Circumstances and consequences of falls in independent community-dwelling older adults

Virtual obstacle-avoidance training using daily-life obstacles with physical feedback in older people: A cross-over trial

Failures in avoiding environmental hazards can lead to falls. We developed a virtual reality (VR) obstacle-avoidance training system that provides physical feedback upon foot contact with a virtual obstacle. This study aimed to assess whether physical feedback reduces obstacle collisions in older adults within a VR environment. Fifty-six participants (mean age 72.3 ± 5.4 (SD) years) wore an immersive VR head-mounted display and safety harness and walked on a split-belt treadmill in two 8-minute conditions performed in random order. They walked on a virtual suburban footpath, collecting virtual apples and avoiding slip-and-trip obstacles. In the perturbation condition (VR+P), foot-obstacle collisions were accompanied by immediate physical feedback via treadmill belt accelerations/decelerations. In the non-perturbation condition (VR-only), no physical feedback was provided. Obstacle collision rates and subjective acceptability were assessed. In the VR+P condition, participants had fewer obstacle collisions (0.63 versus 0.75), fewer trailing foot collisions (0.57 versus 0.68) and a greater margin of stability compared with the VR-only condition (p < 0.05). Participants reported significantly higher levels of anxiety and greater task difficulty for the VR+P condition (p < 0.05). Motion sickness was rarely reported, and enjoyment ratings were high, with no significant differences between the conditions. In summary, physical feedback reduced obstacle collisions and increased gait stability. The low levels of motion sickness and anxiety and high levels of enjoyment reported suggest that VR obstacle avoidance training is highly acceptable to older people. Future research is required to determine the generalisation of improved motor skills to real-world scenarios.

An Exploration of the Effects of Gait Speed and Joint Movements on Minimum Toe Clearance Across the Lifespan: A Cross-Sectional Study

The effect of gait speed on minimum toe clearance (MTC) amount may vary across the lifespan due to changes in joint relationships, potentially affecting trip-related fall risk in older adults. We evaluated whether age influences the relationship between gait speed and MTC amount, as well as between joint movements and MTC amount. Optical motion capture data was collected on 62 participants between the ages of 20 and 83 years during 25 gait trials at self-selected normal, fast, and slow speeds. Multilevel models were used for data analysis. Gait speed was associated with a 0.13 cm increase in MTC amount for every meter per second increase in gait speed with other factors constant and was unaffected by age. Ankle dorsi-plantarflexion, knee and hip flexion-extension, and stance hip abduction-adduction changed the MTC amount by 0.05, 0.02, 0.04, and 0.04 cm, respectively, for each degree of joint movement, with other factors constant, and was unaffected by age. Age did not affect the relationship between gait speed and MTC amount, nor the relationship of joint moments with MTC, indicating that these factors may not be associated with trip-related fall risk with healthy aging.

Proactive modifications to walking stability under the threat of large, anterior or posterior perturbations

Biomechanically, falling after a walking perturbation may be influenced by: (1) the pre-perturbation state of mechanical stability (e.g., stability margins) and (2) the response to a perturbation (i.e., recovery skill). Walking stability margins must be modifiable to serve as a target for fall-prevention interventions. We investigated if neurotypical adults could proactively modulate pre-perturbation anteroposterior stability margins while walking. Eleven adults walked on a treadmill at three speeds with and without anterior and posterior perturbations. We measured stability margins anteriorly at mid-swing and posteriorly at foot strike for pre-perturbation steps. A repeated-measures factorial ANOVA evaluated main effects and interactions of walking speed (0.6, 0.8, 1.0 stats/s) and perturbation type (anterior, none, posterior). With posterior perturbation threats, the posterior stability margins were more positive at foot strike (p < 0.01) compared to trials without perturbations. With anterior perturbation threats, the anterior stability margins were not different at mid-swing compared to trials without perturbations (p > 0.05). With any perturbation threat, step lengths shortened (p < 0.01) and step rates increased (p < 0.01). Step width was not different (p > 0.11). At slow speeds with posterior perturbation threats, double-support time decreased (p = 0.04). Proactive modifications to stability margins are indeed possible in a neurotypical population. Consequently, anteroposterior stability margins may be a feasible target for fall-prevention interventions by targeting decreased step lengths or increased step rates within a given walking speed. We do not know the extent to which the observed effects have a meaningful effect on perturbation recovery.

Effect of Soft Surface Stepping Exercise on Physical Activity Among Community-Dwelling Elderly: A Prospective Randomized Controlled Trial

Objective

To investigate the effects of modified stepping exercises over six weeks on functional mobility and individual lower extremity muscle strength in community-dwelling older individuals.

METHODS

This prospective randomized controlled trial design was conducted in thirty-two older adults who completed a modified stepping exercises program (n=16 for soft-surface stepping exercise; n=16 for firm-surface stepping exercise). These exercises were practiced for 50 minutes/day, three days/week, over six weeks. They were assessed for their functional mobility relating to levels of independence at baseline, after 4 weeks, after 6 weeks of intervention, and at 1 month after the last intervention sessions.

RESULTS

Both groups showed significant improvements in functional mobility, lower extremity muscle strength, and walking speed after 4 and 6 weeks of intervention, as well as at the one-month follow-up. However, the soft-surface stepping exercise group exhibited significantly greater improvements in dynamic balance (p=0.035) and lower extremity muscle strength (p=0.015) compared to the firm-surface stepping exercise group after 6 weeks of intervention. Additionally, the soft-surface group demonstrated superior gains in hip flexor (p=0.041), hip extensor (p=0.047), hip adductor (p=0.026), and hip abductor strength (p=0.046), with these enhancements maintained at the one-month follow-up.

Conclusion

Soft-surface stepping exercise that involves whole-body movements offers a promising alternative to promote independence and safety among community-dwelling older adults. This study underscores the need for future research to evaluate the sustained impact of these benefits post-intervention, particularly during a retention period following the intervention.

Correlates of gait speed changes during uneven terrain walking in older adults: differential roles of cognitive and sensorimotor function

Many studies of walking function and aging have measured walking on flat surfaces with and without dual-tasking (i.e., performing a concurrent cognitive task). Walking in the community increases the complexity with surface undulations and varying surface types. We hypothesized that changes in walking resulting from increasing terrain unevenness would be better predicted by sensorimotor function than cognitive function. Sixty-three community-dwelling older adults (65-93 yrs old; 32 males) performed overground walking under four uneven terrain conditions (Flat, Low, Medium, and High unevenness). Cognitive (cognitive flexibility, working memory, inhibition) and sensorimotor assessments (grip strength, 2-pt discrimination, pressure pain threshold) were measured as the primary predictors of walking performance. We found that walking speed decreased linearly with more elevated uneven terrain conditions across all participants; this was accentuated in older adults with lower mobility function. Greater rates of decline in walking speed from flat to uneven terrain were associated with worse attention and inhibitory function as well as lower 2-point tactile discrimination. Findings suggest that greater rates of decline with elevated terrain walking are associated with lower mobility function, lower executive functions and less somatosensation.

The effects of perturbation intensities on backward slip-falls induced by a split-belt treadmill

Fall-inducing systems have two critical applications. One is to obtain the biomechanical features of falling, and the other is to systematically train individuals and reduce the risk of falling. While the former application necessitates the occurrence of falls, the latter does not require fall-inducing perturbations to be excessively intense. The purposes of the study were to investigate the effects of perturbation intensities (a combination of speeds and durations) on the number of falls, fall rates, and maximum loading forces resulting from slips induced by a split-belt treadmill. Twenty-four young adults (12 males and 12 females) completed 16 randomized trials (12 perturbation trials and 4 false trials). The forces between a safety harness and a rail were used to identify falls and non-falls and to assess the maximum loading force during falls. Although the number of falls, fall rates, and maximum loading force significantly increase as the slipping speed increases for both durations, the relative risk analysis shows that fall risk significantly increases as the slipping speed increases regardless of the duration. These findings may contribute to developing design criteria for controlled perturbations using a split-belt treadmill, aimed at enhancing our understanding of fall biomechanics and informing fall prevention training programs.

Effects of Twelve Weeks of Square Stepping Exercises on Physical and Cognitive Function and Plasma Content of SMP30: A Randomised Control Trial

BACKGROUND

Ageing and sedentary lifestyles affect physical and cognitive function and markers of frailty, increasing the risk of falls in older adults and affecting their quality of life. The aim of this study was to evaluate the effects of a Square Step Exercise programme on physical and cognitive function and plasma SMP30 levels for the prevention of falls in older adults.

METHODS

A randomised controlled trial was designed with 44 participants assigned to an experimental group (SSE group) and a control group. The SSE group performed SSE sessions twice a week for three months, with a follow-up in the fourth month. The assessments of physical function included tests such as the Four-Square Step Test, Brisk Walking and its dual-task variant, Time Up and Go and its imagined and dual-task variants, 30 s Sit-to-Stand and its dual-task and imagined variants and a 6 min walking test. Questionnaires were also used to assess the risk and fear of falling. Resting EEG activity was also recorded to assess electrocortical brain activity. SMP30 levels were measured by Western blotting.

RESULTS

The SSE group showed significant improvements compared to the control group in the Four-Square Step Test (p < 0.001), Brisk Walking (p < 0.05) and reduction in the fear of falling (p < 0.001) after the training programme, but these adaptations were not maintained one month after the programme ended (p < 0.05). No significant changes were observed in the remaining variables of physical function, cognitive function, fall risk questionnaire, EEG activity or plasma levels of SMP30 compared to the control group (p > 0.05).

CONCLUSIONS

The SSE programme showed efficacy in improving balance, gait speed and reducing fear of falling in older adults but did not show improvement over the control group in other areas of physical or cognitive function or plasma SMP30 levels for fall prevention.

Sternum drop as a kinematic measure of trip recovery performance

Deficient trip recovery kinematics have been implicated in many trip-induced falls. Three key requisites for successful trip recovery include limiting trunk flexion, maintaining adequate hip height to enable repeated stepping, and completing recovery steps to extend the base of support. The purpose of this study was to evaluate sternum drop as a new measure of trip recovery performance. Sternum drop may be a more robust than other measures of trip recovery performance because, unlike other common trip recovery measures, it is sensitive to two of the three trip recovery requisites. Thirty community-dwelling older adults were exposed to two laboratory-induced trips while walking on a walkway. Sternum drop was determined using two separate methods: from optoelectronic motion capture and an inertial measurement unit. For comparison sternum drop, trunk angle and hip height, both at touchdown of the first recovery step, were also determined. Sternum drop from optoelectronic motion capture exhibited strong correlation with trunk angle at touchdown (repeated-measures correlation coefficient (rrm) = 0.94; p < 0.001), strong correlation with hip height at touchdown (rrm = -0.90; p < 0.001), and strong correlation with sternum drop from IMU (rrm = 0.95; p < 0.001). In addition, sternum drop from optoelectronic motion capture (p < 0.001) and sternum drop from inertial measurement unit (p = 0.001) differed between falls and recoveries, with the former exhibiting the largest effect size (partial eta2 = 0.36) between falls and recoveries. These results support sternum drop as a valid kinematic measure of trip recovery performance.

Empowering Fall Prevention Through Integrated Lifestyle Medicine Strategies-From Recognition of Fall Risks to Implementation of Prevention of Falls for all in Practice

Falls remain the leading cause of unintentional injuries across all age groups, prompting many emergency room visits. The annual estimated cost associated with falls is believed to exceed 100 billion dollars. In addressing this trend, health professional team members emerge as key players and can assume a crucial role in bridging the gap between lifestyle medicine and fall prevention. By imparting strategies aligned with the 6 pillars of lifestyle medicine, these professionals can educate individuals on risk factors, assess fall risk, and offer activities to mitigate the likelihood of future falls. This collaborative approach empowers all to take immediate and informed action, fostering a proactive stance against the prevalent issue of fall-related injuries. Through the background and practical strategies described in this paper, health professionals of various disciplines will have access to tools and knowledge to enhance their role in preventing falls using the lens of lifestyle medicine.

Reducing trailing limb collisions in older adults through targeted leading limb placement after obstacle crossing: effect of closer foot placement

Introduction

Older adults experience a higher frequency of collisions with obstacles when stepping over obstacles, particularly with the trailing limb. We recently demonstrated that placing the leading limb closer to an obstacle after crossing effectively increases the toe height of the trailing limb, resulting in reduced collision. This study investigated whether the intervention of placing the leading limb closer to the obstacle is effective in reducing trailing limb collisions in healthy older adults.

Methods

Twenty-one older individuals (11 males, 10 females; mean age 75.7 years) participated. Participants were allocated to one of two groups: a closer placement group, instructed to place the leading limb on a square target positioned on their walking path after crossing an obstacle, and a control group, instructed to cross the obstacle naturally. The target in the closer group was set at 0.5 times the leading limb's foot placement distance, as determined in a pre-test for each participant. The experimental design included a pre-test, intervention, and post-test.

Results and discussion

The collision rate for the trailing limb in the closer group was significantly lower in the post-test than that in the pre-test. Furthermore, the variability in toe height and walking speed of the trailing limb in the closer group decreased significantly in the post-test compared to the pre-test. These findings suggest that the intervention of placing the leading limb foot closer to the obstacle after crossing may improve obstacle avoidance by the trailing limb in healthy older adults.

Treadmill belt accelerations may not accurately replicate kinematic responses to tripping on an obstacle in older people

BACKGROUND

Treadmill belt perturbations have high clinical feasibility for use in perturbation-based training in older people, but their kinematic validity is unclear. This study examined the kinematic validity of treadmill belt accelerations as a surrogate for overground walkway trips during gait in older people.

METHODS

Thirty-eight community-dwelling older people were exposed to two unilateral belt accelerations (8 m s-2) whilst walking on a split-belt treadmill and two trips induced by a 14 cm trip-board whilst walking on a walkway with condition presentation randomised. Anteroposterior margin of stability (MoS), number of falls, and trunk and lower limb kinematics were quantified for the step prior and five recovery steps following the treadmill perturbations and the walkway trips which elicited elevating and lowering strategies.

FINDINGS

Rates of falls following the treadmill accelerations and walkway trips were 0% and 13.1%, respectively. MoS was similar during the first recovery step (P>0.05) but less negative during subsequent recovery steps following treadmill belt accelerations than walkway trips (P<0.01) regardless of recovery strategy. Excluding the first recovery step in the lowering strategy, recovery step lengths, toe clearance, maximum trunk, hip and knee angles (P<0.05) were smaller during recovery on the treadmill compared to the walkway.

INTERPRETATION

Destabilisation by treadmill belt accelerations quickly dissipated after only one recovery step but continued for multiple recovery steps following walkway trips. Smaller trunk displacement, step lengths, toe clearance and no falls on the treadmill indicate treadmill belt accelerations may not accurately simulate the biomechanical challenge of obstacle-induced trips in older people.

Relationship between typical fall patterns and fall-related fractures in older Japanese adults

This study explored the relationship between fall patterns and fall-related fractures in older adults. A cross-sectional survey was conducted among community-dwelling older adults in Maibara City, Japan, focusing on falls over the past three years. Among the 1,695 reported falls, 176 fractures occurred in 120 individuals. Backward or straight-down and sideways falls were more likely to result in fractures compared to forward falls, with odds ratios (95％ confidence interval) of 3.23 (2.08-5.02) and 3.68 (2.35-5.76), respectively. Falls triggered by slipping or loss of balance had higher fracture rates than those triggered by tripping. Specific fall patterns were associated with particular fractures, such as forearm and patella fractures from forward falls, spine fractures from backward or straight-down falls, and hip fractures from sideways falls. We conclude that the fracture risk varies significantly based on fall patterns, providing insights for enhancing fall prevention strategies.

Wrist-worn voice recorders capture the circumstances and context of losses of balance among community-dwelling older adults

BACKGROUND

Most falls among community-dwelling older adults are due to a loss of balance (LOB) after tripping or slipping. Unfortunately, limited insight is available on the detailed circumstances and context of these LOBs. Moreover, commonly used methods to collect this information is susceptible to limitations of memory recall. The goal of this pilot observational study was to explore the circumstances and context of self-reported LOBs captured by wrist-worn voice recorders among community-dwelling older adults.

METHODS

In this pilot observational cohort study, 30 community-dwelling adults with a mean (SD) age of 71.8 (4.4) years were asked to wear a voice recorder on their wrist daily for 3 weeks. Following any naturally-occurring LOB, participants were asked to record their verbal responses to six questions regarding the circumstances and context of each LOB abbreviated with the mnemonic 4WHO: When, Where, What, Why, How, and Outcome.

RESULTS

Participants wore the voice recorder 10.9 (0.6) hours per day for 20.7 (0.5) days. One hundred seventy-five voice recordings were collected, with 122 meeting our definition of a LOB. Each participant reported 0-23 LOBs over the 3 weeks or 1.4 (2.1) per participant per week. Across all participants, LOBs were most commonly reported 3 p.m. or later (42%), inside the home (39%), while walking (33%), resulting from a trip (54%), and having induced a stepping response to regain balance (48%). No LOBs resulted in a fall.

CONCLUSIONS

Among community-dwelling older adults, wrist-worn voice recorders capture the circumstances and context of LOBs thereby facilitating the documentation of detail of LOBs and potentially falls, without reliance on later recall.

Inertial measurement units worn on the dorsum of the foot and proximal to the ankle can provide valid slip recovery measures

BACKGROUND

Slips are a leading cause of injury among older adults. Slip recovery measures are often captured using optoelectronic motion capture (OMC) systems that can be costly and typically require a laboratory setting. Inertial measurement unit (IMU) systems show promise as a lower cost, portable, and wearable form of motion capture.

QUESTION

Can IMUs worn on the dorsum of the feet and proximal to the ankles be used to capture valid slip recovery measures?

METHODS

Thirty older adults (ages 65-80; 18 females) were exposed to a laboratory slip while wearing OMC markers, IMUs on the dorsum of the feet, and IMUs proximal to the ankles. To evaluate the concurrent validity of IMU-based slip recovery measures using the OMC-based measures as our standard, we determined whether the IMU-based slip recovery measures differed between falls and recoveries, and evaluated the strength of correlation between IMU-based measures and OMC. We also defined the difference between foot IMU-based and OMC-based slip recovery measures to be the system offset, and compared the system offset variance between participant-placed IMUs and researcher-placed IMUs.

RESULTS

All IMU-based and OMC-based slip recovery measures differed between falls and recoveries (p ≤ 0.008), and all IMU-based measures exhibited strong correlation (r ≥ 0.94) with OMC-based measures. The system offset variance was larger when foot IMUs were participant-placed than when researcher-placed for anterior-posterior slip distance (p = 0.032), but not other slip recovery measures (p ≥ 0.054).

SIGNIFICANCE

IMUs worn on the dorsum of the feet and proximal to the ankle can provide valid slip recovery measures in a laboratory setting. This includes IMUs placed by participants on the dorsum of the feet that might be needed for the long-term monitoring of these measures by participants outside the laboratory setting.

Environmental constraints for improving motor flexibility during obstacle crossing in older adults

BACKGROUND

An age-related decline in motor flexibility, which is the ability to synergistically control the degrees of freedom of the body to ensure stable performance of a task, is a factor that contributes to falls. We investigated whether providing environmental constraints to increase the movement repertoire (i.e., the motor solution that works to achieve one's goal), in combination with aiming at precise control of the performance, would be effective for improving motor flexibility, and whether the effect on the leading limb would extend to the trailing limb.

METHODS

Fifteen older adults (75.1 ± 6.2 years and 14 younger adults (34.6 ± 5.0 years) performed under three walking conditions: walking normally and crossing the obstacle (normal), walking and crossing the obstacle with constraints of foot placement after stepping over it (constrained), and walking and crossing the obstacle with constraints as in the constrained condition, in addition to aiming for maintaining a constant clearance height at the moment of obstacle crossing (precision). An uncontrolled manifold analysis was used to quantify motor flexibility as the synergy index. The foot height at the moment of obstacle crossing was used as the performance variable and seven segmental angles were used as the elemental variables. A higher synergy index indicates greater motor flexibility.

RESULTS

For the leading limb, the synergy index was significantly higher under the precision condition than those under the other conditions. This suggests that not only providing environmental constraints but also keeping constant the performance variable is critical to improving motor flexibility. Moreover, the effects of an increase in the synergy index in the leading limb extended to the trailing limb.

CONCLUSIONS

Providing environmental constraints to increase the movement repertoire while also aiming for precision in the performance variable was an effective method of improving motor flexibility during obstacle crossing for older adults.

Reliability and Validity of Four Step Tests in Older Adults With Dementia

OBJECTIVES

To determine the test-retest and inter-rater reliability, concurrent and discriminative validity of the Four Square Step Test (FSST), the Choice Stepping Reaction Time Test (CSRTT), the Maximum Step Length Test (MSLT), and the Alternate Step Test (AST) in older adults with dementia.

METHODS

Thirty-seven older adults with dementia who could walk independently for at least 10 m were recruited at community centers and day care centers for older adults. The participants completed the step tests conducted by two independent raters on three separate testing occasions within 3 weeks. In addition, the physical and cognitive function of the participants were evaluated at baseline.

RESULTS

The FSST, CSRTT, and MSLT showed good-to-excellent test-retest reliability (intraclass correlation coefficient [ICC] = 0.83-0.91), and the AST exhibited fair test-retest reliability (ICC = 0.70). All the step tests showed good-to-excellent inter-rater reliability (ICC = 0.75-0.94). The step tests had moderate-to-strong correlations with various physical and cognitive measures (Pearson correlation coefficients = 0.34-0.72). The MSLT side step and AST could differentiate between individuals who did and did not use a walking stick to ambulate (p ≤ 0.046). The FSST, CSRTT, and AST could differentiate between individuals with and without a major neurocognitive impairment (p ≤ 0.005).

CONCLUSION

The FSST, CSRTT, and MSLT were reliable and valid for examining the stepping performance of older adults with dementia. Clinicians can use these tests to evaluate the physical and cognitive function of this population and identify those with significant cognitive impairment.

TRIAL REGISTRATION

Clinical Trial Registration number: NCT04296123.

Design and Validation of a Tripping-Eliciting Platform Based on Compliant Random Obstacles

Goal: The experimental study of the stumble phenomena is essential to develop novel technological solutions to limit harmful effects in at-risk populations. A versatile platform to deliver realistic and unanticipated tripping perturbations, controllable in their strength and timing, would be beneficial for this field of study. Methods: We built a modular tripping-eliciting system based on multiple compliant trip blocks that deliver unanticipated tripping perturbations. The system was validated with a study with 9 healthy subjects. Results: The system delivered 33 out of 34 perturbations (a minimum of 3 per subject) during the desired gait phase, and 31 effectively induced a tripping event. The recovery strategies adopted after the perturbations were qualitatively consistent with the literature. The analysis of the inertial motion unit signals and the questionnaires suggests a limited adaptation to the perturbation throughout experiments. Conclusions: The platform succeeded in providing realistic trip perturbations, concurrently limiting subjects' adaptation. The presence of multiple compliant obstacles, tunable regarding position and perturbation strength, represents a novelty in the field, allowing the study of stumbling phenomena caused by obstacles with different levels of sturdiness. The overall system is modular and can be easily adapted for different applications.

Towards a comprehensive framework for complex walking tasks: Characterization, behavioral adaptations, and clinical implications in ageing and neurological populations

Complex walking tasks, including change of direction, patterns and rhythms, require more attentional resources than simple walking and significantly impact walking performance, especially among ageing and neurological populations. More studies have been focusing on complex walking situations, with or without the addition of cognitive tasks, creating a multitude of walking situations. Given the lack of a clear and extensive definition of complex walking, this narrative review aims to identify and more precisely characterize situations and related tests, improve understanding of behavioral adaptations in ageing and neurological populations, and report the clinical applications of complex walking. Based on the studies collected, we are proposing a framework that categorizes the different forms of complex walking, considering whether a cognitive task is added or not, as well as the number of distinct objectives within a given situation. We observed that combining complex walking tasks with a cognitive assignment places even greater strain on attentional resources, resulting in a more pronounced decline in walking and/or cognitive performance. This work highlights the relevance of complex walking as a simple tool for early detection of cognitive impairments and risk of falls, and its potential value in cognitive-motor rehabilitation. Future studies should explore various complex walking tasks in ageing and neurological populations, under varied conditions in real-life or in extended virtual environments.

Characteristics of falls in Japanese community-dwelling older adults

OBJECTIVE

Understanding the characteristics of falls among older adults is necessary to prevent them. These characteristics include questions such as when (month and time), where (places), who (age), what (injury), why (trigger), and how (direction) the falls occur. The objective of this study was to identify the characteristics of falls in individuals aged 65-74 years (young-old), 75-84 years (old-old), and ≥85 years (oldest-old).

METHODS

We conducted an observational mail survey among community-dwelling older adults in Japan and collected detailed information on the incidence of falls over the past 3 years. The month, time, location, trigger, direction, and resulting trauma of each fall were analyzed and compared across the different age groups (young-old, old-old, and oldest-old).

RESULTS

A total of 1695 falls among 1074 community-dwelling older adults were analyzed in this study. Falls were frequent during May and October as well as during the winter season from December to February, especially between 10:00 a.m. and 11:00 a.m. These fall characteristics were consistent across all the age groups. There was a higher incidence of outdoor falls among relatively young older adults, which were typically caused by tripping or slipping. However, as one progresses with age, there is a higher incidence of falls indoors, typically due to loss of balance or leg entrapment. Approximately 60% of older fallers experience some form of injury due to falls, with fractures considered the most serious, occurring in ≈10% of all falls.

CONCLUSION

We clarified the characteristics of falls including the "when, where, who, what, why, and how" of the fall. A future challenge is to use this valuable information to develop effective fall prevention programs for older populations worldwide. Geriatr Gerontol Int 2024; 24: 1181-1188.

The Stepping Threshold Test for assessing reactive balance discriminates between older adult fallers and non-fallers

Introduction

The ability to respond effectively to external perturbations is crucial for avoiding falls. The Stepping Threshold Test (STT) has been developed to assess this reactive balance, but its ability to discriminate between fallers and non-fallers is still unsubstantiated. This study aimed to evaluate the discriminant validity of the STT in distinguishing fallers and non-fallers and its convergent validity.

Methods

Thirty-six older adults (age = 80 ± 5 years), with 13 (36%) of them reporting a fall history in the past year, completed the STT on a perturbation treadmill. They received surface perturbations of progressively increasing magnitude while standing. Single- and multiple-step thresholds were assessed using an all-step count evaluation (STT-ACE), and a direction-sensitive evaluation strategy (STT-DSE). Receiver operating characteristics and area under the curves (AUC) were analyzed to evaluate the discriminative accuracy. Convergent validity was explored by 13 hypothesized associations with other mobility, psychological, and cognitive assessments.

Results

Fallers and non-fallers significantly differed in the STT-DSE (p = 0.033), but not in the STT-ACE or other commonly used mobility assessments. Acceptable discriminative accuracy was obtained for the STT-DSE (AUC = 0.72), but not for the STT-ACE and other mobility assessments (AUC = 0.53-0.68). Twelve (92%) associations were consistent with our hypotheses for the STT-DSE, and ten (77%) for the STT-ACE.

Conclusion

Our findings provide preliminary evidence that the STT, when using the STT-DSE, may discriminate between older adult fallers and non-fallers. The STT appears to be a valid tool for assessing reactive balance, with its STT-DSE being recommended due to its better discriminant and convergent validity compared to the STT-ACE.

Frictional Performance of Geometrically Modified Footwear Outsoles with Obliquely Oriented Tread Patterns

OCCUPATIONAL APPLICATIONSWe systematically examined the effect of obliquely-oriented shoe tread channels on traction performance, by manipulating tread angle, thickness, and gap width across 24 outsole designs. Through robotic slipping tribotesting and computational fluid dynamics modeling, outsoles with a tread inclination angle of 75 and 105 degrees, 2 mm tread thickness, and 5 mm gap width exhibited superior dry and wet traction. This work introduces experimental and computational techniques, offering potential for footwear manufacturers and those who prefer formal shoes to understand the effect of designs on the slip-resistance of a footwear for better safety.

Clinician acceptability of the ReacStep reactive balance training program for fall prevention

AIM

To examine if a novel reactive balance training program (ReacStep) designed for clinical settings is acceptable to clinicians prescribing balance and mobility training.

METHODS

ReacStep consists of tether-release reactive step training, volitional trip and slip training, and functional strength training. An open survey comprising 11-point visual analog scale items (0 = strongly disagree to 10 = strongly agree) based on the Theoretical Framework of Acceptability was sent to clinicians working in balance and mobility training. Items evaluated the acceptability of ReacStep across seven domains (intervention coherence, perceived efficacy, self-efficacy, ethicality, affective attitude, burden and opportunity cost).

RESULTS

Two hundred and seven clinicians (169 Physiotherapists, 22 Exercise Physiologists, 11 Occupational Therapists and five others) completed the survey. Respondents considered ReacStep to have good overall acceptability, intervention coherence, effectiveness, ethicality and self-efficacy (mean acceptability scores >7). However, respondent's ratings of ReacStep's affective attitude, burden and opportunity cost were more variable (mean acceptability scores 2-8) due to concerns about client anxiety, the need for a safety harness and staffing and training requirements. Respondents considered that ReacStep would be more effective and safer to conduct in geriatrics clients compared with neurological clients, and that it would be more appropriate for rehabilitation and private practice settings compared to home settings.

CONCLUSIONS

ReacStep was generally acceptable from the perspective of clinicians who prescribe balance and mobility training in various clinical settings, and was deemed more effective and safer for older clients without neurological conditions, and beneficial in outpatient rehabilitation and private practice settings.

Characteristics of fragility hip fracture-related falls in the older adults: A systematic review

BACKGROUND AND OBJECTIVES

With the global aging trend, the incidence of falls and hip fractures is projected to rise, leading to an increased associated burden. Over 90% of hip fractures result from falls, yet not all falls cause fractures, suggesting specific fall characteristics may contribute to hip fractures. This review provides insights into fragility hip fracture-related falls among the older adults, aiding in understanding and developing effective fall prevention strategies for this population.

METHODS

Searches encompassed PubMed, OVID, EMBASE, Cochrane Library, and Web of Science, supplemented by citation checks. We included non-randomized studies detailing characteristics of fragility hip fracture-related falls in the older individuals, with or without a non-hip fracture control. Evaluated fall characteristics included height, location, direction, time, mechanism, activity during the fall, hip impact, protective responses, walking aid use, and impact surface. Results were analyzed using a narrative synthesis approach. The quality of these studies was assessed using the revised Risk of Bias Assessment tool for Non-randomized Studies 2 (RoBANS2).

RESULTS

A total of 30 articles were reviewed, comprising 23 non-case control and 7 case-control studies, with a mean age of 75.6 years. Studies presented varied details on fall characteristics. Hip-fracture related falls typically occur indoors at or around standing height during daytime, often involving sideways or backward motions with inadequate protective responses. Slipping is predominant, yet lost balance and weakness/collapse are notable. Walking precedes many falls, but stationary activities (lack of forward motion, changing positions, sitting or standing still, transfer) also contribute. Low usage of walking aids and impact on hard surfaces are common features of these falls.

CONCLUSIONS

This review underscores fall characteristics associated with fragility hip fractures in older adults, highlighting features more aligned with age-related physical frailty than general falls. Such insights can guide healthcare providers in implementing tailored interventions to reduce hip fractures and related challenges.

Effects of direction cue time and walking speed on spatial-temporal gait adaptations in healthy older and young adults upon approach of turns

BACKGROUND

Hurrying and turning are each associated with falls in older adults. Losing balance sideways when turning increases the likelihood of hip fracture. Yet 99 % of failures when turning unexpectedly have been traced to an inability to curb forward momentum regardless of age.

RESEARCH QUESTION

Do age-based differences exist in spatial-temporal gait adaptations related to medial-lateral (M-L) balance and posterior-anterior (P-A) propulsion upon approach of turns relative to continuing straight, across walking speeds and whether direction is known in advance?

METHODS

Healthy young (n=10) and older adults (n = 10) walked at preferred and fast test speeds while randomly cued for direction either early upon initiating gait or late 1-2 steps before entering a spatially defined turning area. An instrumented 4.6 m carpet recorded spatial-temporal changes up to the penultimate footfall prior to turning 900 or continuing straight.

RESULTS

When approaching the turning zone across interactions of walking test speed, cue time and direction, other than stride-length being shorter in older adults, both age-groups showed similar adjustments in gait speed and stride-length in managing P-A deceleration perturbations, and similar adaptations in right and left heel-to-heel base of support (BOS) in managing M-L balance destabilizing forces. A three-way interaction (p<.027) suggests a similar foot strategy of BOS narrowing may be used approaching turns relative to straight walks when direction is cued early walking fast (p<.020) and late walking preferred speed (p<.014).

SIGNIFICANCE

The findings were interpreted within the context of regulating center of mass acceleration and processing environmental regulatory conditions to maintain a personal space safety margin. The study supports that in otherwise healthy older adults, gait training for turns include practice to not only manage perturbations which accelerate the body sideways but also those which decelerate forward progression.

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.

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.

Associating white matter microstructural integrity and improvements in reactive stepping in people with Parkinson's Disease

Reactive steps are rapid responses after balance challenges. People with Parkinson's Disease (PwPD) demonstrate impaired reactive stepping, increasing fall-risk. Although PwPD can improve steps through practice, the neural mechanisms contributing to improved reactive stepping are poorly understood. This study investigated white-matter correlates of responsiveness to reactive step training in PwPD. In an eighteen-week multiple-baseline study, participants (n = 22) underwent baseline assessments (B1 and B2 two-weeks apart), a two-week training protocol, and post-training assessments immediately (P1) and two-months (P2) post-training. Assessments involved three backward reactive step trials, measuring anterior-posterior margin of stability (AP MOS), step length, and step latency. Tract-Based Spatial Statistics correlated white-matter integrity (fractional anisotropy (FA) and radial diffusivity (RD)) with retained (P2-B2) and immediate improvements (P1-B2) in stepping. Significant and sustained improvements in step length and AP MOS were observed. Greater retention of step length improvement correlated with increased FA in the left anterior thalamic radiation (ATR), left posterior thalamic radiation (PTR), left superior longitudinal fasciculus (SLF), and right inferior longitudinal fasciculus (ILF). Step latency retention was associated with lower RD in the left posterior corona radiata and left PTR. Immediate improvements in AP MOS correlated with increased FA of the right ILF, right SLF, and right corticospinal tract. Immediate step length improvements were associated with increased FA in right and left ATR and right SLF. These findings highlight the importance of white-matter microstructural integrity in motor learning and retention processes in PD and could aid in identifying individuals with PD who would benefit most from balance rehabilitation.

The effect of virtual reality treadmill training on obstacle crossing parameters in older adults

With increased age, walking without tripping requires greater cognitive demand. Therefore, it may be beneficial for training interventions to address and incorporate aspects of cognitive load. The purpose of this study was to compare a semi-immersive virtual reality treadmill training (VRTT) and conventional treadmill training (CTT) on obstacle clearance and trip hazard in older adults. Obstacle clearance parameters were measured with foot-mounted inertial measurement units (IMUs) and a Zeno pressure walkway. All data were processed and analyzed through custom Matlab scripts. Obstacle step height mean decreased (p = .003) in the lead limb following both training interventions. Additional significant changes were found in pre- and post-obstacle distance mean following both training interventions. Furthermore, significant correlations were found between demographic, cognitive, and functional mobility assessments and changes in dependent measures. The findings suggest that both the VRTT and CTT interventions may provide a reduction in trip risk in older adults, although through different methods.

Reduced adaptability to balance perturbations in older adults with probable cognitive impairment after a severe fall

Falls in older individuals often result from unexpected balance disturbances during walking, necessitating the analysis of recovery strategies for effective falls prevention. This becomes particularly crucial for individuals with cognitive impairment, who face a higher fall risk compared to cognitively healthy adults. Hence, our study aimed to compare the recovery response to standardized walking perturbations on a treadmill between older adults with cognitive impairment and cognitively healthy older adults. 36 individuals with a recent history of a severe fall, leading to an emergency department visit without subsequent admission, were stratified into two groups (with and without probable cognitive impairment) based on scores of the Montreal Cognitive Assessment. Recovery performance was quantified using force plate data from a perturbation treadmill (M-Gait, Motek Medical B.V., Amsterdam, the Netherlands), specifically evaluating the number of steps needed to restore step length and width to pre perturbation baseline across two trials of nine different perturbations. Individuals with cognitive impairment (n = 18, mean age: 74.7) required significantly (p = 0.045, Cohen's d = 0.69) more steps to recover total steps after perturbations compared to cognitively healthy individuals (n = 18, mean age: 69.7). While step width recovery was similar between the groups, those with probable cognitive impairment required significantly more steps to recover their step length (p = 0.039, Cohen's d = 0.72). Thus, our findings indicate that older adults with probable cognitive impairment manifest inferior gait adaptability, especially in adapting step length, potentially underscoring a critical aspect for effective falls prevention in this population.

Overview of Radar-Based Gait Parameter Estimation Techniques for Fall Risk Assessment

Current methods for fall risk assessment rely on Quantitative Gait Analysis (QGA) using costly optical tracking systems, which are often only available at specialized laboratories that may not be easily accessible to rural communities. Radar placed in a home or assisted living facility can acquire continuous ambulatory recordings over extended durations of a subject's natural gait and activity. Thus, radar-based QGA has the potential to capture day-to-day variations in gait, is time efficient and removes the burden for the subject to come to a clinic, providing a more realistic picture of older adults' mobility. Although there has been research on gait-related health monitoring, most of this work focuses on classification-based methods, while only a few consider gait parameter estimation. On the one hand, metrics that are accurately and easily computable from radar data have not been demonstrated to have an established correlation with fall risk or other medical conditions; on the other hand, the accuracy of radar-based estimates of gait parameters that are well-accepted by the medical community as indicators of fall risk have not been adequately validated. This paper provides an overview of emerging radar-based techniques for gait parameter estimation, especially with emphasis on those relevant to fall risk. A pilot study that compares the accuracy of estimating gait parameters from different radar data representations - in particular, the micro-Doppler signature and skeletal point estimates - is conducted based on validation against an 8-camera, marker-based optical tracking system. The results of pilot study are discussed to assess the current state-of-the-art in radar-based QGA and potential directions for future research that can improve radar-based gait parameter estimation accuracy.

The decline in postural balance has a negative impact on the performance of functional tasks in individuals with Parkinson's Disease

INTRODUCTION

An accurate assessment of balance problems is critical for decreasing the risk of falling in patients with Parkinson's Disease (PD). Reliable diagnostic tools such as Computerized Dynamic Posturography (CDP) are not feasible for the clinical setting. Therefore, the present study's aim was to assess the correlation between the clinical Balance Evaluation Systems Test (BESTest) and CDP.

METHODS

20 male older adults with Parkinson's Disease (PD) were included in this study. Participants first executed the Sit-To-Stand (STS), Step/Quick turn (SQT), and Step Up and Over (SUO) tests on a Balance Master® force platform, followed by a clinical balance evaluation using the BESTest.

RESULTS

Four outcomes of the CDP were negatively correlated with one or more BESTest domains or total BESTest score: STS sway velocity was negatively correlated with the anticipatory postural adjustment (p = 0.02) and sensory orientation (p = 0.01) domains. SQT turn time was negatively correlated with biomechanical restriction (for turns to the left, p = 0.01, and right, p = 0.03, respectively), postural response (p = 0.01, p = 0.01), dynamic balance during gait (p = 0.007, p = 0.001), and total score (p = 0.02, p = 0.01). Step over time to the right in SUP was negatively correlated with the limits of the stability domain (p = 0.002) and total BESTest score (p = 0.020). SUO impact index was negatively correlated with the anticipatory postural adjustment domain (p = 0.01).

CONCLUSION

This study shows that several BESTest domains are significantly correlated with CDP outcomes, demonstrating that the BESTest can be used as a more clinically feasible alternative for computerized posturography, without loss of information.

The effect of visual sensory interference during multitask obstacle crossing in younger and older adults

When older adults step over obstacles during multitasking, their performance is impaired; the impairment results from central and/or sensory interference. The purpose was to determine if sensory interference alters performance under low levels of cognitive, temporal, and gait demand, and if the change in performance is different for younger versus older adults. Participants included 17 younger adults (20.9±1.9 years) and 14 older adults (69.7±5.4 years). The concurrent task was a single, simple reaction time (RT) task: depress button in response to light cue. The gait task was stepping over an obstacle (8 m walkway) in three conditions: (1) no sensory interference (no RT task), (2) low sensory interference (light cue on obstacle, allowed concurrent foveation of cue and obstacle), or (3) high sensory interference (light cue away from obstacle, prevented concurrent foveation of cue and obstacle). When standing, the light cue location was not relevant (no sensory interference). An interaction (sensory interference by task, p<0.01) indicated that RT was longer for high sensory interference during walking, but RT was not altered for standing, confirming that sensory interference increased RT during obstacle approach. An interaction (sensory interference by age, p<0.01) was observed for foot placement before the obstacle: With high sensory interference, younger adults placed the trail foot closer to the obstacle while older adults placed it farther back from the obstacle. The change increases the likelihood of tripping with the trail foot for younger adults, but with the lead limb for older adults. Recovery from a lead limb trip is more difficult due to shorter time for corrective actions. Overall, visual sensory interference impaired both RT and gait behavior with low levels of multitask demand. Changes in foot placement increased trip risk for both ages, but for different limbs, reducing the likelihood of balance recovery in older adults.

Dynamic Duo: Design and Validation of an Autonomous Frontal and Sagittal Actuating Hip Exoskeleton for Balance Modulation During Perturbed Locomotion

Humans are required to maintain balance during locomotion in challenging environments, which present an even bigger challenge for individuals with balance impairments. Exoskeleton-driven balance augmentation is a promising avenue to assist users in these environments, but there has been little work in developing exoskeleton devices for these applications. In this work, we present the design, realization, and validation of an autonomous robotic hip exoskeleton with frontal and sagittal actuation. This device contains four quasi-direct drive-actuated degrees of freedom, enabling both frontal and sagittal assistance at the hip joints. The device is relatively light-weight, weighing 7.76 kg, and low-profile in the frontal plane, enabling unimpeded arm swing of the user. We found that wearing the device did not change walking kinematics, validating that the design does not inhibit the user's natural motion. We validated the exoskeleton using a bilateral bang-bang controller that successfully modulated step width and length in all cardinal and ordinal directions (all p<0.001) during steady state and perturbed walking. We also found that step modulation capability is influenced by swing leg kinematics and perturbation context. Broadly, this work presents a lightweight, autonomous, powered exoskeleton that can be used to study control approaches for balance augmentation.

Multifactorial Exercise Intervention Decreases Falls Risk in High-risk and Low-risk Older Adults

BACKGROUND

Each year, 1 in 4 people over the age of 65 years of age will experience a fall. It is important to identify and address modifiable risk factors that are associated with falls in adults at high and low risk for falls.

HYPOTHESIS

Falls risk improves in both high-risk and low-risk participants with the implementation of Stay Active and Independent for Life (SAIL).

STUDY DESIGN

Cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Seventy-eight older adults (age, 70.9 ± 5.1 years) were included in this study and categorized into high risk and low risk for falling based on the falls risk score from the Physiological Profile Assessment. High risk was defined as having a preintervention falls risk score >1, whereas low risk was defined as having a preintervention falls risk score <1. Both groups had the same 10-week intervention. A multivariate analysis of covariance was used to compare differences pre- and postintervention, using preintervention falls risk score as covariate.

RESULTS

Results showed that regardless of preintervention falls risk, participants showed significant improvements in right and left knee extensor strength and sit-to-stand after participation in the 10-week SAIL program. Also, noteworthy is that 15 participants who were considered at high risk for falling preintervention were considered low risk for falling postintervention.

CONCLUSION

The positive outcomes noted on modifiable risk factors suggest SAIL can be beneficial for decreasing falls risk in older adults, regardless of risk of falling, using a multifactorial exercise intervention. Our results also showed that it was possible for participants not only to improve falls risk but to improve to such a degree that they change from high risk to low risk of falling.

CLINICAL RELEVANCE

Our results demonstrated that SAIL was effective in improving overall fall risk after a 10-week intervention. Targeted community-based interventions for the aging population can bring physical health benefits that can decrease falls risk.

Effectiveness of a sensorimotor exercise program on proprioception, balance, muscle strength, functional mobility and risk of falls in older people

Introduction

Sensory systems provide the necessary information for a motor response to be provided. In this sense, the objective of this study is to evaluate the effectiveness of a sensorimotor exercise program on proprioceptive acuity, balance, muscle strength, functional mobility and risk of falls in institutionalized elderly.

Methodology

56 participants (84.6 ± 8.4 years) were randomly distributed between the control (CG, n = 28) and intervention groups (IG, n = 28). The CG performed a protocol based on warm-up, muscle strengthening and warm down and the IG performed the same intervention, with the addition of sensorimotor exercises. Joint Position Sensation (JPS) was evaluated in both limbs at angles of 20° and 45°, balance, functional mobility, fear of falling in the elderly and muscle strength of quadriceps, hamstrings, adductors and abductors in both limbs, before and after the 12 weeks of intervention.

Results

Both groups showed gains in muscle strength. When analyzing functionality through Timed Up and Go (TUG), before and after for each group separately, both showed a significant difference (CG p = 0.002; IG p < 0.001). For the Short Physical Performance Battery (SPPB) variable, there were significant differences in IG in balance (p < 0.001), gait speed time (s) (p = 0.004) and sit-to-stand (p = 0.002). In JPS, significant differences were recorded for Absolute Error 45° Non-Dominant (p = 0.045) and Relative Error 45° Non-Dominant (p = 0.045) in the CG and Relative Error 45° Non-Dominant for IG (p = 0.018). In the Falls Efficacy Scale International (FES-I) variable there were significant improvements in the CG (p = 0.006) and in the GI (p = 0.002). However, only IG showed significant improvements (p = 0.013) for Activities-Specific Balance Confident (ABC) in a comparison between before and after the 12-week research period. When comparing the differences verified with the intervention between CG and IG, only balance SPPB (p < 0.001) and sit-to-stand SPPB (p = 0.022) showed significant values.

Conclusion

He effectiveness of sensorimotor exercises provides balance gain in the elderly (p < 0.001) and positively impacts their confidence (p = 0.013) when performing their duties. It is concluded that the protocol presented in its different levels of difficulty is effective and important for the quality of life of the institutionalized sedentary elderly.

A dynamic spatiotemporal model for fall warning and protection

Early detection of falls is important for reducing fall injuries. However, existing fall detection strategies mostly focus on reducing impact injuries rather than avoiding falls. This study proposed the concept of identifying "Imbalance Point" to warn the body imbalance, allowing sufficient time to recover balance. And if falling cannot be avoided, an impact sign is released by detecting the "Fall Point" prior to the impact. To achieve this goal, motion prediction model and balance recovery model are integrated into a spatiotemporal framework to analyze dynamic and kinematic features of body motion. Eight healthy young volunteers participated in three sets of experiment: Normal trial, Recovery trial and Fall trial. The body motion in the trials was recorded using Microsoft Azure Kinect. The results show that the developed algorithm for Fall Point detection achieved 100% sensitivity and 98.6% specificity, along with an average lead time of 297 ms. Moreover, Imbalance Point was successfully detected in all Fall trials, and the average time interval between Imbalance Point and Fall Point was 315 ms, longer than reported step reaction time for elderly (approximately 270 ms). The experiment results demonstrate that the developed algorithm have great potential for fall warning and protection in the elderly.

Effect of the Visual Illusion on Stepping-Over Action and Its Association with Gaze Behavior

An adequate foot clearance height while stepping over an obstacle is important for safety in daily life. In the present study, we examined whether visual illusions affect foot clearance during a stepping-over action, and whether this is further influenced by gaze behavior. Twelve participants stepped over an obstacle placed four meters away under conditions of three different obstacle characteristics: white, horizontal, or vertical lines. We measured the participants' foot clearances during the step-over action and their gaze behavior during the approaching phase. Participants stepped significantly higher over the obstacles in the vertical lines (illusion) condition. The duration of gaze fixation on the obstacle positively correlated with increased foot clearance in the vertical condition, suggesting that the effect of the visual illusion on foot clearance was enhanced by prolonged gaze fixation. Conversely, prolonged fixation negatively correlated with foot clearance in the white (control) condition, implying that a cautious perception of an obstacle may contribute to efficient stepping-over action.

The "Can Do, Do Do" Framework Applied to Assess the Association between Physical Capacity, Physical Activity and Prospective Falls, Subsequent Fractures, and Mortality in Patients Visiting the Fracture Liaison Service

The "can do, do do" framework combines measures of poor and normal physical capacity (PC, measured by a 6 min walking test, can do/can't do) and physical activity (PA, measured by accelerometer, do do/don't do) into four domains and is able to categorize patient subgroups with distinct clinical characteristics, including fall and fracture risk factors. This study aims to explore the association between domain categorization and prospective fall, fracture, and mortality outcomes. This 6-year prospective study included patients visiting a Fracture Liaison Service with a recent fracture. Outcomes were first fall (at 3 years of follow-up, measured by fall diaries), first subsequent fracture, and mortality (at 6 years). Cumulative incidences of all three outcomes were calculated. The association between domain categorization and time to the three outcomes was assessed by uni- and multivariate Cox proportional hazard analysis with the "can do, do do" group as reference. The physical performance of 400 patients with a recent fracture was assessed (mean age: 64 years; 70.8% female), of whom 61.5%, 20.3%, and 4.9% sustained a first fall, sustained a subsequent fracture, or had died. Domain categorization using the "can do, do do" framework was not associated with time to first fall, subsequent fracture, or mortality in the multivariate Cox regression analysis for all groups. "Can't do, don't do" group: hazard ratio [HR] for first fall: 0.75 (95% confidence interval [CI]: 0.45-1.23), first fracture HR: 0.58 (95% CI: 0.24-1.41), and mortality HR: 1.19 (95% CI: 0.54-6.95). Categorizing patients into a two-dimensional framework seems inadequate to study complex, multifactorial outcomes. A personalized approach based on known fall and fracture risk factors might be preferable.

Curvilinear walking elevates fall risk and modulates slip and compensatory step attributes after unconstrained human slips

While much attention has been paid to understanding slip-related falls in humans, little has been focused on curvilinear paths despite their prevalence, distinct biomechanical demands and increased slipping threat. We determined the mechanics, compensatory stepping reactions and fall risk associated with slips during fixed-speed walking across ranges of path curvature, slipped foot and slip onset phase contexts possible in the community, which builds upon previous work by examining speed-independent effects of curvilinear walking. Twenty-one participants experienced 15 unconstrained slips induced by a wearable friction-reducing device as motion capture and harness load cell data were recorded. Falls were most likely after early stance slips to the inside foot and increased at tighter curvatures. Slip distance and peak velocity decreased as slips began later in stance phase, did not differ between feet, and accelerated on tighter paths. Slipping foot directions relative to heading transitioned from anterior (forward) to posterior (backward) as slips began later in stance, were ipsilateral (toward the slipping foot side) and contralateral (toward the opposite side) for the outside and inside foot, respectively, and became increasingly ipsilateral/contralateral on tighter curvatures. Compensatory steps were placed anteriorly and ipsilaterally after outside and inside foot slips, respectively, and lengthened at later onset phases for outside foot slips only. Our findings illustrate slip magnitude and fall risk relationships that suggest slip direction may influence the balance threat posed by a slip, imply that walking speed may modify slip likelihood, and indicate the most destabilizing curved walking contexts to target in future perturbation-based balance training approaches.

Wearing a back-support exoskeleton alters lower-limb joint kinetics during single-step recovery following a forward loss of balance

We assessed the effects of a passive, back-support exoskeleton (BSE) on lower-limb joint kinetics during the initiation and swing phases of recovery from a forward loss of balance. Sixteen (8M, 8F) young, healthy participants were released from static forward-leaning postures and attempted to recover their balance with a single-step while wearing a BSE (backXTM) with different levels of support torque and in a control condition. The BSE provided ∼ 15-20 Nm of external hip extension torque on the stepping leg at the end of initiation and beginning of swing phases. Participants were unable to generate sufficient hip flexion torque, power, and work to counteract this external torque, although they sustained hip flexion torque for a more prolonged period, resulting in slightly increased hip contribution to positive leg work (compared to control). However, net positive leg work, and the net contribution of hip joint (human + BSE) to total leg work decreased with BSE use. While all participants had changes in hip joint kinetics, a significant compensatory increase in ankle contribution to positive leg work was observed only among females. Our results suggest that BSE use adversely affects reactive stepping by decreasing the stepping leg kinetic energy for forward propulsion, and that the relative contributions of lower-limb joints to total mechanical work done during balance recovery are altered by BSE use. BSEs may thus need to be implemented with caution for dynamic tasks in occupational settings, as they may impair balance recovery following a forward loss of balance.

Proprioceptive and Strength Exercise Guidelines to Prevent Falls in the Elderly Related to Biomechanical Movement Characteristics

Falls are a major concern in the elderly and walking is an important daily activity in which falls occur, with tripping and slipping being the most frequent causes. Gait biomechanical parameters have been related to the occurrence of falls in the elderly. Moreover, there is evidence that falls can be prevented through exercise programs, which have been shown to be also effective in improving gait biomechanical parameters. However, a question remains: "What types of exercises must be included in exercise programs to prevent falls?". The purpose of this manuscript was to present guidelines for a fall prevention exercise program for the elderly, which was created with the aim of improving the gait biomechanical parameters related to falls. The critical review performed during the preparation of this manuscript collected important evidence and knowledge in order to create a structural basis for the development of a fall prevention exercise program. This type of program should last 6 or more weeks and be prescribed based on four movement pillars (locomotion, level changes, pulling and pushing, and rotations); however, the locomotion pillar must be the focus of the program. Proprioceptive and functional strength exercises should be included in this program. Based on the theoretical rationale, a proposal for a fall prevention exercise program is presented.

Detecting differences in limb load asymmetry during walking between older adult fallers and non-fallers using in-shoe sensors

BACKGROUND

Previous studies have reported that clinical walk tests could not detect differences between fallers and non-fallers in older adults. With advancements in wearable technology, it may be possible to assess differences in loading parameters in clinical settings using portable data collection methods.

RESEARCH QUESTION

The purpose of this study was to determine if wearable sensors (loadsol®) are reliable for assessing asymmetry of contact time, peak force, loading rate (LR), and impulse in older adults and determine if the insole can detect differences in these parameters between fallers and non-fallers during walking.

METHODS

Fifty-five older adults (74.1 ± 6.1 years) walked at their maximum speed on a flat floor. Force data were collected from insoles (100 Hz) during a 10-m walk test. To assess reliability, an intraclass correlation coefficient [ICC(2,k)] was generated for each asymmetry variable. To determine differences between fallers and non-fallers, analysis of covariance (ANCOVA; covariate: body mass index) was completed for each variable.

RESULTS

The ICC of peak force asymmetry (PFA) was 0.942, but other ICCs were less than 0.75. The ANCOVA results indicate that the loadsol® can detect differences in PFA between fallers and non-fallers. The PFA was significantly greater in fallers than in non-fallers.

SIGNIFICANCE

The ability to collect force data while walking using loadsol® has the potential to broaden the research questions investigated, explore clinical applications, and increase generalizability.

Lower extremity joint power and work during recovery following trip-induced perturbations

BACKGROUND

Successful recovery following a perturbation during walking depends on a quick well-coordinated response from the body. As such, lower limb joint power and work provide critical information characterizing the success of the recovery after a perturbation. Therefore, this study aimed to investigate lower-limb joint power and the relative contribution of each joint to the total leg work during the recovery following a trip-induced perturbation.

METHODS

Twenty-four young male volunteers walked at 1.1 m/s for 2 min, followed by two unexpected perturbations induced by rapidly decelerating the right belt of the split-belt treadmill. Joint moments and powers were calculated using an inverse dynamic approach. Joint work was found as the integral of joint power with respect to time. Statistical parametric mapping (SPM) and paired-sample t-tests were used to compare joint power and work between recovery and unperturbed steps.

RESULTS

Compared to normal walking, recovery from the trip required a significant increase in both positive (+27 %, p < 0.05) and negative(+28 %,p < 0.05) leg work. During unperturbed walking, the ankle was the key contributor to both positive (ankle=50 %, hip=34 %, and knee=15 %) and negative (ankle=62 %, knee=32 %, and hip=6 %) leg work. During recovery, the knee eccentric work significantly increased (+83 %,p < 0.05) making it the main contributor to the negative leg work (knee=46 %, ankle=45 %, and hip=9 %). The hip positive work also increased during recovery (+62.7 %, p < 0.05), while ankle and the knee positive work remained unchanged.

SIGNIFICANCE

These findings highlight the importance of eccentric work of the knee, and concentric work of the hip joint during recovery from trip-induced perturbations. The additional mechanical demand of producing and absorbing more power during recovery is primarily imposed on the knee and hip, rather than the ankle. This new insight into the specific functions of lower-limb joints during recovery from trip-induced perturbations has important implications for the design of targeted fall prevention interventions.

Effects of Perturbation-Based Treadmill Training on Balance Performance, Daily Life Gait, and Falls in Older Adults: REACT Randomized Controlled Trial

OBJECTIVE

The aim of this study was to evaluate the effect of perturbation-based treadmill training on gait quality in daily life, a predictor of fall risk that was used as the primary outcome. An additional aim was to evaluate the effects on secondary outcomes, including balance, gait performance, self-efficacy, daily life physical activity, and falls.

METHODS

Seventy community-dwelling older adults (mean age = 74.73 [SD = 5.69] years; 46 women) at risk of falling were randomized and received 4 weeks of dual-task treadmill training, either with or without treadmill perturbations. Balance, gait performance, self-efficacy, and daily life trunk accelerometry at baseline, after intervention, and at a 6-month follow-up were assessed and compared within group over time and between groups for each time point, and their change rates between groups over time were also assessed.

RESULTS

Both groups improved in their balance, gait performance, and self-efficacy; the experimental group showed a significantly larger decrease in concern of falling and an increase in physical performance than the controls. These training effects did not translate into significant improvements in daily life gait quality or physical activity. However, the number of daily life falls and the percentage of fallers decreased significantly more in the experimental group.

CONCLUSION

A 4-week perturbation-based dual-task treadmill training program can improve self-efficacy, balance, and gait performance in a controlled setting and reduce daily life falls, although not through changes in quantity or quality of daily life gait.

IMPACT

Perturbation-based treadmill training is a safe and efficient way to train older adults' balance recovery and gait performance, increase self-efficacy, and prevent falls.

Fall experiences from the perspectives of people with osteoarthritis: in their own words

PURPOSE

To explore real-life experiences of people with osteoarthritis (OA) to increase understanding of how they perceive contributing factors to falls, circumstances at time of falls, and consequences of falls.

MATERIALS AND METHODS

Four focus groups of 3-7 people with OA from the Chicago, IL, USA, and neighboring areas were conducted remotely via web-based videoconferencing. Inclusion criteria included history of falls in previous 12 months and hip and/or knee OA. Focus group transcripts were coded and analyzed using a modified grounded theory approach to identify themes.

RESULTS

Focus group participants (n = 17) described experiences associated with fall-related events that resulted in the identification of four themes: (1) perception of falls and fall risks can be influenced by OA symptoms, (2) ability to remember circumstances of falls are influenced by consequences, (3) behaviors and attitudes that address OA symptoms and avoidance of falls are similar and (4) OA symptoms and falls have common psychological impacts on lives.

CONCLUSION

Our study highlights how people with OA define falls, perceive contributing factors to falls, and describe general and OA-related factors that contributed to their fall experiences. The shared experiences contributed to the creation of themes that represented various aspects of the circumstances and impact of falls. Consideration for the identified themes may enhance recording and reporting of falls, contribute to development of improved fall risk assessment tools, and prioritize research into the biopsychosocial effects of falls in people with OA.IMPLICATIONS FOR REHABILITATIONInformation about circumstances of a fall such as location, activity, and symptoms of osteoarthritis may be beneficial in creating tailored fall prevention training and education.Falls are a common problem for people with lower limb osteoarthritis that can lead to negative changes in activity and quality of life.The psychological impact of osteoarthritis symptoms may be contributing to fear of falling and decrease participation in daily activities.Awareness of the perceptions people with osteoarthritis have about their symptoms may provide educational and training opportunities to address the benefits of different therapeutic treatments.Awareness of perceptions people with osteoarthritis have about their risk of falling may provide educational and training opportunities to address the benefits of different therapeutic treatments.

Can minimum toe clearance predict community-based trips by older adults?

BACKGROUND

Tripping is the leading cause of falls by older adults. While tripping theoretically occurs when minimum toe clearance (MTC) is insufficient to avoid an unseen obstacle, the relationship between MTC and community-based trips is unknown.

RESEARCH QUESTION

To what extent do MTC and its variability predict the number of community-based trips during gait by older adults?

METHOD

51 older adults with normal or obese body mass index walked across an 8 m walkway. For each step, we identified MTC as the local minimum of the vertical trajectory of a toe marker during the swing phase. We calculated the across-steps mean, median, interquartile range, and standard deviation for MTC, and skewness and kurtosis of the distribution of all MTC values for an individual. Every two weeks for one year, participants reported on community-based trips. A series of negative binomial regressions were used to predict the number of trips over obstacles (with or without a fall) based on MTC measures.

RESULTS

28 participants experienced at least one trip, with 14 experiencing two or more. In the absence of any covariates, only kurtosis and skewness significantly predicted the incidence rate of trips. However, neither remained significant after accounting for fall history. The model that included kurtosis and fall history predicted trips better than one with fall history alone, with the incidence rate of trips decreasing by 35% for every unit increase in kurtosis (incidence rate ratio of 0.64 with 95% confidence interval: 0.38 - 1.08; p = 0.09) SIGNIFICANCE: While MTC has the potential to provide insight into older adults more likely to trip over obstacles in the community, assessing MTC during level-ground walking within a lab environment may lack ecological validity to strongly describe the risk of community-based trips above and beyond fall history.

Stability Changes in Fall-Prone Individuals With Parkinson Disease Following Reactive Step Training

BACKGROUND AND PURPOSE

Poor reactive steps may lead to falls in people with Parkinson disease (PwPD). However, whether reactive steps can be improved in PwPD at risk for falls or whether step training reduces falls remains unclear. This study aimed to determine whether 2 weeks of reactive step training result in (1) immediate and retained improvements in stepping and (2) fewer prospective falls in PwPD at fall risk.

METHODS

Twenty-five PwPD (70.52 years ± 7.15; Hoehn & Yahr range 1-3) at risk for falls completed a multiple baseline, open-label, uncontrolled pre-/postintervention study. Stepping performance was assessed at 2 baseline assessments (B1 and B2) followed by a 2-week, 6-session training protocol. Stepping was assessed immediately (P1) and 2 months after training (P2). Primary outcomes were anterior-posterior margin of stability (MOS), step length, and step latency during backward stepping. Fall frequency was measured for 2 months before and after training.

RESULTS

MOS during backward steps was significantly larger (better) after training ( P < 0.001, d = 0.83), and improvements were retained for 2 months ( P = 0.04, d = 0.66). Step length was not statistically significant different after training ( P = 0.13, d = 0.46) or at follow-up ( P = 0.08, d = 0.62), although effect sizes were medium and large, respectively. Step latency improved after initial exposure ( P = 0.01, d = 0.60) but not following training ( P = 0.43, d = 0.35). Twelve participants experienced fewer falls after training than before (10 = no change, 5 = increase; P = 0.12). Greater improvements in MOS were related to fewer falls ( P = 0.04).

DISCUSSION AND CONCLUSIONS

Two weeks of reactive step training resulted in immediate and retained improvements in some reactive stepping outcomes in PwPD at risk for falls and may reduce fall risk. Reactive step training may be a viable approach to reduce falls in PwPD.

The Mediating Role of Sarcopenia in the Association between Physical Activity and Falls among Chinese Older Adults: A Cross-Sectional Study

Physical inactivity and sarcopenia are potentially modifiable risk factors for falls in older adults, but the strength of the association between physical activity (PA), sarcopenia, and falls in Chinese older adults is unclear. This study sought to investigate the potential mediation mechanism relationship in the connection between PA, sarcopenia, including its elements (muscle strength, physical performance, and skeletal muscle mass), and falls among Chinese older people. The subjects were 3592 community-dwelling Chinese aged 60 or over, selected from the China Health and Retirement Longitudinal Study (CHARLS). PA was evaluated through the International Physical Activity Questionnaire (IPAQ), and sarcopenia was determined through the Asian Working Group on Sarcopenia (AWGS) 2019 guidelines. We employed logistic regression to explore the link between physical activity, sarcopenia, and falls. Additionally, we applied Karlson, Holm and Breen's (KHB) method to estimate two different mediation models. The results demonstrated that PA lowers the risk of falls [odds ratio (OR) 0.54, 95% confidence interval (CI) 0.48-0.61], whereas sarcopenia increases the risk of falls (OR 1.34, 95% CI 1.16-1.55). Sarcopenia mediated the association between PA and falls, explaining a total of 2.69% of the association (indirect effect = -0.02). PA also had a significant mediating effect on the association between sarcopenia and falls, explaining a total of 20.12% of the association (indirect effect = 0.06). The proportion mediated by sarcopenia was 2.69% for PA and falls (indirect effect = -0.02). Our findings suggest that PA and sarcopenia have a direct effect on falls as well as an indirect effect through each other. Enhancing PA levels and preventing sarcopenia may help prevent falls in older adults.

Exploring Population Characteristics and Recruitment Challenges in Older People Experiencing Falls at Home without Hospitalization or with an Emergency Department Visit: Insights from the RISING-DOM Experience

Background

An increasing number of falls among community-living older adults are reported in emergency calls. Data on evidence of appropriate fall prevention interventions are limited and challenges in recruiting this population in randomized trials are acknowledged.

Purpose

The main aim of this study was to provide demographic data, circumstance and fall-related outcomes of the population in the RISING-DOM study [Impact d'une évaluation des facteurs de RISque de chute et d'une prise en charge personnalisée, sur la mortalité et l'institutionnalisation, après INtervention du SAMU chez la personne âGée à DOMicile], a multicenter, randomized interventional trial involving community-dwelling older adults who have experienced a fall at home and were not hospitalized. Additionally, the challenges of remote recruitment in this population were discussed.

Patients and Methods

Participants were identified through the Occitania Emergency Observatory database. Participant recruitment and data collection were performed through telephone interviews (October 2019-March 2022). Additionally, a sample survey of Emergency Medical Services calls was carried out.

Results

Out of the 1151 individuals screened, a total of 951 participants were included in the trial follow-up, resulting in an acceptance rate of 82.62%. The screening delay was extended due to the COVID-19 pandemic. Recruiting difficulties were mainly related to identifying potential participants, unavailable contact information and unreachability. Participants' mean age was 84.1 years, 65.8% were women, and 44.3% lived alone. Pain was the most frequent outcome (53%). In the previous year, 73.5% of participants reported experiencing a fall, with 66.7% of those falls requiring assistance from Emergency Medical Services (EMS). Nearly, 40% did not take proactive steps to prevent future falls and walking aids (79.8%) were the most common preventive action.

Conclusion

Indicators of a high-risk group of falls have been identified underscoring the need for appropriate fall interventions in the target population. Challenges of large sampling for randomized fall prevention trials were provided.

Trial Registration

Clinicaltrials.gov identifier: NCT04132544. Registration date: 18/10/2019. https://www.clinicaltrials.gov/ct2/show/NCT04132544?term=rising-dom&draw=2&rank=1.

Indoor falls and number of previous falls are independent risk factors for long-term mortality after a hip fracture

BACKGROUND

Hip fractures are almost always the result of a fall. Causes and circumstances of falls may differ between frail and vigorous patients.

AIM

To describe the circumstances of falls causing hip fractures, number of falls during the previous year, and their association with long-term mortality.

PATIENTS AND METHODS

The study is a retrospective review conducted in a tertiary university hospital serving a population of 425,000 inhabitants in Barcelona. All patients admitted with hip fractures with medical records describing the circumstances and number of previous falls were included. The number of falls in the previous 12 months was recorded, including the one causing the fracture. The circumstances of the index fall were dichotomized according to whether it was from the patient's own height or above; day or night; indoors or outdoors, due to intrinsic or extrinsic causes. Cumulative mortality was recorded for almost 5 years after hip fracture.

RESULTS

Indoor falls were strongly associated with shorter survival. Falling more than once in the previous year was also a risk factor for long-term mortality (hazard ratio 1.461, p < 0.001 and hazard ratio 1.035, p = 0.008 respectively).

CONCLUSION

Indoor falls and falling more than once in the previous year are long-term risk factors for mortality after hip fractures. It is always essential to take a careful patient history on admission to determine the number of falls and their circumstances, and special care should be taken to reduce mortality in patients at high risk.