Moran Dorfman

Executive Function and Falls in Older Adults: New Findings from a Five-Year Prospective Study Link Fall Risk to Cognition

Background Recent findings suggest that executive function (EF) plays a critical role in the regulation of gait in older adults, especially under complex and challenging conditions, and that EF deficits may, therefore, contribute to fall risk. The objective of this study was to evaluate if reduced EF is a risk factor for future falls over the course of 5 years of follow-up. Secondary objectives were to assess whether single and dual task walking abilities, an alternative window into EF, were associated with fall risk. Methodology/Main Results We longitudinally followed 256 community-living older adults (age: 76.4±4.5 yrs; 61% women) who were dementia free and had good mobility upon entrance into the study. At baseline, a computerized cognitive battery generated an index of EF, attention, a closely related construct, and other cognitive domains. Gait was assessed during single and dual task conditions. Falls data were collected prospectively using monthly calendars. Negative binomial regression quantified risk ratios (RR). After adjusting for age, gender and the number of falls in the year prior to the study, only the EF index (RR: .85; CI: .74–.98, p = .021), the attention index (RR: .84; CI: .75–.94, p = .002) and dual tasking gait variability (RR: 1.11; CI: 1.01–1.23; p = .027) were associated with future fall risk. Other cognitive function measures were not related to falls. Survival analyses indicated that subjects with the lowest EF scores were more likely to fall sooner and more likely to experience multiple falls during the 66 months of follow-up (p<0.02). Conclusions/Significance These findings demonstrate that among community-living older adults, the risk of future falls was predicted by performance on EF and attention tests conducted 5 years earlier. The present results link falls among older adults to cognition, indicating that screening EF will likely enhance fall risk assessment, and that treatment of EF may reduce fall risk.

Does the Evaluation of Gait Quality During Daily Life Provide Insight Into Fall Risk? A Novel Approach Using 3-Day Accelerometer Recordings

Background. Many approaches are used to evaluate fall risk. While their properties and performance vary, most reflect performance at a specific moment or are based on subjective self-report. Objective. To quantify fall risk in the home setting using an accelerometer. Methods. Seventy-one community-living older adults were studied. In the laboratory, fall risk was assessed using performance-based tests of mobility (eg, Timed Up and Go) and usual walking abilities were quantified. Subsequently, subjects wore a triaxial accelerometer on their lower back for 3 consecutive days. Acceleration-derived measures were extracted from segments that reflected ambulation. These included total activity duration, number of steps taken, and the amplitude and width at the dominant frequency in the power spectral density, that is, parameters reflecting step-to-step variability. Afterwards, self-report of falls was collected for 6 months to explore the predictive value. Results. Based on a history of 2 or more falls, subjects were classified as fallers or nonfallers. The number of steps during the 3 days was similar (P = .42) in the fallers (7842.1 ± 6135.6) and nonfallers (9055.3 ± 6444.7). Compared with the nonfallers, step-to-step consistency was lower in the fallers in the vertical axis (amplitude fallers, 0.58 ± 0.22 psd; nonfallers, 0.71 ± 0.18 psd; P = .008); in the mediolateral axis, step-to-step consistency was higher in the fallers (P = .014). The 3-day measures improved the identification of past and future falls status (P < .005), compared to performance-based tests. Conclusions. Accelerometer-derived measures based on 3-day recordings are useful for evaluating fall risk as older adults perform daily living activities in their everyday home environment.

Dual-Task Training on a Treadmill to Improve Gait and Cognitive Function in Elderly Idiopathic Fallers

Background and Purpose: Daily activities require the ability to dual task (DT), utilizing cognitive resources while walking to negotiate complex environmental conditions. For older adults, these additional cognitive demands often lead to reduced gait quality that increases the risk of falls. The aim of this study was to assess whether a combined intervention, consisting of treadmill training (TT) while performing DT, improves cognitive and motor performance in older adults with a history of multiple falls. Methods: A repeated measures design was used to evaluate the effects of training in 10 elderly fallers (mean age, 78.1 ± 5.81 y, 7 women). The progressive intensive training sessions included walking on a treadmill while practicing a variety of dual tasks 3 times a week for more than 6 weeks. Cognitive and motor measures were used to assess the effects of the intervention immediately after training and 1 month posttraining. Results: Improvements were observed in Berg Balance Scale (P = 0.02), Dynamic Gait Index (P = 0.03), gait speed during usual walking and while DT (P < 0.05), and cognitive performance as measured by the Trails Making Test B (P = 0.02). Furthermore, quality of life improved (SF-36: P = 0.01) as did physical activity (Physical Activity Scale for Elderly: P = 0.02). At 1 month postintervention, changes were not significant. Discussion and Conclusions: After 6 weeks of TT + DT program, elderly fallers demonstrated improved scores on tests of mobility, functional performance tasks, and cognition. Dual task training can be readily implemented by therapists as a component of a fall-risk reduction training program. Video Abstract available. See Video (Supplemental Digital Content 1, http://links.lww.com/JNPT/A81) for more insights from the authors.

GaitAssist: A wearable assistant for gait training and rehabilitation in Parkinson's disease

Many patients with Parkinsons disease suffer from short periods during which they cannot continue walking, the so-called freezing of gait. Patients can learn to use rhythmic auditory sounds as support during these episodes. We developed GaitAssist, a personalized wearable system for freezing of gait support, that enables training in unsupervised environments. GaitAssist detects freezing episodes from ankle-mounted motion sensors, which stream data via Bluetooth to an Android phone. In response, the system plays a rhythmic auditory sound that adapts to the patients regular gait speed. While GaitAssist can be used as a daily-life assistant, it also provides support for three types of training and rehabilitation exercises. The user can create personalized training sessions by adjusting the exercise and feedback parameters.

A Wearable Assistant for Gait Training for Parkinson’s Disease with Freezing of Gait in Out-of-the-Lab Environments

People with Parkinson’s disease (PD) suffer from declining mobility capabilities, which cause a prevalent risk of falling. Commonly, short periods of motor blocks occur during walking, known as freezing of gait (FoG). To slow the progressive decline of motor abilities, people with PD usually undertake stationary motor-training exercises in the clinics or supervised by physiotherapists. We present a wearable system for the support of people with PD and FoG. The system is designed for independent use. It enables motor training and gait assistance at home and other unsupervised environments. The system consists of three components. First, FoG episodes are detected in real time using wearable inertial sensors and a smartphone as the processing unit. Second, a feedback mechanism triggers a rhythmic auditory signal to the user to alleviate freeze episodes in an assistive mode. Third, the smartphone-based application features support for training exercises. Moreover, the system allows unobtrusive and long-term monitoring of the user’s clinical condition by transmitting sensing data and statistics to a telemedicine service. We investigate the at-home acceptance of the wearable system in a study with nine PD subjects. Participants deployed and used the system on their own, without any clinical support, at their homes during three protocol sessions in 1 week. Users’ feedback suggests an overall positive attitude toward adopting and using the system in their daily life, indicating that the system supports them in improving their gait. Further, in a data-driven analysis with sensing data from five participants, we study whether there is an observable effect on the gait during use of the system. In three out of five subjects, we observed a decrease in FoG duration distributions over the protocol days during gait-training exercises. Moreover, sensing data-driven analysis shows a decrease in FoG duration and FoG number in four out of five participants when they use the system as a gait-assistive tool during normal daily life activities at home.

Clinical Experience Using a 5-Week Treadmill Training Program With Virtual Reality to Enhance Gait in an Ambulatory Physical Therapy Service

Background Current literature views safe gait as a complex task, relying on motor and cognitive resources. The use of virtual reality (VR) in gait training offers a multifactorial approach, showing positive effects on mobility, balance, and fall risk in elderly people and individuals with neurological disorders. This form of training has been described as a viable research tool; however, it has not been applied routinely in clinical practice. Recently, VR was used to develop an adjunct training method for use by physical therapists in an ambulatory clinical setting. Objective The aim of this article is to describe the initial clinical experience of applying a 5-week VR clinical service to improve gait and mobility in people with a history of falls, poor mobility, or postural instability. Design A retrospective data analysis was conducted. Methods The clinical records of the first 60 patients who completed the VR gait training program were examined. Training was provided 3 times per week for 5 weeks, with each session lasting approximately 1 hour and consisting of walking on a treadmill while negotiating virtual obstacles. Main outcome measures were compared across time and included the Timed “Up & Go” Test (TUG), the Two-Minute Walk Test (2MWT), and the Four Square Step Test (FSST). Results After 5 weeks of training, time to complete the TUG decreased by 10.3%, the distance walked during the 2MWT increased by 9.5%, and performance on the FSST improved by 13%. Limitations Limitations of the study include the use of a retrospective analysis with no control group and the lack of objective cognitive assessment. Conclusions Treadmill training with VR appears to be an effective and practical tool that can be applied in an outpatient physical therapy clinic. This training apparently leads to improvements in gait, mobility, and postural control. It, perhaps, also may augment cognitive and functional aspects.

Clinical experience using a 5 week treadmill training program with virtual reality to enhance gait

Gait disorders and their resultant adverse effects are a major health problem. The aim of this retrospective analysis was to explore the efficacy of a 5-week VR clinical service to improve gait and mobility in subjects with a history of falls, mobility or stability dysfunction. 60 subjects received 15 sessions (3/week) of progressive intensive treadmill training while negotiating virtual obstacles. Significant improvements were observed in performance-based measures and endurance after completing the program. Treadmill training with VR appear to be an effective clinical tool. As a combined approach, this training may lead to further improvements in cognitive and functional aspects.

Gait Disorders in Patients with Cognitive Impairment or Dementia

Cognitive impairment and dementia are common in aging. In recent years, there is a growing body of evidence that suggests that gait is reliant on cognitive function and that gait impairments and falls are affected by a wide spectrum of age-associated changes in cognitive function. Several studies have suggested that gait abnormalities can already be present in the early stages of cognitive decline, even before dementia has been diagnosed. In this chapter, we describe the relationship between gait and cognition as a function of the severity of cognitive decline. We begin with a review of the current understanding of age-associated changes in both cognition and motor function and the interrelation between these domains in older adults. We then review reports on gait changes in mild cognitive impairment, dementia, and Alzheimer’s disease dementia, as well as alterations of motor function throughout the course of cognitive decline. Finally, we summarize information on therapeutic interventions designed to improve gait and reduce fall risk based on the interactions between gait and cognitive function.