable Sensor-Based Algorithm Development and Validation

Sensors ◽

10.3390/s20205963 ◽

2020 ◽

Vol 20 (20) ◽

pp. 5963 ◽

Cited By ~ 1

Author(s):

Elke Warmerdam ◽

Robbin Romijnders ◽

Julius Welzel ◽

Clint Hansen ◽

Gerhard Schmidt ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Angular Velocity ◽

Wearable Sensors ◽

Healthy Adults ◽

Wearable Sensor ◽

Arm Swing ◽

Optical Motion ◽

Optical Motion Capture ◽

Development And Validation

Neurological pathologies can alter the swinging movement of the arms during walking. The quantification of arm swings has therefore a high clinical relevance. This study developed and validated a wearable sensor-based arm swing algorithm for healthy adults and patients with Parkinson’s disease (PwP). Arm swings of 15 healthy adults and 13 PwP were evaluated (i) with wearable sensors on each wrist while walking on a treadmill, and (ii) with reflective markers for optical motion capture fixed on top of the respective sensor for validation purposes. The gyroscope data from the wearable sensors were used to calculate several arm swing parameters, including amplitude and peak angular velocity. Arm swing amplitude and peak angular velocity were extracted with systematic errors ranging from 0.1 to 0.5° and from −0.3 to 0.3°/s, respectively. These extracted parameters were significantly different between healthy adults and PwP as expected based on the literature. An accurate algorithm was developed that can be used in both clinical and daily-living situations. This algorithm provides the basis for the use of wearable sensor-extracted arm swing parameters in healthy adults and patients with movement disorders such as Parkinson’s disease.

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Parkinson’s Disease and Symptomatic Osteoarthritis Are Independent Risk Factors of Falls in the Elderly

Clinical Medicine Insights Arthritis and Musculoskeletal Disorders ◽

10.1177/1179544119884936 ◽

2019 ◽

Vol 12 ◽

pp. 117954411988493 ◽

Cited By ~ 2

Author(s):

Anneli Teder-Braschinsky ◽

Aare Märtson ◽

Marika Rosenthal ◽

Pille Taba

Keyword(s):

Risk Factors ◽

Parkinson’S Disease ◽

Parkinson's Disease ◽

Knee Osteoarthritis ◽

The Elderly ◽

Control Group ◽

Increased Risk ◽

Symptomatic Knee ◽

Risk Of Falls ◽

Risk Factors For Falls

Objectives: Deteriorating functionality and loss of mobility, resulting from Parkinson’s disease, may be worsened by osteoarthritis, which is the most common form of joint disease causing pain and functional impairment. We assessed the association between symptomatic hip or knee osteoarthritis, falls, and the ability to walk among patients with Parkinson’s disease compared to a control group. Methods: A total of 136 patients with Parkinson’s disease in Southern Estonia and 142 controls with an average age of 76.8 and 76.3 years, respectively, were enrolled in a retrospective case-control study. Information on falls and related fractures during the previous year was collected from the patients with Parkinson’s disease and controls. Covariates included gender, age, mobility, duration of Parkinson’s disease, and fractures. Results: Patients with Parkinson’s disease were at an increased risk of falls compared to the control group, and for the higher risk of fractures. Symptomatic knee or hip osteoarthritis was a significant independent predictor of falls in both patients with Parkinson’s disease and controls. The higher risk for fractures during the previous year was demonstrated in symptomatic osteoarthritis. Risk factors for falls included also female gender, use of sleep pills, and the inability to walk 500 m. Conclusions: Symptomatic hip and knee osteoarthritis are risk factors for falls and related fractures among the elderly population with and without Parkinson’s disease. The inability to walk 500 m could be used as a simple predictive factor for the increased risk of falls among elderly populations.

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Risk of Falls in Parkinson’s Disease: A Cross-Sectional Study of 160 Patients

Parkinson s Disease ◽

10.1155/2012/362572 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 19

Author(s):

Ana Contreras ◽

Francisco Grandas

Keyword(s):

Risk Factors ◽

Parkinson’S Disease ◽

Parkinson's Disease ◽

Disease Risk ◽

Cross Sectional Study ◽

Operating Characteristics ◽

Balance Test ◽

Cross Sectional ◽

Risk Of Falls ◽

Risk Factors For Falling

Falls are a major source of disability in Parkinson’s disease. Risk factors for falling in Parkinson’s disease remain unclear. To determine the relevant risk factors for falling in Parkinson’s disease, we screened 160 consecutive patients with Parkinson’s disease for falls and assessed 40 variables. A comparison between fallers and nonfallers was performed using statistical univariate analyses, followed by bivariate and multivariate logistic regression, receiver-operating characteristics analysis, and Kaplan-Meier curves. 38.8% of patients experienced falls since the onset of Parkinson’s disease (recurrent in 67%). Tinetti Balance score and Hoehn and Yahr staging were the best independent variables associated with falls. The Tinetti Balance test predicted falls with 71% sensitivity and 79% specificity and Hoehn and Yahr staging with 77% sensitivity and 71% specificity. The risk of falls increased exponentially with age, especially from 70 years onward. Patients aged >70 years at the onset of Parkinson’s disease experienced falls significantly earlier than younger patients.

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