Jeffrey M Hausdorff

• PhD
• Tel Aviv Sourasky Medical Center

Hemodynamic homeostasis is essential for adapting the heart rate (HR) to postural and physiological changes during daily activities. Traditional HR monitoring, such as 24 hour (h) Holter monitoring, provides important information on homeostasis during daily living. However, this approach lacks concurrent activity recording, limiting insights into h...

Background/Objectives: Parkinson’s Disease (PD) and other forms of parkinsonism share motor symptoms, including tremor, bradykinesia, and rigidity. The overlap in their clinical presentation creates a diagnostic challenge, as conventional methods rely heavily on clinical expertise, which can be subjective and inconsistent. This highlights the need...

This report summarizes the existing literature on the use of technology for the assessment of freezing of gait (FOG) as well as the use of technology to provide insights into the mechanisms of FOG in people with Parkinson's disease. Specifically, this work was carried out for the 3rd International Workshop on Freezing of Gait in Jerusalem in 2025....

Background Wider step width and lower step‐to‐step variability are linked to improved gait stability and reduced fall risk. It is unclear if patients with spinocerebellar ataxia (SCA) can learn to adjust these aspects of gait to reduce fall risk. Objectives The aims were to examine the possibility of using wearable step width haptic biofeedback to...

Introduction Freezing of gait (FOG) is a disabling symptom for people with Parkinson’s disease (PwPD). Turning on the spot for one minute in alternating directions (360 turn) while performing a cognitive dual-task (DT) is a fast and sensitive way to provoke FOG. The FOG-index is a widely used wearable sensor-based algorithm to quantify FOG severity...

Few studies have analyzed sensor-derived metrics of both mobility abilities and total daily physical activity (TDPA). We sought to determine if sensor-derived mobility metrics and quantitative indices of TDPA were independently associated with prevalent and incident mobility disability. Quantitative mobility metrics from 724 ambulatory adults (mean...

Mobility tasks like the Timed Up and Go test (TUG), cognitive TUG (cogTUG), and walking with turns provide insights into the impact of Parkinson’s disease (PD) on motor control, balance, and cognitive function. We assess the test–retest reliability of these tasks in 262 PD participants and 50 controls by evaluating machine learning models based on...

Wearable sensors offer a non-invasive way to collect physical activity (PA) data, with walking as a key component. Existing models often struggle to detect gait bouts in individuals with neurodegenerative diseases (NDDs) involving involuntary movements. We developed J-Net, a deep learning model inspired by U-Net, which uses a pre-trained self-super...

BACKGROUND Recent technological advances in wearable devices offer new potential for measuring mobility in real-world contexts. Mobilise-D has validated digital mobility outcomes to provide novel outcomes and endpoints in clinical research of four different long-term health conditions (Parkinson’s disease (PD), Multiple Sclerosis (MS), Chronic Obst...

Introduction: Walking impairment is an important risk factor for falls, hospitalisations and mortality. Yet, guidelines still have to be defined for obtaining valid and reliable walking activity (e.g., number of steps per day) and gait (e.g., walking speed) parameters in the real world. Objectives: i) identify the minimal daily wearing time during...

BACKGROUND Algorithms estimating real-world digital mobility outcomes (DMOs) are increasingly validated in healthy adults and various disease cohorts. However, their accuracy and reliability in older adults after hip fractures, who often walk slowly for short durations, is underexplored. OBJECTIVE The objective of this study was to examine DMO acc...

Background Few studies have analyzed sensor-derived metrics of mobility abilities and total daily physical activity (TDPA). We tested whether sensor-derived mobility metrics and TDPA indices are independently associated with mobility disabilities. Methods This cohort study derived mobility abilities from a belt-worn sensor that recorded annual sup...

Step width is vital for gait stability, postural balance control, and fall risk reduction. However, estimating step width typically requires either fixed cameras or a full kinematic body suit of wearable inertial measurement units (IMUs), both of which are often too expensive and time-consuming for clinical application. We thus propose a novel data...

Background Wearable sensors can evaluate daily-living gait in HD; however, the accuracy of gait detection algorithms in the presence of chorea remains unclear. Aims To develop an algorithm that accurately detects daily-living gait in HD using a wrist-worn accelerometer. Methods Tri-axial accelerometer data were collected in HD (n=21; age:58.1±11....

Progressive gait impairment is common among aging adults. Remote phenotyping of gait during daily living has the potential to quantify gait alterations and evaluate the effects of interventions that may prevent disability in the aging population. Here, we developed ElderNet, a self-supervised learning model for gait detection from wrist-worn accele...

Importance Difficulties in identifying modifiable risk factors associated with daily physical activity may impede public health efforts to mitigate the adverse health outcomes of a sedentary lifestyle in an aging population. Objective To test the hypothesis that adding baseline sensor-derived mobility metrics to diverse baseline motor and nonmotor...

Plain Language Summary Freezing of gait is a very burdensome and episodic symptom in Parkinson’s disease that is difficult to measure. Measurement of freezing is needed to determine whether someone has freezing and how severe this is, and relies on observation during a freezing-triggering protocol. However, it is unclear what protocol is sufficient...

Quantitative mobility analysis using wearable sensors, while promising as a diagnostic tool for Parkinson’s disease (PD), is not commonly applied in clinical settings. Major obstacles include uncertainty regarding the best protocol for instrumented mobility testing and subsequent data processing, as well as the added workload and complexity of this...

Freezing of gait (FOG) is a debilitating problem that markedly impairs the mobility and independence of 38-65% of people with Parkinson’s disease. During a FOG episode, patients report that their feet are suddenly and inexplicably “glued” to the floor. The lack of a widely applicable, objective FOG detection method obstructs research and treatment....

Step length is an important diagnostic and prognostic measure of health and disease. Wearable devices can estimate step length continuously (e.g., in clinic or real-world settings), however, the accuracy of current estimation methods is not yet optimal. We developed machine-learning models to estimate step length based on data derived from a single...

Background Trait and state physical fatigue (trait-PF and state-PF) negatively impact many people with multiple sclerosis (pwMS) but are challenging symptoms to measure. In this observational study, we explored the role of specific gait and autonomic nervous system (ANS) measures (i.e., heart rate, HR, r–r interval, R–R, HR variability, HRV) in tra...

Background Wrist-worn inertial sensors are used in digital health for evaluating mobility in real-world environments. Preceding the estimation of spatiotemporal gait parameters within long-term recordings, gait detection is an important step to identify regions of interest where gait occurs, which requires robust algorithms due to the complexity of...

Objective The objective of this study was to identify gait alterations related to worsening knee pain and worsening physical function, using machine learning approaches applied to wearable sensor–derived data from a large observational cohort. Methods Participants in the Multicenter Osteoarthritis Study (MOST) completed a 20‐m walk test wearing in...

Background Cueing can alleviate freezing of gait (FOG) in people with Parkinson's disease (PD), but using the same cues continuously in daily life may compromise effectiveness. Therefore, we developed the DeFOG‐system to deliver personalized auditory cues on detection of a FOG episode. Objectives We aimed to evaluate the effects of DeFOG during a...

Progressive gait impairment is common in aging adults. Remote phenotyping of gait during daily living has the potential to quantify gait alterations and evaluate the effects of interventions that may prevent disability in the aging population. Here, we developed ElderNet, a self-supervised learning model for gait detection from wrist-worn accelerom...

This study aimed to validate a wearable device's walking speed estimation pipeline, considering complexity, speed, and walking bout duration. The goal was to provide recommendations on the use of wearable devices for real-world mobility analysis. Participants with Parkinson's Disease, Multiple Sclerosis, Proximal Femoral Fracture, Chronic Obstructi...

This study aimed to validate a wearable device’s walking speed estimation pipeline, considering complexity, speed, and walking bout duration. The goal was to provide recommendations on the use of wearable devices for real-world mobility analysis. Participants with Parkinson’s Disease, Multiple Sclerosis, Proximal Femoral Fracture, Chronic Obstructi...

Wearable technology has rapidly advanced, opening new possibilities for context-aware applications in fields such as healthcare and gait analysis, where distinguishing between indoor and outdoor environments is essential. This is often accomplished through technologies like GPS, Wi-Fi, cellular, and Bluetooth which, however, come with privacy conce...

Wearable technology has rapidly evolved, enabling the integration of various sensors and algorithms, opening new possibilities for context-aware applications in fields such as healthcare, fitness tracking, and environmental monitoring. The discrimination between indoor and outdoor environments is crucial. This is often accomplished through technolo...

Background Real‐world monitoring using wearable sensors has enormous potential for assessing disease severity and symptoms among persons with Parkinson's disease (PD). Many distinct features can be extracted, reflecting multiple mobility domains. However, it is unclear which digital measures are related to PD severity and are sensitive to disease p...

Freezing of gait (FOG) is a debilitating problem that is common among many, but not all, people with Parkinson’s disease (PD). Numerous attempts have been made at treating FOG to reduce its negative impact on fall risk, functional independence, and health-related quality of life. However, optimal treatment remains elusive. Observational studies hav...

Age‐related alterations in physiology lead to declines in physical function that are associated with numerous adverse outcomes among older adults. Utilizing a hybrid design, we aimed to understand whether both long‐term and short‐term Tai Chi (TC) training are associated with age‐related decline in physical function in healthy older adults. We firs...

Introduction The clinical assessment of mobility, and walking specifically, is still mainly based on functional tests that lack ecological validity. Thanks to inertial measurement units (IMUs), gait analysis is shifting to unsupervised monitoring in naturalistic and unconstrained settings. However, the extraction of clinically relevant gait paramet...

Parkinson's disease (PD) affects 10 million people globally. PD causes unstable gait and falls in 70% of the patients and leads to many negative outcomes. Treadmill training is effective in improving gait and reducing falls, especially when combined with gait adaptations. However, the neural mechanisms behind these effects are unclear. Within Steps...

Background Gait characteristics are important risk factors for falls, hospitalisations, and mortality in older adults, but the impact of COPD on gait performance remains unclear. We aimed to identify differences in gait characteristics between adults with COPD and healthy age-matched controls during (1) laboratory tests that included complex moveme...

Background People living with Parkinson's disease (PD) have a high risk for falls. Objective To examine gaps in falls prevention targeting people with PD as part of the Task Force on Global Guidelines for Falls in Older Adults. Methods A Delphi consensus process was used to identify specific recommendations for falls in PD. The current narrative...

Objectives: There has been recent interest in the administration of transcranial electrical stimulation (tES) by a caregiver, family member, or patient themselves while in their own homes (HB-tES). The need to properly train individuals in the administration of HB-tES is essential, and the lack of a uniform training approach across studies has com...

Background Evidence exists demonstrating the negative impacts of chronic musculoskeletal pain on key measures of gait. Despite neck pain being the second most common musculoskeletal pain condition, there is a paucity of evidence exploring the impacts of neck pain specifically on these outcomes. The aims of this work were to systematically review th...

BACKGROUND Wrist worn inertial sensors are used in digital health for evaluating mobility in real-world environments. Preceding the estimation of spatio-temporal gait parameters within continuous long-term recordings, gait detection is an important step to identify regions of interest where gait occurs, which requires robust algorithms due to the c...

Background: In amyotrophic lateral sclerosis (ALS), gait abnormalities contribute to poor mobility and represent a relevant risk for falls. To date, gait studies in ALS patients focused on the motor dimension of the disease, underestimating the cognitive aspects. Methods: Using a wearable gait analysis device, we compared gait patterns in ambula...

Background Although digital mobility outcomes (DMOs) can be readily calculated from real-world data collected with wearable devices and ad-hoc algorithms, technical validation is still required. The aim of this paper is to comparatively assess and validate DMOs estimated using real-world gait data from six different cohorts, focusing on gait sequen...

Background Estimation of walking speed from wearable devices requires combining a set of algorithms in a single analytical pipeline. The aim of this study was to validate a pipeline for walking speed estimation and assess its performance across different factors (complexity, speed, and walking bout duration) to make recommendations on the use and v...

Objective: The purpose of this study was to examine the association between frailty and the quantity and quality of free-living walking and the mediating effect of frailty on the relationship between disability and walking performance in people with multiple sclerosis (MS). Methods: Ninety-nine people with relapsing-remitting MS (mean age = 49.3...

Stress tests, e.g., the cardiac stress test, are standard clinical screening tools aimed to unmask clinical pathology. As such stress tests indirectly measure physiological reserves. The term reserve has been developed to account for the dis-junction, often observed, between pathology and clinical manifestation. It describes a physiological capacit...

This study characterized person-specific rates of change of total daily physical activity (TDPA) and identified correlates of this change. TDPA metrics were extracted from multiday wrist-sensor recordings from 1083 older adults (average age 81 years; 76% female). Thirty-two covariates were collected at baseline. A series of linear mixed-effect mode...

Introduction: Accurately assessing people’s gait, especially in real-world conditions and in case of impaired mobility, is still a challenge due to intrinsic and extrinsic factors resulting in gait complexity. To improve the estimation of gait-related digital mobility outcomes (DMOs) in real-world scenarios, this study presents a wearable multi-sen...

Intensive rehabilitation programs improve motor and non-motor symptoms in people with Parkinson’s disease (PD), however, it is not known whether transfer to daily-living walking occurs. The effects of multidisciplinary-intensive-outpatient rehabilitation (MIOR) on gait and balance in the clinic and on everyday walking were examined. Forty-six (46)...

Background This study aimed to explore the acceptability of a wearable device for remotely measuring mobility in the Mobilise-D technical validation study (TVS), and to explore the acceptability of using digital tools to monitor health. Methods Participants ( N = 106) in the TVS wore a waist-worn device (McRoberts Dynaport MM + ) for one week. Fol...

Accurately assessing people's gait, especially in real-world conditions and in case of impaired mobility, is still a challenge due to intrinsic and extrinsic factors resulting in gait complexity. To improve the estimation of gait-related digital mobility outcomes (DMOs) in real-world scenarios, this study presents a wearable multi-sensor system (IN...

Background Juvenile myoclonic epilepsy (JME) is characterized by generalized seizures. Nearly 30% of JME patients are drug‐resistant (DR‐JME), indicating a widespread cortical dysfunction. Walking is an important function that necessitates orchestrated coordination of frontocentral cortical regions. However, gait alterations in JME have been scarce...

Gait alterations in those with mild unilateral knee pain during walking may provide clues to modifiable alterations that affect progression of knee pain and osteoarthritis (OA). To examine this, we applied machine learning (ML) approaches to gait data from wearable sensors in a large observational knee OA cohort, the Multicenter Osteoarthritis (MOS...

Stress tests, e.g., the cardiac stress test, are standard clinical screening tools aimed to unmask clinical pathology. As such stress tests indirectly measure physiological reserves. The term reserve has been developed to account for the disjunction, often observed, between pathology and clinical manifestation. It describes a physiological capacity...

Introduction Epidemiological evidence suggests that both poor cardiovascular fitness and low muscle mass or strength markedly increase the rate of cognitive decline and incident dementia in older adults. Results from exercise trials for the improvement of cognition in older adults with mild cognitive impairment (MCI) have reported mixed results. Th...

Background Measuring mobility in daily life entails dealing with confounding factors arising from multiple sources, including pathological characteristics, patient specific walking strategies, environment/context, and purpose of the task. The primary aim of this study is to propose and validate a protocol for simulating real-world gait accounting f...

Background: The performance of an attention-demanding task while walking, i.e., dual-tasking, leads to dual-task costs (e.g., reduced gait speed) in older adults. Previous studies have shown that dual-task costs in gait are associated with future falls and cognitive decline. According to the communication through coherence hypothesis, transcranial...

Objective: Stroke and small vessel disease cause gait disturbances and falls. The naturally occurring loss-of-function mutation (LOFM) in the C-C Chemokine receptor 5 gene (CCR5-Δ32), has recently been reported as a protective factor in post-stroke motor and cognitive recovery. We sought to examine whether it also influences gait and balance measu...

Treadmill training (TT) has been extensively used as an intervention to improve gait and mobility in patients with Parkinson's disease (PD). Regional and global effects on brain activity could be induced through TT. Training effects can lead to a beneficial shift of interregional connectivity towards a physiological range. The current work investig...

Background Motor and cognitive impairments impact the everyday functioning of people with MS (pwMS). The present randomized controlled trial (RCT) evaluated the benefits of a combined motor–cognitive virtual reality training program on key motor and cognitive symptoms and related outcomes in pwMS.Methods In a single-blinded, two-arm RCT, 124 pwMS w...

Abstract Background In older adults, the extent to which performing a cognitive task when standing diminishes postural control is predictive of future falls and cognitive decline. The neurophysiology of such “dual-tasking” and its effect on postural control (i.e., dual-task cost) in older adults are poorly understood. The purpose of this study was...

Background The development of optimal strategies to treat impaired mobility related to ageing and chronic disease requires better ways to detect and measure it. Digital health technology, including body worn sensors, has the potential to directly and accurately capture real-world mobility. Mobilise-D consists of 34 partners from 13 countries who ar...

Background The development of optimal strategies to treat impaired mobility related to ageing and chronic disease requires better ways to detect and measure it. Digital health technology, including body worn sensors, has the potential to directly and accurately capture real-world mobility. Mobilise-D consists of 34 partners from 13 countries who ar...

Introduction Real-world (RW) gait analysis is becoming increasingly important since in these conditions an individual’s mobility performance can be measured, in addition to what happens in a standardised lab environment, where mobility capacity is assessed. This is even more relevant in the presence of a motor disability, when continuous daily-life...

Objective: Freezing of gait (FOG) is an episodic, debilitating phenomenon that is common among people with Parkinson disease. Multiple approaches have been used to quantify FOG, but the relationships among them have not been well studied. In this cross-sectional study, we evaluated the associations among FOG measured during unsupervised daily-livi...

Introduction: Aging affects the interplay between cognition and gait performance. Neuroimaging studies reported associations between gait performance and structural measures; however, functional connectivity (FC) analysis of imaging data can help to identify dynamic neural mechanisms underlying optimal performance. Here, we investigated the effect...

Background: falls and fall-related injuries are common in older adults, have negative effects on functional independence and quality of life and are associated with increased morbidity, mortality and health related costs. Current guidelines are inconsistent, with no up-to-date, globally applicable ones present. Objectives: to create a set of evi...

Remote assessment of the gait of older adults (OAs) during daily living using wrist-worn sensors has the potential to augment clinical care and mobility research. However, hand movements can degrade gait detection from wrist-sensor recordings. To address this challenge, we developed an anomaly detection algorithm and compared its performance to fou...

Background Falls in older adults are a significant and growing public health concern. There are multiple risk factors associated with falls that may be addressed within the scope of chiropractic training and licensure. Few attempts have been made to summarize existing evidence on multimodal chiropractic care and fall risk mitigation. Therefore, the...

Abstract Background Lewy body dementia (LBD) is an aggressive type of dementia of rapid, fluctuating disease trajectory, higher incidence of adverse events, and poorer functional independence than observed in Alzheimer’s disease dementia. Non-pharmacological treatments such as progressive, high-intensity exercise are effective in other neurological...

We tested the hypothesis that dividing attention would strengthen the ability to detect mild cognitive impairment (MCI) and specific cognitive abilities from Timed Up and Go (TUG) performance in the community setting. While wearing a belt-worn sensor, 757 dementia-free older adults completed TUG during two conditions, with and without a concurrent...

Background . Physical activity is lower in people with multiple sclerosis (pwMS) compared to healthy controls. Previous work focused on studying activity levels or activity volume, but studies of daily-living rest-activity fragmentation patterns, circadian rhythms, and fractal regulation in pwMS are limited. Based on findings in other cohorts, one...

Wearable data is a rich source of information that can provide a deeper understanding of links between human behaviors and human health. Existing modelling approaches use wearable data summarized at subject level via scalar summaries in regression, temporal (time-of-day) curves in functional data analysis (FDA), and distributions in distributional...

Gait alterations in those with mild unilateral knee pain during walking may provide clues to modifiable alterations that affect progression of knee pain and osteoarthritis(OA). To examine this, we applied machine learning (ML) approaches to gait data from wearable sensors in a large observational knee OA cohort, the Multicenter Osteoarthritis (MOST...

There is growing interest in the quantification of gait as part of complex motor tasks. This requires gait events (GEs) to be detected under conditions different from straight walking. This study aimed to propose and validate a new marker-based GE detection method, which is also suitable for curvilinear walking and step negotiation. The method was...