Gait In Subjects Research Articles

Arthroscopic removal of the fragmented medial coronoid process in dogs - Evaluation of treatment results with special reference to postoperative computed tomography and residual particles

The aim of this study was to assess the treatment success of dogs with medial coronoid disease (here: Fragmented Coronoid Process [FCP]) following arthroscopically performed subtotal coronoidectomy by the use of subjective and objective gait analysis and the evaluation of osteoarthritis progression in addition to their correlation with the findings from postoperative computed tomography. In particular, the clinical relevance of residual particles remaining postoperatively was to be evaluated. Thirty elbows from 24 dogs of different breeds were examined clinically, orthopedically, using gait analysis as well as radiographically at least 6 months after unilateral or bilateral subtotal coronoidectomy. The results were compared with the preoperative findings of the corresponding examinations and postoperative computed tomography. 79.2% (19/24) of the patients improved by at least one degree of lameness in the orthopedic examination, 66.7% (16/24) were free of lameness. 60% (18/30 joints) showed an increase in the degree of arthrosis. Postoperative computed tomography revealed small residual bone particles (<1 mm) in the joint space or soft tissue in 56.7% (17/30) of the joints. No significant association was evident between residual lameness and residual particles remaining within the joint postoperatively. An association between persistent lameness and progression of arthrosis was also not be demonstrable. No evidence was apparent supporting a link between residues of small bone particles after arthroscopic subtotal coronoidectomy and postoperative lameness. The progression of osteoarthritis could not be interrupted despite the surgical intervention. When small residual particles (<1 mm) remain after subtotal coronoidectomy, these do not appear to have any influence on the clinical outcome.

Dynamical systems theory applied to short walking trials

Human walking is an extremely complex neuromuscular activity whose simplicity disappears when an attempt is made to provide a quantitative description of the process. The dynamical systems theory provides a framework for analyzing the stability and chaotic nature of dynamical systems, employing Floquet multipliers (FM) and long and short-term Lyapunov exponents (LE), respectively. This report compares FM and LE from three methods: method A (false nearest neighbors and numerical approximation), method B (false nearest neighbors and semi-analytical technique) and method C (singular value decomposition and semi-analytical technique). Data from 33 healthy older adults with no history of falls were used to explain the dynamic system. A surrogate center of mass trajectory was calculated for the analysis of sway in the transverse plane. Results revealed methodological differences in LE and FM calculations with semi-analytical solutions providing closer approximations to observed gait behavior. The long-term LE from Methods A and B were similar, but other LE pairings differed. Method A’s short-term LE indicated chaotic gaits for all subjects, while long-term LE from Methods A and B indicated chaos for half the subjects. Method C showed non-chaotic gait for most subjects. Method B’s FM indicated over 30% of subjects had unstable gait. Method C yielded values of LE and FM that most closely matched the subjects’ gait patterns. This study offers a methodological foundation for gait analysis using short time-series data, facilitating deeper insights into both stability and chaos within gait dynamics.

Dementia with Lewy bodies and gait neural basis: a cross-sectional study

BackgroundDementia with Lewy Bodies (DLB) is responsible for cognitive-behavioural disorders but also for gait disorders. The latter are thought to be related to parkinsonism, but the neural bases of these disorders are not well known, especially in the early stages. The aim of this study was to investigate by volumetric Magnetic Resonance Imaging the neuronal basis of gait disorders in DLB patients, compared to Healthy Elderly Controls and Alzheimer’s Disease patients.MethodsClinical examination with motor assessment including 10-meter walking speed, one-leg balance and Timed Up and Go test, a comprehensive neuropsychological evaluation and 3D brain Magnetic Resonance Imaging were performed on 84 DLB patients, 39 Alzheimer’s Disease patients and 22 Healthy Elderly Controls. We used Statistical Parametric Mapping 12 to perform a one-sample t-test to investigate the correlation between each gait score and gray matter volume (P ≤ 0.05 corrected for family-wise error).ResultsWe found a correlation for DLB patients between walking speed and gray matter decrease (P < 0.05, corrected for family-wise error) in caudate nuclei, anterior cingulate cortex, mid-cingulate cortex, hippocampi, supplementary motor area, right cerebellar cortex and left parietal operculum. We found no correlation with Timed Up and Go test and one-leg balance.ConclusionGait disorders are underpinned by certain classical regions such as the cerebellum and the supplementary motor area. Our results suggest there may be a motivational and emotional component of voluntary gait in DLB subjects, underpinned by the cingulate cortex, a spatial orientation component, underpinned by hippocampi and suggest the involvement of brain processing speed and parkinsonism, underpinned by the caudate nuclei.Trial registrationThe study protocol has been registered on ClinicalTrials.gov. (NCT01876459) on June 12, 2013.

Prefrontal Cortex Oxygenation During Exercise in Older Adults with Motoric Cognitive Risk Syndrome.

Motoric cognitive risk syndrome (MCR) is a pre-dementia syndrome characterized by subjective memory complaints and gait impairments that may be related to lower prefrontal cortex (PFC) function. Acute bouts of aerobic exercise are shown to improve PFC function, however, the acute effects of exercise on PFC oxygenation have not yet been examined in MCR. This study aims to characterize the PFC oxygenation responses during acute exercise in older adults with MCR. Nineteen older adults with MCR performed a submaximal cycling exercise protocol. Functional near-infrared spectroscopy (fNIRS) is used to measure concentrations of oxygenated (OxyHb) and deoxygenated (DeoxyHb) hemoglobin from the PFC. There is a trend for increased OxyHb concentrations and decreased DeooxyHb concentrations during exercise. Exercise also induced significant increases in ratings of perceived exertion (RPEs) and heart rate. A significant, positive correlation between PFC OxyHb and RPEs during the cycling exercise are also observed. The findings reveal that PFC oxygenation increases during exercise in an intensity-dependent manner and the subjective perception of exertion is associated with the magnitude of PFC oxygenation. These results suggest that moderate-intensity cycling exercise may have beneficial effects on increasing cerebral blood flow in the PFC of older adults with MCR.

Visual scale to document acute dizziness in the hospital.

Managing acute vertigo/dizziness for inpatients requires valid communication between the various healthcare professionals that triage such life-threatening presentations, yet there are no current scaling methods for managing such acute vertigo symptoms for inpatients. To describe the development and validation of the Krems Acute Vertigo/Dizziness Scale (KAVEDIS), a new instrument for tracking subjective symptoms (vertigo, dizziness) and gait impairment across four unique vestibular diagnoses (Menière's disease, benign paroxysmal positional vertigo, peripheral vestibular hypofunction, and vestibular migraine) over a one-year period after inpatient hospital admission. Retrospective data collection study from KAVEDIS scale and chart documentation. The KAVEDIS scale can significantly distinguish scores from admission to discharge in three of four vestibular diagnoses. The documented course of subjective vestibular symptoms and gait disturbances were correlated in all four groups. We suggest that KAVEDIS documentation among inpatients admitted with acute vertigo/dizziness may improve communication between the various intervening clinicians and help to raise concern in cases of symptomprogression.

Short-term outcomes of 43 dogs treated with arthroscopic suturing for meniscal tears associated with cranial cruciate ligament disease.

To describe short-term outcomes and complications in dogs receiving meniscal suturing and concurrent tibial plateau leveling osteotomy (TPLO) with or without augmentation with an extracapsular suture. Retrospective case series. Forty-three client-owned dogs submitted for cruciate ligament disease. Dogs were included if meniscal suturing was performed during or after a TPLO procedure. Criteria included an unstable medial meniscus without evidence of a tear, a caudal vertical longitudinal tear with or without displacement, or if a bucket-handle tear was debrided and the remaining rim was unstable. Stifle stabilization was performed by either a standard TPLO or an augmented TPLO (TPLO + internal brace [IB]). Outcome measures included physical examination findings, radiographs, subjective gait examination, Liverpool Osteoarthritis in Dogs (LOAD) scores, and second-look arthroscopy. Forty-four meniscal repairs were performed in 43 dogs. Five types of meniscal tears were treated employing eight suture materials. Complications were documented in 15 cases (34%). The stabilization technique had a significant impact on the outcome (p = .049): TPLO + IB had a 93.3% success rate and the success rate was 71.4% in the TPLO-only group. Five types of meniscal pathology were addressed successfully in the study, indicating that currently accepted criteria for meniscal suturing in dogs may be overly conservative. The majority of complications were not related to the meniscal suturing itself and did not compromise the outcome. The stifle stabilization technique had an impact on outcome. The authors found arthroscopic meniscal suturing to be practical and successful in this patient population. Postoperative stifle stability had an impact on successful treatment.

Inertial Measuring System to Evaluate Gait Parameters and Dynamic Alignments for Lower-Limb Amputation Subjects.

The study aims to construct an inertial measuring system for the application of amputee subjects wearing a prosthesis. A new computation scheme to process inertial data by installing seven wireless inertial sensors on the lower limbs was implemented and validated by comparing it with an optical motion capture system. We applied this system to amputees to verify its performance for gait analysis. The gait parameters are evaluated to objectively assess the amputees' prosthesis-wearing status. The Madgwick algorithm was used in the study to correct the angular velocity deviation using acceleration data and convert it to quaternion. Further, the zero-velocity update method was applied to reconstruct patients' walking trajectories. The combination of computed walking trajectory with pelvic and lower limb joint motion enables sketching the details of motion via a stickman that helps visualize and animate the walk and gait of a test subject. Five participants with above-knee (n = 2) and below-knee (n = 3) amputations were recruited for gait analysis. Kinematic parameters were evaluated during a walking test to assess joint alignment and overall gait characteristics. Our findings support the feasibility of employing simple algorithms to achieve accurate and precise joint angle estimation and gait parameters based on wireless inertial sensor data.

Association between subjective physical function and occurrence of new fractures in older adults: A retrospective cohort study.

The Late-Stage Elderly Questionnaire has been incorporated into health assessments for older adults in Japan, encompassing three self-administered questions on subjective physical function: subjective gait speed decline, recent fall history, and exercise habits. Nevertheless, its efficacy in predicting new fracture occurrences remains uncertain. This retrospective cohort study utilized Japan's DeSC database, a large commercially available claims database. Participants were older adults aged ≥75 years and provided complete responses to the Late-Stage Elderly Questionnaire at health check-ups. We performed two Cox regression analyses for new fractures based on the responses to the three questions (Model 1) and on age, sex, and responses to the three questions (Model 2). The predictive abilities of the 1-year occurrence of new fractures were compared between the two models. Of 11 683 eligible older adults, 927 (7.93%) experienced new fractures. Model 1 revealed significant associations between new fractures and subjective gait speed decline (hazard ratio [HR], 1.63; 95% confidence interval [CI], 1.40-1.89), recent fall history (HR, 2.03; 95% CI, 1.77-2.33), and absence of exercise habits (HR, 1.29; 95% CI, 1.13-1.47). Model 2 demonstrated superior predictive ability (area under the curve, 0.677; 95% CI, 0.659-0.695) compared with Model 1 (area under the curve, 0.633; 95% CI, 0.614-0.652), with a net reclassification improvement of 0.383 (95% CI, 0.317-0.449). Three subjective physical well-being factors were significantly associated with new fracture development in older adults. These results suggest that the three-question assessment may be a valuable screening tool for identifying new fractures. Geriatr Gerontol Int 2024; 24: 337-343.

Exploring Upper Limb Kinematics in Limited Vision Conditions: Preliminary Insights from 3D Motion Analysis and IMU Data

This study examined upper limb kinematics under simulated visually impaired conditions. By investigating how upper limb movements adapt in these circumstances, we aimed to gain insights that may prove valuable for both healthy populations and those with clinical conditions. Data, including 3D marker-based motion capture and accelerometer readings, were collected from seven healthy volunteers walking on a treadmill at 1.5 m/s under two conditions: without glasses (NG) and with stroboscopic glasses (G). Each walking condition lasted 2 minutes, and two 10-second recordings were analyzed from the midpoint of each session. Contrary to our hypothesis, simulated visual impairment with stroboscopic eyewear at 6Hz did not statistically affect upper limb kinematics, specifically in terms of wrist acceleration and hand distance in the frontal plane. Future research should explore varied visual impairment conditions, extend task durations, and investigate the relationship between subjective gait difficulties and biomechanical data.

Speed-dependent modulations of asymmetric center of body mass trajectory in the gait of above-knee amputee subjects.

How to achieve stable locomotion while overcoming various instabilities is an ongoing research topic. One essential factor for achieving a stable gait is controlling the center of body mass (CoM). The CoM yields more instability in the mediolateral direction. Examining speed-dependent modulations of the CoM trajectories in the frontal plane can provide insight into control policies for achieving stable locomotion. Although these modulations have been studied while assuming symmetric CoM trajectories, this assumption is generally incorrect. For example, amputee subjects demonstrate asymmetric CoM trajectories. Here, we investigated speed-dependent modulations of asymmetric CoM trajectories in above-knee amputee subjects using Fourier series expansion. Despite the asymmetric CoM trajectories in amputee subjects, the framework of Fourier series expansion clarified that amputee subjects showed the same speed-dependent modulations as non-amputee subjects whose CoM trajectories were symmetric. Specifically, CoM trajectories became narrower in the mediolateral direction and broader in the superoinferior direction as walking speed increased. The speed-dependent modulations of CoM trajectories had a functional role in improving dynamic stability, and faster walking speeds provided greater dynamic stability on both prosthetic and non-prosthetic sides. Although the asymmetry of foot contact duration and CoM trajectory decreased as walking speed increased, step width and the asymmetry of dynamic stability between prosthetic and non-prosthetic sides remained constant across the walking speed, which corresponded to the predictions by our framework. These findings could offer a better strategy for achieving stable walking for amputee subjects.

Robotic exoskeleton embodiment in post-stroke hemiparetic patients: an experimental study about the integration of the assistance provided by the REFLEX knee exoskeleton

Hemiparetic gait is the most common motor-disorder after stroke and, in spite of rehabilitation efforts, it is persistent in 50% of community dwelling stroke-survivors. Robotic exoskeletons have been proposed as assistive devices to support impaired joints. An example of these devices is the REFLEX knee exoskeleton, which assists the gait of hemiparetic subjects and whose action seems to be properly embodied by stroke survivors, who were able to adapt the motion of their non-assisted limbs and, therefore, reduce their compensation mechanisms. This paper presents an experimental validation carried out to deepen into the effects of REFLEX’s assistance in hemiparetic subjects. Special attention was paid to the effect produced in the muscular activity as a metric to evaluate the embodiment of this technology. Significant differences were obtained at the subject level due to the assistance; however, the high dispersion of the measured outcomes avoided extracting global effects at the group level. These results highlight the need of individually tailoring the action of the robot to the individual needs of each patient to maximize the beneficial outcomes. Extra research effort should be done to elucidate the neural mechanisms involved in the embodiment of external devices by stroke survivors.

A Reference Data Set for the Study of Healthy Subject Gait with Inertial Measurements Units

A Reference Data Set for the Study of Healthy Subject Gait with Inertial Measurements Units

FC45: Clinical profiles for motoric cognitive risk syndrome in rural-dwelling older adults: the MIND-China study

Objective:Motoric cognitive risk syndrome (MCR), which is defined as a pre-dementia syndrome characterized by subjective cognitive complaints and slow gait in older individuals free of dementia and mobility disability, has been associated with increased risks of dementia, functional dependence, and mortality. The aims of this study were to describe the prevalence and distribution of MCR and to explore the clinical profiles associated with MCR in rural-dwelling older adults.Methods:The population-based cross-sectional study included 5,021 dementia- and disability-free participants (age ≥60 years; 56.48% women) in the baseline assessments (March-September 2018) of the Multimodal Interventions to delay Dementia and disability in rural China (MIND-China). The MCR syndrome was diagnosed when the participants had subjective memory complaints and gait speed ≥1 standard deviation (SD) below the age- (&lt;75 and ≥75 years) and sex-specific means. We estimated the age- and sex-specific prevalence of MCR. We used logistic regression models to examine lifestyle and clinical factors associated with MCR while controlling for age, sex, and education.Results:The overall prevalence of MCR syndrome was 13.58%, with the prevalence being 11.53% in males and 15.16% in females (P&lt;0.001). The prevalence of MCR was increased with age, from 10.43% in people aged 60-69 years and 15.97% in those aged 70-79 years to 21.71% among those aged ≥80 years. The demographic-adjusted odds ratio (95% confidence interval) of MCR was 1.30 (1.08-1.57) for being overweight (body mass index 24-27.9 vs. &lt;24 kg/m2), 1.65 (1.32-2.05) for having obesity (≥28 kg/m2), 1.74 (1.41-2.15) for diabetes, 1.44 (1.20-1.73) for dyslipidemia, 1.59 (1.32-1.91) for having coronary heart disease, 2.17 (1.78-2.65) for having stroke history, 1.52 (1.24-1.86) for having osteoarthritis, and 3.40 (2.70-4.28) for having depressive symptoms. Ever (vs. never) smoking and alcohol consumption were related to odds ratio of 0.65 (0.48-0.86) and 0.71 (0.55-0.91), respectively, for MCR syndrome.Conclusion:The MCR syndrome affects nearly 1 in 7 Chinese rural older adults, and the MCR prevalence appears to be higher in women than in men. Cardiometabolic risk factors (e.g., overweight/obesity, diabetes, and dyslipidemia), osteoarthritis, coronary heart disease, stroke, and depressive symptoms were associated with increased likelihoods of the MCR syndrome.

Stretching and Eccentric Exercises Normalize Gait Parameters in Gastrocnemius Tightness Subjects

Background: Isolated gastrocnemius tightness (IGT) is a prevalent condition linked to various foot pathologies. In a previous quantitative gait analysis study, we identified an increase in knee flexion during the midstance phase in IGT patients compared with controls. Although stretching and eccentric exercises (the Stanish protocol) are commonly used for IGT management, their impact on gait parameters remains poorly understood. This study aimed to assess the influence of a Stanish protocol on gait parameters in bilateral IGT subjects. Methods: We enrolled 10 asymptomatic bilateral IGT subjects and 10 controls. Quantitative gait analysis and dynamic baropodometry were carried out on each subject. A Stanish protocol was applied for 4 weeks (five sessions/week) by the IGT group, followed by a similar gait analysis. The ankle and knee range of motion and foot pressure distribution were assessed during the midstance phase of the gait. Results: An increase in knee flexion was initially present in the IGT group compared with controls (8.9 +/− 4.6 vs. 3.4 +/− 2.3 degrees, p &lt; 0.001). There was no difference in the ankle range of motion and foot pressures between the groups at that time. Significant reductions in knee flexion during gait were observed in the IGT subjects after the Stanish protocol (8.9 +/− 4.6 to 3.7 +/− 2.3 degrees, p &lt; 0.001) with a normalization of this parameter (3.4 +/− 2.3 in controls vs. 3.7 +/− 2.3 degrees in IGT, p = 0.72). There was no change in ankle range of motion and foot pressure after the Stanish protocol. Conclusions: Our findings support the effectiveness of the Stanish protocol in reducing knee flexion and normalizing gait in IGT subjects. This protocol not only offers a noninvasive approach for IGT-related issues management but could also enable prophylactic care in asymptomatic cases.

Dual decline in subjective gait speed and domain-specific cognition is associated with higher risk of incident dementia in older Japanese adults: A 15-year age-specific cohort study

ObjectivesDual decline in gait speed and cognition has been found to have higher dementia risk than no decline or pure decline. However, evidence from the Asian population is lacking. Therefore, we aimed to investigate the association of dual decline from age 65 to 70 years with late-life dementia in older Japanese adults with different personal characteristics. MethodsData were collected from an age-specific cohort study conducted in 482 Japanese 65-year-old adults. We investigated participant demographics, medical histories, lifestyles, subjective gait speed, and cognition at both 64/65 and 70/71 years old, and confirmed dementia until age of 85 years. Cox proportion hazard models were used to estimate the risk of dementia, with adjustments for covariates, and death was treated as a competing risk. ResultsAfter a mean follow-up period of 12.5-years, 111 participants developed dementia. Older adults with dual decline are more likely to have hyperlipidemia, diabetes, and smoking habits. And we found that dual decline in gait speed and domain-specific cognition was associated with a higher risk of dementia compared with no decline in most cognitive tests, with the highest risk observed for gait speed combined with memory (sub-distribution hazard ratio:3.89, 95 %, confidence intervals: [1.68–9.01]). However, significant differences only existed in men after stratification by sex. ConclusionsA dual decline in subjective gait speed and cognition may serve as a robust predictor of dementia over a decade prior to its onset, particularly in men. These findings highlighted the importance of screening for dual decline at an early age.

Effects of supervised structured exercise program on postural control and gait in subjects with type-2 diabetes

Abstract Type-2 diabetes mellitus, one of the most common metabolic diseases in the world, is brought on by the interaction of two critical factors: reduced insulin secretion by pancreatic beta-cells and impaired insulin sensitivity of tissues. The objective of the study was to see the effects of supervised structured exercise program on postural control and gait in subjects with type-2 diabetes. The study recruited 44 type-2 diabetic subjects who were randomly divided into two groups: experimental group (n = 22) and control group (n = 22). Functional reach test and dynamic gait index were used as outcome measures for pre- and postevaluations of postural control and gait, respectively. The study identified a mean improvement of 2.54 ± 11.31 and 3 ± 14.31 in the experimental and control groups, respectively. Both groups showed significant improvements in postural control and gait after the intervention (P &lt; 0.05). The level of improvement in the experimental group was significantly higher in improving postural control compared with the control group (P &lt; 0.05). The results of the study demonstrated that structured exercise program is effective in improving postural control and gait in subjects with type-2 diabetes.

DeepaMed: Deep learning-based medication adherence of Parkinson's disease using smartphone gait analysis

ObjectivesParkinson's disease (PD) is a neurodegenerative chronic disorder with multiple motor and non-motor symptoms. As PD has no ultimate cure, physicians aim to delay PD complications, especially those that degrade the patient's quality of life such as motor symptoms and dyskinesia. Patients' lack of adherence to prescribed medication is a major challenge for physicians, especially for patients suffering from chronic conditions. The Centers for Disease Control and Prevention (CDC) estimates that medication non-adherence causes 30 to 50 percent of chronic disease treatment failures and 125,000 deaths per year in the USA (U.S. Foods and Drugs Administration (FDA) “Why You Need to Take Your Medications as Prescribed or Instructed” https://www.fda.gov/drugs/special-features/why-you-need-take-your-medications-prescribed-or-instructed. June 2021). In PD patients particularly, adherence varies between 10% and 67% (Straka et al., 2019Straka, Igor, et al. "Adherence to pharmacotherapy in patients with Parkinson's disease taking three and more daily doses of medication." Frontiers in neurology 10 (2019): 799). ObjectiveThe goal of this work is to remotely determine whether PD patients have taken their medication, by analyzing gait data gathered from their smartphone sensors. Using this approach, physicians can track the level of medication adherence of their PD patients. MethodologyUsing data from the mPower study (Bot et al., 2016), we selected 152 PD patients who recorded at least 3 walks before and 3 after taking medications and 304 healthy controls (HC) who recorded 3 walks at minimum. We extracted each subject's gait cycle from their accelerometer and gyroscope sensors data. The sensor data corresponding to gait cycles were fed to DeePaMed; a multilayer Conventional Neural Network (CNN), crafted for patches of gait strides. DeePaMed classified 30 s of a walk as either PD patient “On” vs. “Off” medication, or if the gait data belongs to an HC. ResultsOur DeePaMed model was able to discriminate PD patients on-vs off-medication and baseline HC walk with an accuracy of 98.2%. The accuracy of our CNN model surpassed that of traditional Machine Learning methods by over 17%. We also found that our model performed best with inputs containing a minimum of 10 full gait strides. ConclusionMedication non-adherence can be accurately predicted using smartphone sensing of the motor symptoms of PD, suggesting that PD patients’ medication response and non-adherence can be monitored remotely via smartphone-based measures.

Subject-specific tribo-contact conditions in total knee replacements: a simulation framework across scales.

Fundamental knowledge about invivo kinematics and contact conditions at the articulating interfaces of total knee replacements are essential for predicting and optimizing their behavior and durability. However, the prevailing motions and contact stresses in total knee replacements cannot be precisely determined using conventional invivo measurement methods. Insilico modeling, in turn, allows for a prediction of the loads, velocities, deformations, stress, and lubrication conditions across the scales during gait. Within the scope of this paper, we therefore combine musculoskeletal modeling with tribo-contact modeling. In the first step, we compute contact forces and sliding velocities by means of inverse dynamics approach and force-dependent kinematic solver based upon experimental gait data, revealing contact forces during healthy/physiological gait of young subjects. In a second step, the derived data are employed as input data for an elastohydrodynamic model based upon the finite element method full-system approach taking into account elastic deformation, the synovial fluid's hydrodynamics as well as mixed lubrication to predict and discuss the subject-specific pressure and lubrication conditions.

Quasi-passive lower limbs exosuit: an in-depth assessment of fatigue, kinematic and muscular patterns while comparing assistive strategies on an expert subject's gait analysis.

Wearable robots are becoming a valuable solution that helps injured, and elderly people regain mobility and improve clinical outcomes by speeding up the rehabilitation process. The XoSoft exosuit identified several benefits, including improvement of assistance, usability, and acceptance with a soft, modular, bio-mimetic, and quasi-passive exoskeleton. This study compares two assistive configurations: (i) a bilateral hip flexion (HA, hips-assistance) and (ii) a bilateral hip flexion combined with ankle plantarflexion (HAA, hips-ankles-assistance) with the main goal of evaluating compensatory actions and synergetic effects generated by the human- exoskeleton interaction. A complete description of this complex interaction scenario with this actuated exosuit is evaluated during a treadmill walking task, using several indices to quantify the human-robot interaction in terms of muscular activation and fatigue, metabolic expenditure, and kinematic motion patterns. Evidence shows that the HAA biomimetic controller is synergetic with the musculature and performs better concerning the other control strategy. The experimentation demonstrated a metabolic expenditure reduction of 8% of Metabolic Equivalent of Task (MET), effective assistance of the muscular activation of 12.5%, a decrease of the muscular fatigue of 0.6% of the mean frequency, and a significant reduction of the compensatory actions, as discussed in this work. Compensatory effects are present in both assistive configurations, but the HAA modality provides a 47% reduction of compensatory effects when considering muscle activation.

Walk Your Dizzy Patients! Gait Assessment as a Screening Tool for Posterior Circulation Stroke (S3.001)

<h3>Objective:</h3> To determine if objective gait abnormality (OGA) might be used as a cost-effective screening tool in the acute presentation of posterior circulation stroke (PSC). <h3>Background:</h3> The National Institutes of Health Stroke Scale (NIHSS) is less robust for patients with PCS due to lack of inclusion of signs and symptoms localizing to the posterior fossa. We previously showed that OGA was the most common presenting feature in this population. Our present hypothesis was that association with OGA would be greater in PCS patients than posterior stroke mimics, especially in those presenting with dizziness or subjective gait abnormality (SGA). <h3>Design/Methods:</h3> We completed a case-control study to determine odds of OGA in PCS patients and mimics, reported with confidence intervals(CI), sensitivity(SE), specificity(SP), positive predictive value(PPV), and negative predictive value(NPV). We defined PCS cases as acute ischemic strokes isolated to the posterior cerebral, basilar, or vertebral artery territories. Mimics were defined as acutely vertiginous patients from other causes. <h3>Results:</h3> We identified 82 PCS patients (average age=67, 51% female) and 104 mimics (average age=63, 51%female) with gait assessment on arrival. OGA was documented in 69/82(84.1%) PCS cases vs. 18/104(17.3%) mimics (OR=25.4, CI=11.62–55.35, SE84%, SP82%, PPV79%, NPV87%). Stratified by dizziness, OGA was documented in 38/44(86%) PCS cases vs. 18/104(17.3%) mimics (OR=30.3, CI=11.13–82.23, SE86%, SP83%, PPV68%, NPV94%). Stratified by SGA, OGA was documented in 48/52(92%) PCS cases vs. 16/74(21.6%) mimics (OR=43.5, CI=13.63–138.83, SE92%, SP78%, PPV75%, NPV94%). <h3>Conclusions:</h3> Patients at NYU Langone Hospitals with PCS were 25.4× more likely to have OGA than mimics, and 30.3× or 43.5× more likely to have OGA when presenting with dizziness or SGA. While SP and PPV remained low (&lt;90%), NPV rose to 94% in patients with dizziness and SGA on admission. Gait assessment can be used as a cost-effective screening tool to rule out PCS on arrival. Prospective studies should be accomplished prior to recommendation. <b>Disclosure:</b> Dr. Smith has nothing to disclose. Dr. Valdes has received research support from a T32 NIH Grant. Dr. Torres has nothing to disclose. Dr. Melmed has nothing to disclose.