Kinematic network of joint motion provides insight on gait coordination: An observational study on Parkinson's disease.

The analysis of gait kinematics requires to encode and collapse multidimensional information from multiple anatomical elements. In this study, we address this issue by analyzing the joints' coordination during gait, borrowing from the framework of network theory. We recruited twenty-three patients with Parkinson's disease and twenty-three matched controls that were recorded during linear gait using a stereophotogrammetric motion analysis system. The three-dimensional angular velocity of the joints was used to build a kinematic network for each participant, and both global (average whole-body synchronization) and nodal (individual joint synchronization, i.e., nodal strength) were extracted. By comparing the two groups, the results showed lower coordination in patients, both at global and nodal levels (neck, shoulders, elbows, and hips). Furthermore, the nodal strength of the left elbow and right hip in the patients, as well as the average joints' nodal strength were significantly correlated with the clinical motor condition and were predictive of it. Our study highlights the importance of integrating whole-body information in kinematic analyses and the advantages of using network theory. Finally, the identification of altered network properties of specific joints, and their relationship with the motor impairment in the patients, suggests a potential clinical relevance for our approach.

Quantitative gait markers and the TUG time in chronic kidney disease.

Background: Poor gait performance results in more fall incidents among people with chronic kidney disease (CKD). It is unknown what specific quantitative gait markers contribute to high fall risk in CKD and the size of their mediation effects. Methods: We included 634 participants from the Taizhou Imaging Study who had complete gait and laboratory data. Quantitative gait assessment was conducted with a wearable insole-like device. Factor analysis was utilized to summarize fifteen highly correlated individual parameters into five independent gait domains. Prevalent CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 m2, which was calculated based on cystatin C. Regression models were created to examine the associations of prevalent CKD with quantitative gait markers and the TUG time. Mediation analysis was used to investigate whether poor quantitative gait parameters could be mediators and the proportion of their mediation effects. Results: Participants with prevalent CKD had a higher TUG time (odds ratio = 2.02, P = 0.025) and poor gait performance in the phase domain (standardized ß = -0.391, FDR = 0.009), including less time in the swing phase (standardized ß = -0.365, FDR = 0.027) and greater time in the double-support phase (standardized ß = 0.367, FDR = 0.027). These abnormalities mediated the association of prevalent CKD with a high TUG time (for the swing phase: 31.6 %, P mediation = 0.044; for the double-support phase: 29.6 %, P mediation = 0.042; for the phase domain: 26.9 %, P mediation = 0.048). Conclusion: Poor phase-related gait abnormalities mediated the relationship between CKD and a high TUG time, suggesting that incorporating quantitative gait markers in specific domains may improve fall prevention programs for individuals with CKD.

Validation of a micro-doppler radar for measuring gait modifications during multidirectional visual perturbations.

BACKGROUND: Changes in spatio-temporal gait parameters and their variability during balance-challenging tasks are markers of motor performance linked to fall risk. Radio frequency (RF) sensors hold great promise towards achieving continuous remote monitoring of these parameters. RESEARCH QUESTIONS: To establish the concurrent validity of RF-based gait metrics extracted using micro-Doppler (µD) signatures and to determine whether these metrics are sensitive to gait modifications created by multidirectional visual perturbations. METHODS: Fifteen participants walked overground in a virtual environment (VE) and VE with medio-lateral (ML) and antero-posterior (AP) perturbations. An optoelectronic motion capture system and one RF sensor were used to extract the linear velocity of the trunk and estimate step time (ST), step velocity (SV), step length (SL), and their variability (STV, SVV, and SLV). Intra-class coefficient for consistency (ICC), mean and standard deviation of the differences (MD), 95 % limits of agreement, and Pearson correlation coefficients (r) were used to determine concurrent validity. One-way repeated-measures analysis of variance was used to analyze the main and interaction effects of visual conditions. RESULTS: All outcomes showed good to excellent reliability (r>0.795, ICC>0.886). Average gait parameters showed good to excellent agreement, with values obtained with the RF sensor systematically smaller than the values obtained with the markers (MD of 0.001 s, 0.09 m/s, and 0.06 m). Gait variability parameters showed poor to moderate agreement, with values obtained with the RF sensor systematically larger than those obtained with the markers (MD of 1.9 %-3.9 %). Both measurement systems reported decreased SL and SV during ML perturbations, but the gait variability parameters extracted with the radar were not able to detect the higher STV and SLV during this condition. SIGNIFICANCE: The radar µD signature is a valid and reliable method for the assessment of average spatio-temporal gait parameters but gait variability measures need to be viewed with caution because of the lower levels of agreement and sensitivity to ML visual perturbations. This work represents an initial investigation for the development of a low-cost system that will facilitate aging-in-place by providing remote monitoring of gait in natural settings.

Crossover effect of knee and ankle joint training on knee mechanics after ACL reconstruction: A randomized controlled trial.

BACKGROUND: Anterior cruciate ligament (ACL) rehabilitation is a common intervention after ACL reconstruction. Since different types of exercise can influence muscle and kinematic parameters in diverse ways, the training order between the knee and ankle joints may also change gait parameters. PURPOSE: This study aimed to investigate whether the training sequence of the knee and ankle joints (knee followed by ankle training or vice-versa) in an ACL reconstruction (ACLR) rehabilitation program has any effects on knee extension and flexion torques. METHODS: Forty-two men (aged 20-30 years) with ACLR participated in this study. They were randomly allocated to receive one of two interventions: (A) knee joint training followed by ankle training or (B) ankle joint training followed by knee training. After five weeks (four weeks of intervention and one-week washout), participants crossed from one group to another for an additional four weeks. Knee extension and flexion torques were assessed during the stance phase of the gait cycle before and after the intervention program. RESULTS: Two-way Mixed-design MANOVA showed that knee extension torque improved significantly in both groups after training (p = 0.001, Cohen's D = 0.65), while the knee flexion torque increased significantly only in group B (p= 0.001, Cohen's D = 0.97). When comparing both groups, patients of group B presented significant improvements in the post-training mean values of all tested variables compared with group A. CONCLUSION: Starting a post-ACLR rehabilitation program with ankle training followed by knee training is better to improve knee flexion and extension torques during the stance phase of the gait cycle than starting the program by training the knee first, followed by the ankle. Future studies using a mixed-gender sample and different types of ACLR operations are necessary to examine whether similar improvements will happen as well as to test their effects on many sports activities.

A stacked autoencoder-based aid system for severity degree classification of knee ligament rupture.

BACKGROUND: Knee ligament rupture is one of the most common injuries, but the diagnosis of its severity tends to require the use of complex methods and analyses that are not always available to patients. AIM: The objective of this research is the investigation and development of a diagnostic aid system to analyze and determine patterns that characterize the presence of the injury and its degree of severity. METHODS: Implement a novel proposal of a framework based on stacked auto-encoder (SAE) for ground reaction force (GRF) signals analysis, coming from the GaitRec database. Analysis of the raw data is used to determine the main features that allow us to diagnose the presence of a knee ligament rupture and classify its severity as high, mid or mild. RESULTS: The process is divided into two stages to determine the presence of the lesion and, if necessary, evaluate variations in features to classify the degree of severity as high, mid, and mild. The framework presents an accuracy of 87 % and a F1-Score of 90 % for detecting ligament rupture and an accuracy of 86.5 % and a F1-Score of 87 % for classifying severity. CONCLUSION: This new methodology aims to demonstrate the potential of SAE in physiotherapy applications as an evaluation and diagnostic tool, identifying irregularities associated with ligament rupture and its degree of severity, thus providing updated information to the specialist during the rehabilitation process.

Effectiveness of repetitive transcranial magnetic stimulation combined with intelligent Gait-Adaptability Training in improving lower limb function and brain symmetry after subacute stroke: a preliminary study.

OBJECTIVES: Persistent lower limb dysfunction is a major challenge in post-stroke recovery. Repetitive transcranial magnetic stimulation is recognized for addressing post-stroke motor deficits. Our study explores the efficacy of combining rTMS with gait-adaptive training to enhance lower limb function and regulatory mechanisms in subacute stroke. MATERIALS AND METHODS: This randomized controlled trial enrolled 27 patients with subacute hemiparesis, dividing them into experimental and control groups. Both groups underwent gait-adaptability training 5 times/week for 4 weeks, with the experimental group receiving daily low-frequency transcranial magnetic stimulation before training. Primary outcomes included the pairwise derived brain symmetry index, lower-extremity Fugl-Meyer Assessment, 10-meter walk test, and Berg Balance Scale. Assessments occurred before and after the four-week intervention. RESULTS: The experimental and control groups showed significant improvements in the Fugl-Meyer Assessment, 10-meter walk test, and Berg Balance Scale after the 4-week intervention compared to baseline (all p<0.05). However, the experimental group demonstrated significantly greater improvements compared to the control group in the Fugl-Meyer Assessment (p=0.024) and the 10-meter walk test (p=0.033). Additionally, the experimental group exhibited a more pronounced decrease in the pairwise derived brain symmetry index (p=0.026) compared to the control group. Within the experimental group, the cortical subgroup's pairwise derived brain symmetry index was significantly lower than that of the control group (p=0.006). CONCLUSIONS: Combining low-frequency transcranial magnetic stimulation with Gait-Adaptive Training effectively enhances lower limb function and Regulatory mechanisms of the cerebral hemisphere in subacute stroke recovery, and it can provide rapid and effective rehabilitation effect compared with gait adaptation training alone.

Real-time auditory feedback for improving gait and walking in people with Parkinson's disease: a pilot and feasibility trial.

BACKGROUND: Technology is poised to bridge the gap between demand for therapies to improve gait in people with Parkinson's and available resources. A wearable sensor, Heel2Toe™, a small device that attaches to the side of the shoe and gives a sound each time the person starts their step with a strong heel strike, has been developed and pre-tested by a team at McGill University. The objective of this study was to estimate feasibility and efficacy potential of the Heel2Toe™ sensor in changing walking capacity and gait pattern in people with Parkinson's. METHODS: A pilot study was carried out involving 27 people with Parkinson's randomized 2:1 to train with the Heel2Toe[TM] sensor and or to train with recommendations from a gait-related workbook. RESULTS: A total of 21 completed the 3-month evaluation, 14 trained with the Heel2Toe[TM] sensor, and 7 trained with the workbook. Thirteen of 14 people in the Heel2Toe group improved over measurement error on the primary outcome, the 6-Minute Walk Test, (mean change 66.4 m) and 0 of the 7 in the Workbook group (mean change - 19.4 m): 4 of 14 in the Heel2Toe group made reliable change and 0 of 7 in the Workbook group. Improvements in walking distance were accompanied by improvements in gait quality. Forty percent of participants in the intervention group were strongly satisfied with their technology experience and an additional 37% were satisfied. CONCLUSIONS: Despite some technological difficulties, feasibility and efficacy potential of the Heel2Toe sensor in improving gait in people with Parkinson's was supported.

Gait Speed Reserve in the general population-based 'Good Aging in Skåne' cohort study-distribution and associated factors.

Gait Speed Reserve (GSR) expresses a difference between fast and comfortable gait speed and may have an impact on everyday functioning. It was also hypothesized as a useful proxy measure of physiological reserve. However, height-normalizing values of GSR and its associated factors have not been evaluated in a general population of older adults. Therefore, we aimed to investigate the distribution of height-normalized GSR (HN-GSR) in an elderly population-based cohort from urban and rural areas (n = 4342) aged 60-93 years and evaluate associated physiological and lifestyle factors. Using linear mixed models, we identified gender and nine modifiable factors as significantly associated with HN-GSR across four age groups. Better handgrip strength, cognition and standing balance, higher physical activity level, larger calf circumference, and less smoking had positive associations with HN-GSR, while female gender, more leg pain, higher weight and, alcohol consumption had opposite effects. The Marginal R2 imply that this model explained 26% of the variance in HN-GSR. Physical activity and handgrip strength varied across age groups in impact on HN-GSR. The differences were however comparatively minor. In this large cohort study of older adults, we proposed for the first time that factors associated with HN-GSR represented multi-domain features that are in line with previous findings reported for GSR. Measuring HN-GSR/GSR may help clinicians identify early physiological impairments or unhealthy lifestyle habits, especially among older women, and may also have safety implications in daily life. Further work is needed to find out if measuring HN-GSR/GSR may be useful in identifying adverse health outcomes and overall physiological reserve.

A Study of Assisted Screening for Alzheimer's Disease Based on Handwriting and Gait Analysis.

Background: Alzheimer's disease (AD) is a progressive neurodegenerative disease that is not easily detected in the early stage. Handwriting and walking have been shown to be potential indicators of cognitive decline and are often affected by AD. Objective: This study proposes an assisted screening framework for AD based on multimodal analysis of handwriting and gait and explores whether using a combination of multiple modalities can improve the accuracy of single modality classification. Methods: We recruited 90 participants (38 AD patients and 52 healthy controls). The handwriting data was collected under four handwriting tasks using dot-matrix digital pens, and the gait data was collected using an electronic trail. The two kinds of features were fused as inputs for several different machine learning models (Logistic Regression, SVM, XGBoost, Adaboost, LightGBM), and the model performance was compared. Results: The accuracy of each model ranged from 71.95% to 96.17%. Among them, the model constructed by LightGBM had the best performance, with an accuracy of 96.17%, sensitivity of 95.32%, specificity of 96.78%, PPV of 95.94%, NPV of 96.74%, and AUC of 0.991. However, the highest accuracy of a single modality was 93.53%, which was achieved by XGBoost in gait features. Conclusions: The research results show that the combination of handwriting features and gait features can achieve better classification results than a single modality. In addition, the assisted screening model proposed in this study can achieve effective classification of AD, which has development and application prospects.

Gait Training Interventions for Individuals with Chronic Ankle Instability: A Systematic Review & Meta-Analysis.

OBJECTIVE: This review aimed to determine if gait training interventions influence lower extremity biomechanics during walking in individuals with chronic ankle instability (CAI). METHODS: A literature search was conducted in PubMed, CINAHL, SPORTDiscus, and MEDLINE to identify English-language studies from inception through September 2022. Eligible studies included randomized control trials, repeated measures design, and descriptive laboratory studies measuring the effects during or following a gait training intervention on biomechanical outcomes (kinematics, kinetics, electromyography) during walking in individuals with CAI. Gait training interventions were broadly categorized into devices (destabilization devices, novel gait training device) and biofeedback (visual, auditory, and haptic delivery modes). Meta-analyses were conducted when appropriate using random-effects to compare pre-and post- gait training intervention mean differences and standard deviations. RESULTS: Thirteen studies were included. Meta-analyses were conducted for single session gait training studies only. Eleven studies reported kinetic outcomes. Our meta-analyses showed location of center of pressure (COP) was shifted medially from 0-90% (Effect Size [ES] range=0.35-0.82) of stance, contact time was decreased in medial forefoot (ES=0.43), peak pressure was decreased for lateral midfoot (ES=1.18) and increased for hallux (ES=0.59), pressure time integral was decreased for lateral heel (ES=0.33) and lateral midfoot (ES=1.22) and increased for hallux (ES=0.63). Three studies reported kinematic outcomes. Seven studies reported electromyography outcomes. Our meta-analyses revealed increased activity following initial contact (IC) for fibularis longus (ES=0.83). CONCLUSIONS: Gait training protocols improved some lower extremity biomechanical outcomes in individuals with CAI. Plantar pressure outcome measures seem to be most impacted by gait training programs with improvements in decreasing lateral pressure associated with increased risk for lateral ankle sprains. Gait training increased EMG activity post-IC for the fibularis longus. Few studies have assessed the impact of multi-session gait training on biomechanical outcome measures. Targeted gait trainning should be considered when treating patients with CAI.

Automatic Detection of Fatigued Gait Patterns in Older Adults: An Intelligent Portable Device Integrating Force and Inertial Measurements with Machine Learning.

PURPOSE: This study aimed to assess the feasibility of early detection of fatigued gait patterns for older adults through the development of a smart portable device. METHODS: The smart device incorporated seven force sensors and a single inertial measurement unit (IMU) to measure regional plantar forces and foot kinematics. Data were collected from 18 older adults walking briskly on a treadmill for 60 min. The optimal feature set for each recognition model was determined using forward sequential feature selection in a wrapper fashion through fivefold cross-validation. The recognition model was selected from four machine learning models through leave-one-subject-out cross-validation. RESULTS: Five selected characteristics that best represented the state of fatigue included impulse at the medial and lateral arches (increased, p = 0.002 and p < 0.001), contact angle and rotation range of angle in the sagittal plane (increased, p < 0.001), and the variability of the resultant swing angular acceleration (decreased, p < 0.001). The detection accuracy based on the dual signal source of IMU and plantar force was 99%, higher than the 95% accuracy based on the single source. The intelligent portable device demonstrated excellent generalization (ranging from 93 to 100%), real-time performance (2.79 ms), and portability (32 g). CONCLUSION: The proposed smart device can detect fatigue patterns with high precision and in real time. SIGNIFICANCE: The application of this device possesses the potential to reduce the injury risk for older adults related to fatigue during gait.

Efficacy of exercise interventions combined with Selegiline in ameliorating freezing of gait in Parkinson's disease patients.

OBJECTIVE: To evaluate the efficacy of exercise interventions combined with Selegiline in ameliorating freezing of gait (FOG) in Parkinson's disease (PD) patients. METHODS: A total of 60 PD patients with FOG treated in the First People's Hospital of Fuyang District from January 2020 to January 2023 were retrospectively collected and analyzed. Patients were divided into a control group (n = 28, treated with Selegiline alone) and an observation group (n = 32, treated with Selegiline and exercise interventions). Gait parameters, FOG indices, motor and balance functions, Berg Balance, psychological status, and quality of life were compared between the groups pre- and post-treatment. RESULTS: After treatment, the observation group exhibited longer step length, higher step speed, and lower step frequency (P = 0.000, 0.003, 0.001, respectively), with enhanced balance as indicated by lower Timed Up and Go Test and higher Berg Balance Scale scores than the control group (P = 0.000, 0.000, respectively). The Beck Depression Inventory and Beck Anxiety Inventory scores were notably lower in the observation group than those in the control group (P = 0.000, 0.004, respectively). Additionally, the observation group showed better quality of life across several dimensions of the Parkinson's Disease Quality of Life Questionnaire, including mobility, activities of daily living, emotional well-being, stigma, social support, cognition, communication, and bodily discomfort (P = 0.000, 0.000, 0.000, 0.000, 0.017, 0.000, 0.000, 0.000, respectively) than the control group. CONCLUSION: The combination of exercise interventions and Selegiline effectively rectifies the gait parameters, enhances the balance function, alleviates psychological distress, and improves the overall quality of life in PD patients experiencing FOG.

Development of a novel geometrically-parametric patient-specific finite element model for anterior cruciate ligament reconstruction.

PURPOSE: A personalized model of the knee joint, with adjustable effective geometric parameters for the transplanted autograft diameter in Anterior Cruciate Ligament Reconstruction (ACLR) using the bone-patella-tendon-bone (BPTB) technique, has been developed. The model will assist researchers in understanding how different graft sizes impact a patient's recovery over time. METHODS: The study involved selecting a group of individuals without knee injuries and one patient who had undergone knee surgery. Gait analysis was conducted on the control group and the patient at various time points. A 3D model of the knee joint was created using medical images of the patient. Forces and torques obtained from the gait analysis were applied to the model to perform finite element analysis. RESULTS: The results of the finite element (FE) analysis, along with kinetic data from both groups, indicate that models with diameters of 7.5 mm and 12 mm improved joint motion during follow-up after ACLR. Additionally, a comparison of the stress applied to the ACL model revealed that a 12 mm autograft diameter showed a more favorable trend in patient recovery during the three follow-up intervals after ACL reconstruction surgery. CONCLUSION: The development of a personalized parametric model with adjustable geometric parameters in ACLR, such as the transplanted autograft diameter, as presented in this study, along with FE using the patient's kinetic data, allows for the examination and selection of an appropriate autograft diameter for Patella Tendon grafting. This can help reduce stress on the autograft and prevent damage to other knee joint tissues after ACLR.

Ability of a multi-segment foot model to measure kinematic differences in cavus, neutrally aligned, asymptomatic planus, and symptomatic planus foot types.

BACKGROUND: Multi-segment foot models (MFMs) provide a better understanding of the intricate biomechanics of the foot, yet it is unclear if they accurately differentiate foot type function during locomotion. RESEARCH QUESTION: We employed an MFM to detect subtle kinematic differences between foot types, including: pes cavus, neutrally aligned, and asymptomatic and symptomatic pes planus. The study investigates how variable the results of this MFM are and if it can detect kinematic differences between pathologic and non-pathologic foot types during the stance phase of gait. METHODS: Independently, three raters instrumented three subjects on three days to assess variability. In a separate cohort, each foot type was statically quantified for ten subjects per group. Each subject walked while instrumented with a four-segment foot model to assess static alignment and foot motion during the stance phase of gait. Statistical analysis performed with a linear mixed effects regression. RESULTS: Model variability was highest for between-day and lowest for between-rater, with all variability measures being within the true sample variance. Almost all static measures (radiographic, digital scan, and kinematic markers) differed significantly by foot type. Sagittal hindfoot to leg and forefoot to leg kinematics differed between foot types during late stance, as well as coronal hallux to forefoot range of motion. The MFM had low between-rater variability and may be suitable for multiple raters to apply to a single study sample without introducing significant error. The model, however, only detected a few dynamic differences, with the most dramatic being the hallux to forefoot coronal plane range of motion. SIGNIFICANCE: Results only somewhat aligned with previous work. It remains unclear if the MFM is sensitive enough to accurately detect different motion between foot types (pathologic and non-pathologic). A more accurate method of tracking foot bone motion (e.g., biplane fluoroscopy) may be needed to address this question.

Perturbation-based balance training of older adults and effects on physiological, cognitive and sociopsychological factors: a secondary analysis from a randomised controlled trial with 12-month follow-up.

BACKGROUND: Perturbation-based balance training (PBT) has shown promising, although diverging, fall-preventive effects; however, the effects on important physical, cognitive and sociopsychological factors are currently unknown. The study aimed to evaluate these effects on PBT at three different time points (post-training, 6-months and 12-months) in community-dwelling older adults compared with regular treadmill walking. METHODS: This was a preplanned secondary analysis from a randomised, controlled trial performed in Aalborg, Denmark, between March 2021 and November 2022. Community-dwelling older adults aged ≥65 were randomly assigned to participate in four sessions (lasting 20 min each) of either PBT (intervention) or regular treadmill walking (control). All participants were assigned to four testing sessions: pretraining, post-training, 6-month follow-up and 12-month follow-up. At these sessions, physical, cognitive and sociopsychological measures were assessed. RESULTS: In total, 140 participants were randomly allocated to either the PBT or control group. Short-term (pretraining to post-training) between-group differences were seen for choice stepping reaction time (-49 ms, 95% CI -80 to -18), dual-task gait speed (0.05 m/s, 95% CI 0.01 to 0.09) favouring the PBT group. However, these improvements were not sustained at the 6-month and 12-month follow-up. No significant between-group differences were found in other physical, cognitive or sociopsychological factors. CONCLUSIONS: This study showed that PBT, in the short term, improved choice stepping reaction time and dual-task gait speed among community-dwelling older adults. Yet, these improvements were not retained for 6- or 12-months. The healthy state of the study's population may have imposed a ceiling effect limiting the ability to show any clinically relevant effects of PBT. TRIAL REGISTRATION NUMBER: NCT04733222.

Prognostic role of gait speed in worsening heart failure.

BACKGROUND: Worsening Heart Failure (WHF) is associated with adverse prognosis. Identifying novel prognostic markers in WHF is crucial. Gait speed (GS), a validated frailty index, is an easily obtainable parameter that may aid in reclassifying the risk of HF patients. We assessed the independent prognostic role of GS in WHF patients. METHODS: We studied 171 patients with chronic HF with worsening congestion symptoms and inadequate response to standard therapies, requiring intravenous diuretic treatment. The primary outcome was a composite of all-cause mortality or HF hospitalization. We assessed the association and the incremental value of GS, as compared to other clinical confounders, with the primary outcome. RESULTS: The mean age was 76±11 years, 66 % were male, median BNP was 481 pg/ml, and median ejection fraction was 40 %. Over a median follow-up of 11.3 months, 71 events occurred. Lower GS was significantly associated with a higher risk of events (HR of 4.03, 95 % CI 2.25-7.21), along with neutrophil to lymphocyte ratio, BNP, QRS duration, natremia, and previous myocardial infarction. When added to the MAGGIC risk score and the other significant confounders identified, GS significantly enhanced the model risk prediction (Harrell's C-index 0.75 vs 0.71, p < 0.001). At Classification And Regression Tree analysis, GS≤0.8 m/s was the first parameter to be considered to risk stratify the population. CONCLUSIONS: GS, an easily obtainable marker of frailty, may contribute to improve the risk stratification of patients with WHF.

Unraveling stroke gait deviations with movement analytics, more than meets the eye: a case control study.

Background: This study aimed to identify and quantify the kinematic and kinetic gait deviations in post-stroke hemiplegic patients with matched healthy controls using Statistical Parametric Mapping (SPM). Methods: Fifteen chronic stroke patients [4 females, 11 males; age 53.7 (standard deviation 12.2) years; body mass 65.4 (10.4) kg; standing height 168.5 (9.6) cm] and 15 matched healthy controls [4 females, 11 males; age 52.9 (11.7) years; body weight 66.5 (10.7) years; standing height 168.3 (8.8) cm] were recruited. In a 10-m walking task, joint angles, ground reaction forces (GRF), and joint moments were collected, analyzed, and compared using SPM for an entire gait cycle. Results: Generally, when comparing the stroke patients' affected (hemiplegic) and less-affected (contralateral) limbs with the control group, SPM identified significant differences in the late stance phase and early swing phase in the joint angles and moments in bilateral limbs (all p < 0.005). In addition, the vertical and anteroposterior components of GRF were significantly different in various periods of the stance phase (all p < 0.005), while the mediolateral component showed no differences between the two groups. Conclusion: SPM was able to detect abnormal gait patterns in both the affected and less-affected limbs of stroke patients with significant differences when compared with matched controls. The findings draw attention to significant quantifiable gait deviations in the less-affected post-stroke limb with the potential impact to inform gait retraining strategies for clinicians and physiotherapists.

A Falls Prevention Program for People After Stroke in Guyana: An International Collaboration.

OBJECTIVE: The objective was to describe the social, environmental, and cultural adaptations to an existing falls program and assess acceptability and preliminary effectiveness of the program in reducing fear, reducing falls, and improving function among individuals poststroke in Guyana. METHODS: A quasi-experimental pilot study with a pretest/ posttest in-group design was developed through a collaboration of researchers in Guyana and the US. Participants took part in the falls prevention program for 8 weeks. Outcome measures included a 10-meter walk test, Five Times Sit to Stand, and subjective questionnaires for falls incidence and balance confidence at the beginning and end. RESULTS: Twenty participants completed the study. One participant experienced medical complications and their data were excluded from analysis. Fifteen participants (78.9%) demonstrated improvements in comfortable and fast walking speed. Twelve participants completed the Five Times Sit to Stand Test. Eleven (91.67%) improved their time at posttest, with 9 (81.8%) demonstrating a clinically important improvement. Nineteen participants had sustained at least 1 fall prior to the study. Only 1 participant reported a fall during the program. Initially, the majority of participants (11/19) were very concerned about falling. At the end, only 1 was very concerned about falling, and the majority (15/19) were not concerned at all. Post-test surveys of participants indicated acceptability of the program. CONCLUSIONS: This pilot program helped reduce fall risk and improve confidence, gait speed and community mobility of the study participants. Future research at other rehabilitation departments in Guyana would help increase generalizability of the program. IMPACT STATEMENT: The program can be used clinically by physical therapists in Guyana both in departments and as a home program. Shared knowledge and experience of researchers considering research evidence and the environmental, social, and economic conditions of people living in Guyana were important in developing an effective program.

Presentation of multiple task instructional sets impacts auditory Stroop performance during dual task locomotion.

The auditory Stroop is a modification of the classic Stroop paradigm commonly used in dual-task research when the motor task requires the visual system. Despite its use, there are gaps in our understanding of this tool. For example, in visual/auditory Stroop paradigms, neutral cues irrelevant to the required response, which theoretically cause less interference/facilitation, are used to elucidate effects of visual/auditory demands on neural processes. Specifically, in auditory Stroop paradigms the use and choice of neutral cue words is inconsistent. To address these gaps, we instrumented participants with kinematic markers and a digital microphone and asked them to respond to auditory Stroop cues and neutral cue words consisting of either one or two syllables, while simultaneously performing an unobstructed locomotor task. Two blocks of trials were collected. In one block, participants had prior knowledge that either an auditory Stroop or a neutral word stimulus would be presented (Known); a second block presented both types of cognitive cues in a random order to participants (Mixed). We observed main effects of cognitive task (neutral, incongruent, congruent) and instructional set (Known, Mixed) on response times, but not on center of mass velocity. Also, more time was required to verbally respond to an incongruent compared to congruent or neutral task across all conditions, and neutral task words with one syllable resulted in longer response times compared to two syllable neutral words. We recommend that researchers include neutral cues when using the auditory Stroop test and to carefully consider their neutral word choice.

Walking against the odds: The intricate connection between spatiotemporal characteristics, kinetic and kinematic variables, cognitive stress, and passive assistive exoskeletons in senior and young adults.

In this study, we investigated the combined effects of age, dual-tasking (DT) and a passive hip exoskeleton on gait patterns among senior (SA) and young adults (YA). It was hypothesized that SA will be more affected by DT and that wearing the exoskeleton will improve gait patterns for both groups during DT. Twenty-two SA and twenty-six YA performed a single task (normal walking) and DT walking at their preferred speed with an exoskeleton (EXO), without (noEXO), and a sham version (SHAM) in a randomized and balanced order. Speed, cadence, double support time (DST), step length, hip joint power, range of motion (ROM), and moments (mom), as well as DT performance, were extracted using mocap, force plates (1000 Hz), and a voice recorder. Three-way MANOVA with group × device × condition was conducted (p < .05, inferred significance). Results showed a predominantly significant main effect of group for step length, speed, DST, ROM, and mom (p ≤ .01), main effect of condition for cadence, DST, speed, and mom (p < .01) and a main effect of the device for ROMz and mom (p < .05). Age-related changes were seen by decreased walking speed and step length, independent of DT and use of exoskeleton. Wearing the EXO aided the SA group to maintain similar levels of cadence from single to DT and decreased the hip internal rotation mom by 65%. There was no difference in DT performance between groups. In conclusion, SA showed a decline in gait patterns during DT that was somewhat mitigated by wearing an EXO.