Background
The prevalence of balance and gait deficits increases with age and is associated with the increased incidence of falls seen in the elderly population; these falls are associated with ...significant morbidity and mortality.
Objectives
To review changes in gait and balance associated with aging and the effect of visual perturbations on gait and balance in the elderly to provide a basis for future research.
Methods
PubMed and Cochrane Library were searched for articles from 1980 to present pertaining to gait and balance in older adults (>60) and younger adults (<60). Search terms included balance, posture, gait, locomotion, gait variability, gait disorders, gait disturbance, elderly, aging, falls, vision, visual, vestibular, and virtual reality. The references section of queried articles was also used to find relevant studies. Studies were excluded if subjects had a diagnosed gait or balance disorder.
Results
Elderly adults show age‐related decline in sensory systems and reduced ability to adapt to changes in their environment to maintain balance. Elderly adults are particularly dependent on vision to maintain postural stability. Distinct changes in spatiotemporal gait parameters are associated with aging, such as slower gait and increased gait variability, which are amplified with exposure to visual perturbations. Increased gait variability, specifically with mediolateral perturbations, poses a particular challenge for elderly adults and is linked to increased falls risk. Virtual reality training has shown promising effects on balance and gait.
Conclusion
Elderly adults show age‐related decline in balance and gait with increased gait variability and an associated increased risk of falls.
Level of Evidence
5
Instrumented footwear represents a promising technology for spatiotemporal gait analysis in out-of-the-lab conditions. However, moderate accuracy impacts this technology's ability to capture subtle, ...but clinically meaningful, changes in gait patterns that may indicate adverse outcomes or underlying neurological conditions. This limitation hampers the use of instrumented footwear to aid functional assessments and clinical decision making. This paper introduces new transductive-learning inference models that substantially reduce measurement errors relative to conventional data processing techniques, without requiring subject-specific labelled data. The proposed models use subject-optimized input features and hyperparameters to adjust the spatiotemporal gait metrics (i.e., stride time, length, and velocity, swing time, and double support time) obtained with conventional techniques, resulting in computationally simpler models compared to end-to-end machine learning approaches. Model validity and reliability were evaluated against a gold-standard electronic walkway during a clinical gait performance test (6-minute walk test) administered to N = 95 senior residents of assisted living facilities with diverse levels of gait and balance impairments. Average reductions in absolute errors relative to conventional techniques were −42.0% and −33.5% for spatial and gait-phase parameters, respectively, indicating the potential of transductive learning models for improving the accuracy of instrumented footwear for ambulatory gait analysis.
In the past decade, an increasing number of studies have examined the efficacy of physical therapy interventions in people with Huntington disease (HD).
We performed a mixed-methods systematic review ...using Joanna Briggs Institute (JBI) methodology and included experimental and observational study designs. The search resulted in 23 quantitative studies and 3 qualitative studies from which we extracted data using JBI standardized extraction tools. Results of this review suggested that physical therapy interventions may improve motor impairments and activity limitations in people with HD. Here, we expand on the review findings to provide specific recommendations to guide clinical practice.
We recommend the following specific physical therapy interventions for people with HD: aerobic exercise (grade A evidence), alone or in combination with resistance training to improve fitness and motor function, and supervised gait training (grade A evidence) to improve spatiotemporal features of gait. In addition, there is weak (grade B) evidence that exercise training improves balance but does not show a reduction in the frequency of falls; inspiratory and expiratory training improves breathing function and capacity; and training of transfers, getting up from the floor, and providing strategies to caregivers for involvement in physical activity in the midstages of HD may improve performance. There is expert consensus for the use of positioning devices, seating adaptations, and caregiver training in late stages of HD.
There is strong evidence to support physical therapy interventions to improve fitness, motor function, and gait in persons with HD.
Biofeedback systems have been extensively used in walking exercises for gait improvement. Past research has focused on modulating the wearer's cadence, gait variability, or symmetry, but none of the ...previous works has addressed the problem of inducing a desired walking speed in the wearer. In this paper, we present a new, minimally obtrusive wearable biofeedback system (WBS) that uses closed-loop vibrotactile control to elicit desired changes in the wearer's walking speed, based on the predicted user response to anticipatory and delayed feedback. The performance of the proposed control was compared to conventional open-loop rhythmic vibrotactile stimulation with N = 10 healthy individuals who were asked to complete a set of walking tasks along an oval path. The closed-loop vibrotactile control consistently demonstrated better performance than the open-loop control in inducing desired changes in the wearer's walking speed, both with constant and with time-varying target walking speeds. Neither open-loop nor closed-loop stimuli affected natural gait significantly, when the target walking speed was set to the individual's preferred walking speed. Given the importance of walking speed as a summary indicator of health and physical performance, the closed-loop vibrotactile control can pave the way for new technology-enhanced protocols for gait rehabilitation.
Purpose of Review
The goal of this paper is to provide a review of recent work on the use of wearable devices for measuring physical activity (PA) in the elderly.
Recent Findings
In older adults, PA ...is related to independence in activities of daily living and maintaining a good quality of life. With aging, there is a reduction in PA, which may explain reduced energy expenditure (EE) during rest and PA. In addition, there is also a reduction in the spatial extent of mobility (life-space). Sensors used for measuring PA include pedometers, uni-axial, bi-axial and tri-axial accelerometers, heart rate monitors combined with accelerometers, and complex systems using multiple types of sensors.
Summary
Wearable sensors are accurate at measuring step counts, PA intensity, and EE, but need to improve accuracy of measuring type of PA, spatial extent of PA, and measuring non-ambulatory PA. Clear standards for measurement, algorithms used for computing clinically relevant measures, need to be developed.
OBJECTIVE. Alzheimer's disease (AD) results in a loss of independence in activities of daily living (ADLs), which in turn affects the quality of life of affected people and places a burden on ...caretakers. Limited research has examined the influence of physical training (aerobic, balance, and strength training) on ADL performance of people with AD. METHOD. Six randomized controlled trials (total of 446 participants) fit the inclusion criteria. For each study, we calculated effect sizes for primary and secondary outcomes. RESULTS. Average effect size (95% confidence interval) for exercise on the primary outcome (ADL performance) was 0.80 (p < .001). Exercise had a moderate impact on the secondary outcome of physical function (effect size = 0.53, p = .004). CONCLUSION. Occupational therapy intervention that includes aerobic and strengthening exercises may help improve independence in ADLs and improve physical performance in people with AD. Additional research is needed to identify specific components of intervention and optimal dosage to develop clinical guidelines.
Background. Impairments in postural control in Huntington disease (HD) have important consequences for daily functioning. This observational study systematically examined baseline postural control ...and the effect of sensory attenuation and sensory enhancement on postural control across the spectrum of HD. Methods. Participants (n = 39) included healthy controls and individuals in premanifest (pHD) and manifest stages (mHD) of HD. Using wearable sensors, postural control was assessed according to (1) postural set (sit vs stand), (2) sensory attenuation using clinical test of sensory integration, and (3) sensory enhancement with gaze fixation. Outcomes included sway smoothness, amplitude, and frequency. Results. Based on postural set, pHD reduced postural sway in sitting relative to standing, whereas mHD had pronounced sway in standing and sitting, highlighting a baseline postural deficit. During sensory attenuation, postural control in pHD deteriorated relative to controls when proprioceptive demands were high (eyes closed on foam), whereas mHD had significant deterioration of postural control when proprioception was attenuated (eyes open and closed on foam). Finally, gaze fixation improved sway smoothness, amplitude, and frequency in pHD; however, no benefit was observed in mHD. Conclusions. Systematic examination of postural control revealed a fundamental postural deficit in mHD, which further deteriorates when proprioception is challenged. Meanwhile, postural deficits in pHD are detectable when proprioceptive challenge is high. Sensory enhancing strategies using gaze fixation to benefit posture may be useful when introduced well before motor diagnosis. These findings encourage further examination of wearable sensors as part of routine clinical assessments in HD.
Filtering facepiece respirators (FFRs) provide effective protection against diseases spread through airborne infectious droplets and particles. The widespread use of FFRs during the COVID-19 pandemic ...has not only led to supply shortages, but the disposal of single-use facemasks also threatens the environment with a new kind of plastic pollution. While limited reuse of filtering facepiece respirators has been permitted as a crisis capacity strategy, there are currently no standard test methods available for decontamination before their repeated use. The decontamination of respirators can compromise the structural and functional integrity by reducing the filtration efficiency and breathability. Digital segmentation of X-ray microcomputed tomography (microCT) scans of the meltblown nonwoven layers of a specific N95 respirator model (Venus-4400) after treatment with one and five cycles of liquid hydrogen peroxide, ultraviolet radiation, moist heat, and aqueous soap solution enabled us to perform filtration simulations of decontaminated respirators. The computed filtration efficiencies for 0.3 µm particles agreed well with experimental measurements, and the distribution of particle penetration depths was correlated with the structural changes resulting from decontamination. The combination of X-ray microCT imaging with numerical simulations thus provides a strategy for quantitative evaluation of the effectiveness of decontamination treatments for a specific respirator model.
BackgroundWhile accumulating evidence suggests that balance and gait impairments are commonly seen in patients with essential tremor (ET), questions remain regarding their prevalence, their ...relationship with normal aging, whether they are similar to the impairments seen in spinocerebellar ataxias, their functional consequences, and whether some ET patients carry greater susceptibility. MethodsWe conducted a literature search (until December 2018) on this topic. ResultsWe identified 23 articles on gait or balance impairments in ET. The prevalence of balance impairment (missteps on tandem walk test) was seven times higher in ET patients than controls. Gait impairments in ET included reduced speed, increased asymmetry, and impaired dynamic balance. While balance and gait problems worsened with age, ET patients were more impaired than controls, independent of age. The pattern of impairments seen in ET was qualitatively similar to that seen in spinocerebellar ataxias. Balance and gait impairments resulted in greater number of near falls in ET patients. Factors associated with balance and gait impairments in ET included age, presence of tremor in midline structures, and cognitive dysfunction. DiscussionAccumulating evidence suggests that balance and gait impairments are common in ET patients and occur to a greater extent in controls. Thus, they represent a disease-associated feature. These impairments, which are qualitatively similar to those seen in spinocerebellar ataxias, are not merely subclinical but result in difficulty performing functional tasks and increase falls risk. A subset of patients is more susceptible to balance and gait impairments. The full spectrum of impairments remains to be characterized.
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