Professor Stephen Lord

PUBLICATIONS

Inaccurate judgement of reach is associated with slow reaction time, poor balance, impaired executive function and predicts prospective falls in older people with cognitive impairment.

Taylor ME, Butler AA, Lord SR, Delbaere K, Kurrle SE, Mikolaizak AS, Close JCT

Inaccurate reach judgement predicts future falls and is associated with poorer global cognitive performance and executive function, increased concern about falling, slower reaction time and poorer balance. Our results offer insight into the disparity between actual and perceived physical capabilities in people with CI, and how this impacts their risk of falling.

Reaction Time and Postural Sway Modify the Effect of Executive Function on Risk of Falls in Older People with Mild to Moderate Cognitive Impairment.

Taylor ME, Lord SR, Delbaere K, Kurrle SE, Mikolaizak AS, Close JCT

To explore the relationship between cognitive performance and falls in older people with mild to moderate cognitive impairment (CI) by investigating the mediational effects of medical, medication, neuropsychological, and physiological factors. Within this sample of older people with mild to moderate CI, poorer EF increased the risk of multiple falls. This relationship was mediated by reaction time and postural sway,suggesting cognitively impaired older people with poorer EF may benefit from fall prevention programs targeting these mediating factors.

Neuropsychological, physical, and functional mobility measures associated with falls in cognitively impaired older adults.

Taylor ME, Delbaere K, Lord SR, Mikolaizak AS, Brodaty H, Close JC

This study identified several risk factors of falls in older people with cognitive impairment, a number of which are potentially modifiable. Future research involving targeted interventions addressing medication use, balance, mood, and functional performance may prove useful for fall prevention in this population.

Systematic review of non-transportation rates and outcomes for older people who have fallen after ambulance service call-out.

Mikolaizak AS, Simpson PM, Tiedemann A, Lord SR, Close JC

Limited but promising evidence shows that appropriate interventions can improve health outcomes of non-transported older people who have fallen. Further studies are needed to explore alternate care pathways and promote more efficient use of health services.

Older fallers attended to by an ambulance but not transported to hospital: a vulnerable population at high risk of future falls.

Tiedemann A, Mikolaizak AS, Sherrington C, Segin K, Lord SR, Close JC

This prospective cohort study describes older non-transported fallers seen by the Ambulance Service of New South Wales (ASNSW), quantifies the level of risk and identifies predictors of future falls and ambulance use. Older, non-transported fallers seen by the ASNSW are a vulnerable population with high rates of chronic health conditions.

Discriminative ability and predictive validity of the timed up and go test in identifying older people who fall: systematic review and meta-analysis.

Schoene D, Wu SM, Mikolaizak AS, Menant JC, Smith ST, Delbaere K, Lord SR

To investigate the discriminative ability and diagnostic accuracy of the Timed Up and Go Test (TUG) as a clinical screening instrument for identifying older people at risk of falling. The findings suggest that the TUG is not useful for discriminating fallers from non-fallers in healthy, high-functioning older people but is of more value in less-healthy, lower-functioning older people. Overall, the predictive ability and diagnostic accuracy of the TUG are at best moderate. No cut-point can be recommended. Quick, multifactorial fall risk screens should be considered to provide additional information for identifying older people at risk of falls.

Physiological fall risk factors in cognitively impaired older people: a one-year prospective study.

Taylor ME, Lord SR, Delbaere K, Mikolaizak AS, Close JC

These findings indicate poor performance on physiological fall risk factors, particularly balance, increases the risk of falls in older cognitively impaired people.

Gait parameter risk factors for falls under simple and dual task conditions in cognitively impaired older people.

Taylor ME, Delbaere K, Mikolaizak AS, Lord SR, Close JC

Physical impairments in cognitively impaired older people: implications for risk of falls.

Taylor ME, Delbaere K, Lord SR, Mikolaizak AS, Close JC

Fall risk in the CIG was significantly increased due to multiple physical impairments. Physical profiles provide a means of quantifying the extent of impairment in older people with cognitive impairment and potential direction for targeting interventions for reducing fall risk.

Gait impairment and falls in cognitively impaired older adults: an explanatory model of sensorimotor and neuropsychological mediators.

Taylor ME, Ketels MM, Delbaere K, Lord SR, Mikolaizak AS, Close JC

to explore the associations between spatiotemporal gait parameters and falls in cognitively impaired older people and to investigate whether sensorimotor and neuropsychological factors mediate the association between gait performance and falls. the findings indicate that slow and variable gait patterns increase the risk of falls in cognitively impaired older adults. Further, the association between gait and falls seems to be mediated in large by reduced sensorimotor functioning. Further research is needed to investigate whether interventions aimed at improving gait and/or sensorimotor fall risk factors, such as strength and balance, can prevent falls in cognitively impaired older adults.

The Falls Efficacy Scale International (FES-I). A comprehensive longitudinal validation study.

Delbaere K, Close JC, Mikolaizak AS, Sachdev PS, Brodaty H, Lord SR

this study aimed to perform a comprehensive validation of the 16-item and 7-item Falls Efficacy Scale International (FES-I) by investigating the overall structure and measurement properties, convergent and predictive validity and responsiveness to change. the current study builds on the previously established psychometric properties of the FES-I. Both scales have acceptable structures, good validity and reliability and can be recommended for research and clinical purposes. Future studies should explore the FES-I's responsiveness to change during intervention studies and confirm suggested cut-points in other settings, larger samples and across different cultures.

Quality of Daily-Life Gait: Novel Outcome for Trials that Focus on Balance, Mobility, and Falls.

van Schooten KS, Pijnappels M, Lord SR, van Dieën JH

Older People with Dementia Have Reduced Daily-Life Activity and Impaired Daily-Life Gait When Compared to Age-Sex Matched Controls.

Taylor ME, Brodie MA, van Schooten KS, Delbaere K, Close JCT, Payne N, Webster L, Chow J, McInerney G, Kurrle SE, Lord SR

Concern About Falling Is Associated With Gait Speed, Independently From Physical and Cognitive Function.

van Schooten KS, Freiberger E, Sillevis Smitt M, Keppner V, Sieber C, Lord SR, Delbaere K

The aim of this study was to examine the effects of concern about falling on gait speed, adjusted for physiological fall risk and cognitive function. Gait speed, especially under dual-task conditions, was affected by concern about falling. Concern about falling was the strongest predictor of gait speed under all 4 conditions and should be included in routine geriatric assessments.

Catch the ruler: concurrent validity and test-retest reliability of the ReacStick measures of reaction time and inhibitory executive function in older people.

van Schooten KS, Duran L, Visschedijk M, Pijnappels M, Lord SR, Richardson J, Delbaere K

The ReacStick is a reliable test of reaction time and inhibitory EF in older people and could have value for fall-risk assessment.

Reducing the burden of dizziness in middle-aged and older people: A multifactorial, tailored, single-blind randomized controlled trial.

Menant JC, Migliaccio AA, Sturnieks DL, Hicks C, Lo J, Ratanapongleka M, Turner J, Delbaere K, Titov N, Meinrath D, McVeigh C, Close JCT, Lord SR

A multifactorial tailored approach for treating dizziness was effective in reducing dizziness handicap in community-living people aged 50 years and older. No difference was seen on the other primary outcomes. Our findings therefore support the implementation of individualized, multifaceted evidence-based therapies to reduce self-perceived disability associated with dizziness in middle-aged and older people.

Head and trunk stability during gait before and after levodopa intake in Parkinson's disease subtypes.

Pelicioni PHS, Brodie MA, Latt MD, Menant JC, Menz HB, Fung VSC, Lord SR

People with the PD PIGD subtype exhibit impaired gait stability that is not improved and frequently worsened by levodopa. New non-pharmaceutical approaches, technological (e.g. cueing) or exercise-based (e.g. balance training) are required to improve or compensate for mediolateral gait instability in this subtype and ultimately prevent falls.

A busy day has minimal effect on factors associated with falls in older people: An ecological randomised crossover trial.

Sturnieks DL, Yak SL, Ratanapongleka M, Lord SR, Menant JC

Stepping reaction time and gait adaptability are significantly impaired in people with Parkinson's disease: Implications for fall risk.

Caetano MJD, Lord SR, Allen NE, Brodie MA, Song J, Paul SS, Canning CG, Menant JC

People with PD have reduced ability to adapt gait to unexpected targets and obstacles and exhibit poorer stepping responses, particularly in a test condition involving conflict resolution. Such impaired stepping responses in Parkinson's disease are associated with disease severity, cognitive impairment and falls.

Executive functioning, concern about falling and quadriceps strength mediate the relationship between impaired gait adaptability and fall risk in older people.

Caetano MJD, Lord SR, Brodie MA, Schoene D, Pelicioni PHS, Sturnieks DL, Menant JC

Impaired gait adaptability is associated with high risk of falls in older adults. Reduced executive function, increased concern about falling and weaker quadriceps strength contribute significantly to this relationship. Training gait adaptability directly, as well as addressing the above mediators through cognitive, behavioural and physical training may maximise fall prevention efficacy.

Head and trunk stability during gait before and after levodopa intake in Parkinson's disease subtypes.

Pelicioni PHS, Brodie MA, Latt MD, Menant JC, Menz HB, Fung VSC, Lord SR

People with the PD PIGD subtype exhibit impaired gait stability that is not improved and frequently worsened by levodopa. New non-pharmaceutical approaches, technological (e.g. cueing) or exercise-based (e.g. balance training) are required to improve or compensate for mediolateral gait instability in this subtype and ultimately prevent falls.

Executive functioning, concern about falling and quadriceps strength mediate the relationship between impaired gait adaptability and fall risk in older people.

Caetano MJD, Lord SR, Brodie MA, Schoene D, Pelicioni PHS, Sturnieks DL, Menant JC

Impaired gait adaptability is associated with high risk of falls in older adults. Reduced executive function, increased concern about falling and weaker quadriceps strength contribute significantly to this relationship. Training gait adaptability directly, as well as addressing the above mediators through cognitive, behavioural and physical training may maximise fall prevention efficacy.

White matter hyperintensities are associated with falls in older people with dementia.

Taylor ME, Lord SR, Delbaere K, Wen W, Jiang J, Brodaty H, Kurrle SE, Stefanie Mikolaizak A, Close JCT

White Matter Hyperintensities (WMHs) are associated with impaired gait, balance and cognition and increased fall risk in cognitively healthy older people. However, few studies have examined such relationships in older people with dementia. Understanding the role of WMHs in falls may assist in developing effective fall prevention strategies. We investigated the relationship between baseline WMHs, cognitive and sensorimotor function and prospective falls in older people with dementia. Twenty-eight community-dwelling older people with mild-moderate dementia (MMSE 11-23; ACE-R < 83) underwent magnetic resonance imaging and assessment of sensorimotor and cognitive (global and processing speed) function at baseline. WMHs, were quantified using a fully automated segmentation toolbox, UBO Detector ( https://cheba.unsw.edu.au/group/neuroimaging-pipeline ). Falls were ascertained prospectively for 12-months using monthly calendars with the assistance of carers. The median age of the participants was 83 years (IQR 77-86); 36% were female; 21 (75%) fell during follow-up. Using Generalized Linear Models, larger volumes of total WMHs were found to be significantly associated with poorer global cognitive and sensorimotor function. Using modified Poisson regression, total, periventricular and deep WMHs were each associated with future falls while controlling for age, sex, intracranial volume and vascular risk. Each standard deviation increase in total and periventricular WMH volume resulted in a 33% (RR 1.33 95%CI 1.07-1.66) and 30% (RR 1.30 95%CI 1.06-1.60) increased risk of falling, respectively. When the deep WMH volume z-scores were dichotomized at the median, individuals with greater deep WMH volumes had an 81% (RR 1.81 95% CI 1.02-3.21) increased risk of falling. WMHs were associated with poorer sensorimotor and cognitive function in people with dementia and total, periventricular and deep WMHs were associated with falls. Further research is needed to confirm these preliminary findings and explore the impact of vascular risk reduction strategies on WMHs, functional performance and falls.

Reducing the burden of dizziness in middle-aged and older people: A multifactorial, tailored, single-blind randomized controlled trial.

Menant JC, Migliaccio AA, Sturnieks DL, Hicks C, Lo J, Ratanapongleka M, Turner J, Delbaere K, Titov N, Meinrath D, McVeigh C, Close JCT, Lord SR

A multifactorial tailored approach for treating dizziness was effective in reducing dizziness handicap in community-living people aged 50 years and older. No difference was seen on the other primary outcomes. Our findings therefore support the implementation of individualized, multifaceted evidence-based therapies to reduce self-perceived disability associated with dizziness in middle-aged and older people.

The role of cognitive function and physical activity in physical decline in older adults across the cognitive spectrum.

Taylor ME, Boripuntakul S, Toson B, Close JCT, Lord SR, Kochan NA, Sachdev PS, Brodaty H, Delbaere K

The aim of this study was to investigate physical decline over 1-year in a cohort of older people across the cognitive spectrum.

Deep white matter hyperintensities, microstructural integrity and dual task walking in older people.

Ghanavati T, Smitt MS, Lord SR, Sachdev P, Wen W, Kochan NA, Brodaty H, Delbaere K

To examine neural, physiological and cognitive influences on gait speed under single and dual-task conditions. Sixty-two community-dwelling older people (aged 80.0 ± 4.2 years) participated in our study. Gait speed was assessed with a timed 20-meter walk under single and dual-task (reciting alternate letters of the alphabet) conditions. Participants also underwent tests to estimate physiological fall risk based on five measures of sensorimotor function, cognitive function across five domains, brain white matter (WM) hyperintensities and WM microstructural integrity by measuring fractional anisotropy (FA). Univariate linear regression analyses showed that global physiological and cognitive measures were associated with single (β = 0.594 and β=-0.297, respectively) and dual-task gait speed (β = 0.306 and β=-0.362, respectively). Deep WMHs were associated with dual-task gait speed only (β = 0.257). Multivariate mediational analyses showed that global and executive cognition reduced the strength of the association between deep WMHs and dual-task gait speed by 27% (β = 0.188) and 44% (β = 0.145) respectively. There was a significant linear association between single-task gait speed and mean FA values of the genu (β=-0.295) and splenium (β=-0.326) of the corpus callosum, and between dual-task gait speed and mean FA values of Superior Cerebellar Peduncle (β=-0.284), splenium of the Corpus Callosum (β=-0.286) and Cingulum (β=-0.351). Greater deep WMH volumes are associated with slower walking speed under dual-task conditions, and this relationship is mediated in part by global cognition and executive abilities specifically. Furthermore, both cerebellum and cingulum are related to dual-task walking due to their role in motor skill performance and attention, respectively.

Slow gait speed is associated with executive function decline in older people with mild to moderate dementia: A one year longitudinal study.

Taylor ME, Lasschuit DA, Lord SR, Delbaere K, Kurrle SE, Mikolaizak AS, Kvelde T, Close JCT

This study aimed to document change in neuropsychological, physical and functional performance over one year and to investigate the relationship between baseline gait speed and cognitive decline in this period in older people with dementia. Older people with mild to moderate dementia demonstrate significant decline in neuropsychological, physical and functional performance over one year. Baseline gait speed is associated with decline in executive function over one year, suggesting shared pathways/pathology between gait and cognition.

Home-based step training using videogame technology in people with Parkinson's disease: a single-blinded randomised controlled trial.

Song J, Paul SS, Caetano MJD, Smith S, Dibble LE, Love R, Schoene D, Menant JC, Sherrington C, Lord SR, Canning CG, Allen NE

To determine whether 12-week home-based exergame step training can improve stepping performance, gait and complementary physical and neuropsychological measures associated with falls in Parkinson's disease. Overall, home-based exergame step training was not effective in improving the outcomes assessed. However, the improved physical function in the lower disease severity intervention participants as well as the self-reported improved mobility in the intervention group suggest home-based exergame step training may have benefits for some people with Parkinson's disease.

Physiological risk factors for falls in older people with lower limb arthritis.

Sturnieks DL, Tiedemann A, Chapman K, Munro B, Murray SM, Lord SR

To investigate physiological risk factors for falls in people with self-reported lower limb arthritis. Older people with lower limb arthritis are at increased risk of falling due to deficits in neuromuscular systems. A physiological falls-risk profile based on mean test scores for the arthritis group highlights deficits in muscular strength, knee proprioception, and standing balance, indicating the need for targeted falls prevention interventions for this population.

The physiology of falling: assessment and prevention strategies for older people.

Lord SR, Sturnieks DL

Balance calls upon contributions from vision, peripheral sensation, vestibular sense, muscle strength, neuromuscular control and reaction time. With increased age, there is a progressive loss of functioning of these systems and an increased likelihood of falls. Falls can mark the beginning of a decline in function and independence and are the leading cause of injury-related hospitalisation in older people. By using simple tests of vision, leg sensation, muscle strength, reaction time and standing balance, it is possible to identify accurately older people at risk of falls and assess intervention outcomes. This approach overcomes the limitations associated with traditional methods of assessing falls risk via medical diagnoses, including varied severity between individuals. Using a physiological approach provides information at the impairment and functional capacity levels to assist in understanding falls and developing and evaluating optimal falls prevention strategies for older people.

Effects of spatial and nonspatial memory tasks on choice stepping reaction time in older people.

Sturnieks DL, St George R, Fitzpatrick RC, Lord SR

The findings suggest that VS cognitive tasks affect CSRT more so than do NS tasks. The visuospatial sketchpad appears to be specifically utilized for carrying out motor tasks necessary for preserving balance. Practical implications are that tasks that require visuospatial attention and memory may adversely influence balance control in older people.

Balance disorders in the elderly.

Sturnieks DL, St George R, Lord SR

Good balance is an imperative skill for daily life that requires the complex integration of sensory information regarding the position of the body relative to the surroundings and the ability to generate appropriate motor responses to control body movement. Balance calls upon contributions from vision, vestibular sense, proprioception, muscle strength and reaction time. With increased age, there is a progressive loss of functioning of these systems which can contribute to balance deficits. Balance disorders represent a growing public health concern due to the association with falls and fall-related injuries, particularly in regions of the world in which high proportions of the population are elderly. Falls present one of the most serious and costly problems associated with older adulthood. Falls can mark the beginning of a decline in function and independence and are the leading cause of injury-related hospitalisation in older people. One in three people over the age of 65 years who are living in the community experience at least one fall each year and 10-15% of these falls are associated with serious injury. In economic terms, the direct and indirect costs associated with falls are large and will grow as the proportion of older people increases. Consequently, understanding age-related changes in the physiological systems imperative to balance is of utmost importance to prevent falls in older people and reduce the injury-related burden on individuals and society.

Concern about falls elicits changes in gait parameters in conditions of postural threat in older people.

Delbaere K, Sturnieks DL, Crombez G, Lord SR

These findings suggest that walking performance is influenced by both physiological and psychological factors. Physiological falls risk appears to determine walking speed under optimal conditions, whereas concern about falling elicits greater (possibly excessive) gait adjustments under conditions of postural threat.

Exercise for falls prevention in older people: assessing the knowledge of exercise science students.

Sturnieks DL, Finch CF, Close JC, Tiedemann A, Lord SR, Pascoe DA

Participation in appropriate exercise can help reduce the risk of falls and falls injury in older people. Delivery of population-level exercise interventions requires an expert workforce with skills in development and delivery of group exercise programs and prescription of individually targeted exercise. This study assessed the current knowledge of university exercise science students (as future exercise professionals) across different levels of study. A structured survey designed to assess knowledge in relation to falls in older people and exercise prescription for falls prevention was administered during second, third and fourth year lectures in seven Australian universities. Students' knowledge was assessed as the percent of correct responses. Overall, 566 students completed the survey and knowledge levels increased significantly with study year. Mean knowledge levels were significantly <70%, indicating limited knowledge. They were lowest for falls risk factor questions and highest for issue/cost related questions in second and third year students. Fourth year students had best knowledge about falls interventions and this was the only group and topic with a mean score >70%. In conclusion, knowledge about falls and exercise prescription for falls prevention in current students does not meet a desired competency level of 70% and is therefore insufficient to ensure an adequately equipped future workforce in this area. There is a clear need for the development and widespread delivery of an evidence-based "exercise for falls prevention" curriculum module for exercise professionals.

Validity and reliability of assessment tools for measuring unsupported sitting in people with a spinal cord injury.

Boswell-Ruys CL, Sturnieks DL, Harvey LA, Sherrington C, Middleton JW, Lord SR

To develop simple tests to assess the abilities of people with spinal cord injury (SCI) to sit unsupported and to assess the construct validity and test-retest reliability of these tests. These simple and quick-to-administer tests have both construct validity and test-retest reliability. They would be appropriate for research and clinical purposes to quantify the abilities of people with SCI to sit unsupported.

The association between choice stepping reaction time and falls in older adults--a path analysis model.

Pijnappels M, Delbaere K, Sturnieks DL, Lord SR

to investigate how physiological and cognitive factors mediate the association between CSRT performance and multiple falls by use of path analysis. this study provides an example of how path analysis can reveal mediators for the association between a functional measure and falls. Our model identified inter-relationships (with relative weights) between physiological and cognitive factors, CSRT and multiple falls.

Impaired weight transfer persists at least four months after hip fracture and rehabilitation.

Nightingale EJ, Sturnieks D, Sherrington C, Moseley AM, Cameron ID, Lord SR

To determine whether choice stepping reaction time performance is impaired in people after hip fracture and whether different aspects of choice stepping performance improve with rehabilitation. Movement deficits are evident for an extended time frame following rehabilitation for hip fracture. The slower response time following the rehabilitation period highlights ongoing difficulties with weight transfer onto the affected leg.

Consequences of lower extremity and trunk muscle fatigue on balance and functional tasks in older people: a systematic literature review.

Helbostad JL, Sturnieks DL, Menant J, Delbaere K, Lord SR, Pijnappels M

Taken together, the findings suggest that balance and functional task performance are impaired with fatigue. Future studies should assess whether fatigue is related to increased risk of falling and whether exercise interventions may decrease fatigue effects.

Relationships between serum vitamin D levels, neuromuscular and neuropsychological function and falls in older men and women.

Menant JC, Close JC, Delbaere K, Sturnieks DL, Trollor J, Sachdev PS, Brodaty H, Lord SR

These findings highlight the associations between vitamin D insufficiency and impairments in physiological and neuropsychological function that predispose older people to fall. The significant relationship between vitamin D insufficiency and falls found in the men may relate to the stronger association found between serum 25OHD levels and dynamic balance measures evident in this male population.

Implementing falls prevention research into policy and practice: an overview of a new National Health and Medical Research Council Partnership Grant.

Lord SR, Delbaere K, Tiedemann A, Smith ST, Sturnieks DL

Preventing falls and fall-related injuries among older people is an urgent public health challenge. This paper provides an overview of the background to and research planned for a 5-year National Health and Medical Research Council Partnership Grant on implementing falls prevention research findings into policy and practice. This program represents a partnership between key Australian falls prevention researchers, policy makers and information technology companies which aims to: (1) fill gaps in evidence relating to the prevention of falls in older people, involving new research studies of risk factor assessment and interventions for falls prevention; (2) translate evidence into policy and practice, examining the usefulness of new risk-identification tools in clinical practice; and (3) disseminate evidence to health professionals working with older people, via presentations, new evidence-based guidelines, improved resources and learning tools, to improve the workforce capacity to prevent falls and associated injuries in the future.

Validity and reliability of the Swaymeter device for measuring postural sway.

Sturnieks DL, Arnold R, Lord SR

The Swaymeter is a reliable tool for assessing postural sway and discriminates between performance of young and older people across multiple sensory conditions.

Effect of wearing a dorsiflexion assist orthosis on mobility, perceived fatigue and exertion during the six-minute walk test in people with multiple sclerosis: a randomised cross-over protocol.

McLoughlin J, Barr C, Sturnieks D, Lord S, Crotty M

Sensorimotor and neuropsychological correlates of force perturbations that induce stepping in older adults.

Sturnieks DL, Menant J, Vanrenterghem J, Delbaere K, Fitzpatrick RC, Lord SR

Inappropriate stepping in response to unexpected balance perturbations is more prevalent in older people and in those at risk of falling. This study examined responses to force-controlled waist pulls in young and older people, and sought to identify physiological and cognitive correlates of the force threshold for stepping. 242 older (79.7±4.2 years) and 15 young (29.5±5.3 years) adults underwent waist pull perturbations and assessments of physiological and neuropsychological functioning, general health and falls efficacy. Perturbation force that induced stepping, stepping strategy and number of steps were measured. The older group withstood less forceful perturbations with a feet-in-place strategy, compared to young. Likewise, older adults with high falls risk withstood less force than those with low risk. After controlling for body weight and gender, sway and lower limb strength were independent predictors of anterior stepping thresholds, reaction time was an independent predictor of posterior thresholds, and executive functioning and lower limb strength were independent predictors of the lateral thresholds. These results suggest that balance, strength and agility training, in addition to cognitive exercises may enhance the ability to withstand unexpected balance perturbations and reduce the risk of falls in older people.

Mild cognitive impairment as a predictor of falls in community-dwelling older people.

Delbaere K, Kochan NA, Close JC, Menant JC, Sturnieks DL, Brodaty H, Sachdev PS, Lord SR

: Incidence of falls in people with cognitive impairment with or without a formal diagnosis of dementia is estimated to be twice that of cognitively intact older adults. This study aimed to investigate whether mild cognitive impairment (MCI) is associated with falls in older people. : The findings indicate that objectively defined MCI is an independent risk factor for injurious or multiple falls in a representative sample of community-dwelling older people. The presence of nonamnestic MCI, based primarily on executive function, was found to be an important factor in increasing fall risk.

The effect of lower limb muscle fatigue on obstacle negotiation during walking in older adults.

Hatton AL, Menant JC, Lord SR, Lo JC, Sturnieks DL

Tripping over obstacles is a common cause of falls in older adults, and muscle fatigue, which can alter walking patterns, may add to this risk. To date, no study has examined the effect of lower limb muscle fatigue on obstacle negotiation in older adults. 30 older adults (13 women, aged 78.3 [6.2] years) negotiated a 12 m obstacle course, while completing a visual secondary task, under two randomized conditions: rested or fatigued. For the fatigue condition, participants performed a repeated sit-to-stand movement, as fast as possible, until they could no longer continue. Participants then immediately began walking trials. Kinematic and kinetic data were collected on approach to, during, and after crossing a height-adjustable target obstacle (10% and 20% of leg length). Repeated measures ANOVA showed a statistically significant increase in lead limb vertical loading rate after stepping over the 10% obstacle when fatigued, relative to rested (P=0.046). No other significant between-condition differences (>0.05) were observed for the other kinematic variables when negotiating the 10% obstacle. Furthermore, no significant between-condition differences (P>0.05) were observed for any kinetic or kinematic variables when negotiating the 20% obstacle. This study describes a feasible method for investigating the consequences of lower limb muscle fatigue on obstacle crossing. The current finding of increased vertical loading rate when fatigued supports the need for further investigation into the effect of muscle fatigue on gait under different environmental conditions, fatiguing a range of muscles, analyzing a more comprehensive array of kinetic and kinematic measures, and in healthy and clinical populations.

Pain and anxiety mediate the relationship between dizziness and falls in older people.

Menant JC, Wong A, Sturnieks DL, Close JC, Delbaere K, Sachdev PS, Brodaty H, Lord SR

To identify medical, psychological, and physiological mediators of the relationship between dizziness and falls in older adults. Suffering from neck and back pain and anxiety were mediators of the relationship between dizziness and falls after controlling for poor sensorimotor function and balance. Older people with dizziness might benefit from interventions targeting these mediators such as pain management and cognitive behavioral therapy.

Angiotensin system-blocking medications are associated with fewer falls over 12 months in community-dwelling older people.

Wong AK, Lord SR, Sturnieks DL, Delbaere K, Trollor JN, Close JC

To investigate relationships between the use of cardiovascular medications, including angiotensin system-blocking medications (ASBMs), orthostatic hypotension (OH), fall risk, and falls in community-dwelling older people. The use of cardiovascular medications in older people did not increase the risk of falls, and the use of ASBMs was associated with lower fall risk. The mechanisms for this apparent protective effect are unclear and appear not to be directly related to muscle strength. More research is required to elucidate the possible protective effects of certain cardiovascular medications in relation to falls in older people.

Force-controlled balance perturbations associated with falls in older people: a prospective cohort study.

Sturnieks DL, Menant J, Delbaere K, Vanrenterghem J, Rogers MW, Fitzpatrick RC, Lord SR

Balance recovery from an unpredictable postural perturbation can be a challenging task for many older people and poor recovery could contribute to their risk of falls. This study examined associations between responses to unpredictable perturbations and fall risk in older people. 242 older adults (80.0 ± 4.4 years) underwent assessments of stepping responses to multi-directional force-controlled waist-pull perturbations. Participants returned monthly falls calendars for the subsequent 12 months. Future falls were associated with lower force thresholds for stepping in the posterior and lateral but not anterior directions. Those with lower posterior force thresholds for stepping were 68% more likely to fall at home than those with higher force thresholds for stepping. These results suggest that amount of force that can be withstood following an unpredictable balance perturbation predicts future falls in community-dwelling older adults. Perturbations in the posterior direction best discriminated between future fallers and non-fallers.

Force-controlled balance perturbations associated with falls in older people: a prospective cohort study.

Sturnieks DL, Menant J, Delbaere K, Vanrenterghem J, Rogers MW, Fitzpatrick RC, Lord SR

Balance recovery from an unpredictable postural perturbation can be a challenging task for many older people and poor recovery could contribute to their risk of falls. This study examined associations between responses to unpredictable perturbations and fall risk in older people. 242 older adults (80.0 ± 4.4 years) underwent assessments of stepping responses to multi-directional force-controlled waist-pull perturbations. Participants returned monthly falls calendars for the subsequent 12 months. Future falls were associated with lower force thresholds for stepping in the posterior and lateral but not anterior directions. Those with lower posterior force thresholds for stepping were 68% more likely to fall at home than those with higher force thresholds for stepping. These results suggest that amount of force that can be withstood following an unpredictable balance perturbation predicts future falls in community-dwelling older adults. Perturbations in the posterior direction best discriminated between future fallers and non-fallers.

Effects of nonslip socks on the gait patterns of older people when walking on a slippery surface.

Hatton AL, Sturnieks DL, Lord SR, Lo JC, Menz HB, Menant JC

Compared with wearing standard socks, wearing nonslip socks improves gait performance and may be beneficial in reducing the risk of slipping in older people.

High arterial pulse wave velocity is a risk factor for falls in community-dwelling older people.

Wong AK, Lord SR, Trollor JN, Sturnieks DL, Delbaere K, Menant J, Brodaty H, Sachdev PS, Close JC

To examine whether arterial stiffness is a risk factor for falls in community-dwelling older people. In community-dwelling older people, high PWV (as a measure of arterial stiffness) was a risk factor for falls after adjusting for potential demographic, anthropometric, disease, and medication confounders. Further research is required to investigate mediators for this association and the effect of lowering arterial stiffness on falls in older people.

Visuospatial tasks affect locomotor control more than nonspatial tasks in older people.

Menant JC, Sturnieks DL, Brodie MA, Smith ST, Lord SR

Compared with nonspatial cognitive tasks, visuospatial cognitive tasks led to a slower, more variable and less smooth gait pattern. These findings suggest that visuospatial processing might share common networks with locomotor control, further supporting the hypothesis that gait changes during dual task paradigms are not simply due to limited attentional resources but to competition for common networks for spatial information encoding.

Gait as a biomarker? Accelerometers reveal that reduced movement quality while walking is associated with Parkinson's disease, ageing and fall risk.

Brodie MA, Lovell NH, Canning CG, Menz HB, Delbaere K, Redmond SJ, Latt M, Sturnieks DL, Menant J, Smith ST, Lord SR

Humans are living longer but morbidity has also increased; threatening to create a serious global burden. Our approach is to monitor gait for early warning signs of morbidity. Here we present highlights from a series of experiments into gait as a potential biomarker for Parkinson's disease (PD), ageing and fall risk. Using body-worn accelerometers, we developed several novel camera-less methods to analyze head and pelvis movements while walking. Signal processing algorithms were developed to extract gait parameters that represented the principal components of vigor, head jerk, lateral harmonic stability, and oscillation range. The new gait parameters were compared to accidental falls, mental state and co-morbidities. We observed: 1) People with PD had significantly larger and uncontrolled anterioposterior (AP) oscillations of the head; 2) Older people walked with more lateral head jerk; and, 3) the combination of vigorous and harmonically stable gait was demonstrated by non-fallers. Our findings agree with research from other groups; changes in human gait reflect changes to well-being. We observed; different aspects of gait reflected different functional outcomes. The new gait parameters therefore may be complementary to existing methods and may have potential as biomarkers for specific disorders. However, further research is required to validate our observations, and establish clinical utility.

Walking for six minutes increases both simple reaction time and stepping reaction time in moderately disabled people with Multiple Sclerosis.

Barr C, McLoughlin J, Lord SR, Crotty M, Sturnieks DL

The aim of this study was to assess the effect of six minutes of walking on simple and choice stepping RT in people with MS. Simple and choice stepping reaction times are slower following six minutes of walking in people with MS. These findings suggest that walking-induced fatigue might lead to central slowing and slowed stepping performance. Further studies are needed to investigate the clinical relevance of these RT measures in relation to fall risk and therapeutic interventions to improve mobility and manage fatigue in people with MS.

Fatigue induced changes to kinematic and kinetic gait parameters following six minutes of walking in people with multiple sclerosis.

McLoughlin JV, Barr CJ, Patritti B, Crotty M, Lord SR, Sturnieks DL

For people with MS, ankle dorsiflexion angle reduces at initial contact following walking induced fatigue, while increased power absorption at the hip, knee and ankle indicate gait inefficiencies that may contribute to higher levels of fatigue and exertion.

Association of Postural Sway with Disability Status and Cerebellar Dysfunction in People with Multiple Sclerosis: A Preliminary Study.

McLoughlin J, Barr C, Crotty M, Lord SR, Sturnieks DL

Participants with MS swayed more and were significantly weaker than controls. Cerebellar dysfunction was identified as the EDSS domain most strongly associated with increased sway, and sensory loss was associated with a relatively greater dependence on vision for balance control. These findings suggest that exercise interventions targeting sensory integration and cerebellar ataxia may be beneficial for enhancing balance control in people with MS.

Age-related changes in gait adaptability in response to unpredictable obstacles and stepping targets.

Caetano MJ, Lord SR, Schoene D, Pelicioni PH, Sturnieks DL, Menant JC

To evaluate age-related changes in gait adaptability in response to obstacles or stepping targets presented at short notice, i.e.: approximately two steps ahead. Compared with their younger counterparts, the older adults exhibited a more conservative adaptation strategy characterised by slow, short and multiple steps with longer time in double support. Even so, they demonstrated poorer stepping accuracy and made more stepping errors. This reduced gait adaptability may place older adults at increased risk of falling when negotiating unexpected hazards.

Visual Field Dependence Is Associated with Reduced Postural Sway, Dizziness and Falls in Older People Attending a Falls Clinic.

Barr CJ, McLoughlin JV, van den Berg ME, Sturnieks DL, Crotty M, Lord SR

Moving visual fields can have strong destabilising effects on balance, particularly when visually perceived motion does not correspond to postural movements. This study investigated relationships between visual field dependence (VFD), as assessed using the roll vection test, and reported dizziness, falls and sway under eyes open, eyes closed and optokinetic conditions. Ninety five falls clinic attendees undertook the roll vection test (i.e. attempted to align a rod to the vertical while exposed to a rotating visual field). Sway was assessed under different visual conditions by centre of pressure movement. Participants also completed questionnaires on space and motion discomfort, fear of falling, depression and anxiety. Thirty four (35.8%) participants exhibited VFD, i.e. had an error > 6.5º in the roll vection test. Compared to participants without VFD, participants with VFD demonstrated less movement of the centre of pressure across all visual conditions, were more likely to report space and motion discomfort and to have suffered more multiple falls in the past year. VFD was independent of fear of falling, anxiety and depression. VFD in a falls clinic population is associated with reduced sway possibly due to a stiffening strategy to maintain stance, dizziness symptoms and an increased risk of falls.

Strength measures are better than muscle mass measures in predicting health-related outcomes in older people: time to abandon the term sarcopenia?

Menant JC, Weber F, Lo J, Sturnieks DL, Close JC, Sachdev PS, Brodaty H, Lord SR

There is no clear consensus on definition, cut-points or standardised assessments of sarcopenia. We found a lower limb strength assessment was at least as effective in predicting balance, mobility and falls in 419 older people as muscle mass-based measures of sarcopenia.

The influence of age, anxiety and concern about falling on postural sway when standing at an elevated level.

Sturnieks DL, Delbaere K, Brodie MA, Lord SR

Psychological processes may influence balance and contribute to the risk of falls in older people. While a self-reported fear of falling is associated with increased postural sway, inducing fear using an elevated platform can lead to reduced sway, suggesting different underlying mechanisms whereby fear may influence balance control. This study examined changes in postural sway, muscle activity and physiological measures of arousal while standing on a 65cm elevated platform, compared to floor level, in young and older adults. The older adults were classified as fall concerned or not fall concerned based on the Falls Efficacy Scale-International and anxious or not anxious based on the Goldberg Anxiety Scale. Fall concern did not affect the physiological and sway response to the elevated platform. In response to the postural threat, the anxious participants increased their sway frequency (p=0.001) but did not reduce sway range (p=0.674). Conversely, non-anxious participants showed an adaptive tightening of balance control, effectively reducing sway range in the elevated condition (p<0.001). Generalised anxiety in older adults appears to differentially affect postural control strategies under threatening conditions.

Sensorimotor and Cognitive Predictors of Impaired Gait Adaptability in Older People.

Caetano MJD, Menant JC, Schoene D, Pelicioni PHS, Sturnieks DL, Lord SR

Superior executive function, fast processing speed, and good muscle strength and balance were all associated with successful gait adaptability. Processing speed appears particularly important for precise foot placements; cognitive capacity for step length adjustments; and early and/or additional cognitive processing involving the inhibition of a stepping pattern for obstacle avoidance. This information may facilitate fall risk assessments and fall prevention strategies.

Tailored multifactorial intervention to improve dizziness symptoms and quality of life, balance and gait in dizziness sufferers aged over 50 years: protocol for a randomised controlled trial.

Menant JC, Migliaccio AA, Hicks C, Lo J, Meinrath D, Ratanapongleka M, Turner J, Sturnieks DL, Delbaere K, Titov N, McVeigh C, Close JC, Lord SR

Transfer effects of step training on stepping performance in untrained directions in older adults: A randomized controlled trial.

Okubo Y, Menant J, Udyavar M, Brodie MA, Barry BK, Lord SR, L Sturnieks D

Step training only in the forward direction improved stepping speed but may acutely slow response times in the untrained diagonal direction. However, this acute effect appears to dissipate after a few repeated step trials. Step training in both forward and lateral directions appears to induce no negative transfer effects in diagonal stepping. These findings suggest home-based step training systems present low risk of harm through negative transfer effects in untrained stepping directions.

Postural stability, falls and fractures in the elderly: results from the Dubbo Osteoporosis Epidemiology Study.

Lord SR, Sambrook PN, Gilbert C, Kelly PJ, Nguyen T, Webster IW, Eisman JA

To assess measures of postural stability in a large population of persons aged over 60 years in order to compare performance between fallers and non-fallers and relate postural stability to fracture prevalence. Tests of postural stability can identify, independently of age, individuals living in the community who are at risk of falls and fall-related fractures.

Physiological factors associated with falls in older community-dwelling women.

Lord SR, Ward JA, Williams P, Anstey KJ

To determine the prevalence of impaired vision, peripheral sensation, lower limb muscle strength, reaction time, and balance in a large community-dwelling population of women aged 65 years and over, and to determine whether impaired performances in these tests are associated with falls. These findings support previous results conducted in retirement village and institutional setting and indicate that the test procedure aids in the identification of older community-dwelling women at risk of falls.

Simple physiological and clinical tests for the accurate prediction of falling in older people.

Lord SR, Clark RD

A 1-year prospective study was conducted in an intermediate care institution to determine whether a combined assessment of physiological and clinical measures discriminates between elderly fallers and elderly nonfallers. Seventy persons aged between 72 and 96 years (mean 85.6), who were generally independent in activities of daily living, took part in the study, and 66 were available to follow-up. In the follow-up year, 24 subjects experienced no falls, 20 subjects fell one time only and 22 residents fell on two or more occasions. Discriminant analysis identified reaction time, body sway, quadriceps strength, tactile sensitivity, gait impairment, cognitive impairment, psychoactive drug use and age as the variables that significantly discriminated between subjects who experienced falls and those who did not. This procedure correctly classified 86% of subjects into faller and nonfaller groups. These findings suggest that an assessment that combines physiological and clinical factors provides excellent discrimination between elderly fallers and nonfallers.

Physiological factors associated with injurious falls in older people living in the community.

Lord SR, McLean D, Stathers G

Performance in six tests of sensorimotor function was measured in 50 subjects who were admitted to an acute hospital because of a fall (ICD codes E880-888), but who did not suffer a fracture of the lower limbs as a result. Performances in these tests were compared with 50 subjects of the same age and sex who had not fallen in the previous 12 months. It was found that those admitted to hospital because of a fall had decreased tactile sensation, reduced quadriceps strength and increased body sway on firm and compliant surfaces. The fallers also performed poorly in clinical tests of static and dynamic balance. Psychoactive-drug use was associated with falling and a number of test measures, including body sway, static balance, dynamic balance and quadriceps strength. Twenty-seven percent of fallers had poor outcomes, in that 1 year after testing, they had either suffered three or more additional falls, been readmitted to hospital, been transferred to nursing homes or died.

Physiological factors associated with falls in an elderly population.

Lord SR, Clark RD, Webster IW

To determine whether a battery of 13 sensorimotor, vestibular, and visual tests discriminates between elderly fallers and elderly non-fallers. It appears that this approach highlights some key physiological factors that predispose elderly individuals to falls.

Postural stability and associated physiological factors in a population of aged persons.

Lord SR, Clark RD, Webster IW

A battery of 13 visual, vestibular, sensorimotor, and balance tests was administered to 95 elderly persons (mean age 82.7 years) to examine the relationships between specific sensorimotor functions and measures of postural stability. When subjects stood on a firm surface, increased body sway was associated with poor tactile sensitivity and poor joint position sense. When subjects stood on a compliant surface (which reduced peripheral sensation) with their eyes open, increased body sway was associated with poor visual acuity and contrast sensitivity, reduced vibration sense, and decreased ankle dorsiflexion strength as well as reduced joint position sense. Increased body sway with eyes closed on the compliant surface was associated with poor tactile sensation, reduced quadriceps and ankle dorsiflexion strength, and increased reaction time. Poor performance in two clinical measures of postural stability was associated with reduced sensation in the lower limbs as measured by joint position sense, tactile sensitivity and vibration sense, reduced quadriceps and ankle dorsiflexion strength, and slow reaction times. The prevalence of vestibular impairments was high in this group, but vestibular function was not significantly associated with sway under any of the test conditions. The results suggest that reduced sensation, muscle weakness in the legs, and increased reaction time are all important factors associated with postural instability. An analysis of the percentage increases in sway under conditions where visual and peripheral sensation systems are removed or diminished, compared with sway under optimal conditions, indicated that peripheral sensation is the most important sensory system in the maintenance of static postural stability.

Use of a physiological profile to document motor impairment in ageing and in clinical groups.

Lord SR, Delbaere K, Gandevia SC

Ability versus hazard: risk-taking and falls in older people.

Butler AA, Lord SR, Taylor JL, Fitzpatrick RC

Assessing behavioral choice in relation to physical ability can identify risk-taking but neither the difficulty of a chosen action nor self-reports of risk-taking behavior are sufficient. Risk-taking behavior is an independent risk factor for falls and management of undue risk-taking might complement existing fall prevention strategies.

Bottom-up subspace clustering suggests a paradigm shift to prevent fall injuries.

Brodie MA, Lovell NH, Redmond SJ, Lord SR

Despite over 10,000 publications since 1990, fall injury rates for older people are still increasing, over and above population ageing. Developing new ways to explore highly dimensional health data and better understand high risk individuals is imperative. The hypothesis investigated is: Falls are a complex multi-systems medical problem. And a paradigm shift in statistical methods is required before fall injuries can be substantially reduced. Here, a new bottom-up supervised subspace clustering (BUSSC) approach suggested as one alternative to conventional approaches. Pilot data were used from 96 community-living older people, 35 with a history of falling. Analysis of variance (ANOVA) found no significant group differences between fallers, and non-fallers. Conversely, BUSSC identified many significant interactions between risk factors that might cause different subgroups of older people to fall. A BUSSC model identified 100% of fallers (Kappa 0.73), comparing favourably to results published from similar populations. BUSSC's superior performance suggests developing new statistical methods should be investigated. Different to previous fall risk models, BUSSC does not require all cases to be classified; instead each cluster provides information most relevant to a homogeneous subgroup of people. However, the three interactions documented may only be small pieces of a larger puzzle. To definitively prove the hypothesis: orders of magnitude more participants should be recruited, prospective falls recorded, and interventions prescribed based on an improved understanding of the individual. A paradigm shift in statistical methods could have profound consequences for health care, allowing us to better understand the individual and focusing less on 'average' population benefit. This knowledge may help develop more individualized treatments for many conditions.

Symmetry matched auditory cues improve gait steadiness in most people with Parkinson's disease but not in healthy older people.

Brodie MA, Dean RT, Beijer TR, Canning CG, Smith ST, Menant JC, Lord SR

To investigate if matching auditory cue a/symmetry to an individual's intrinsic symmetry or asymmetry affects gait steadiness, gait symmetry, and comfort to cues, in people with PD, healthy age-matched controls (HAM) and young. It cannot be assumed all individuals benefit equally from auditory cues. Symmetry matched auditory cues compensated for unsteady gait in most people with PD, but interfered with gait steadiness in older people without basal ganglia deficits.

Effects of a home-based step training programme on balance, stepping, cognition and functional performance in people with multiple sclerosis--a randomized controlled trial.

Hoang P, Schoene D, Gandevia S, Smith S, Lord SR

To determine if step training can improve physical and neuropsychological measures associated with falls in MS. The findings indicate that the step training programme is feasible, safe and effective in improving stepping, standing balance, coordination and functional performance in people with MS.

New Methods to Monitor Stair Ascents Using a Wearable Pendant Device Reveal How Behavior, Fear, and Frailty Influence Falls in Octogenarians.

Brodie MA, Wang K, Delbaere K, Persiani M, Lovell NH, Redmond SJ, Del Rosario MB, Lord SR

Remote analysis of stair ascents is feasible. In our healthy older people, outcomes appeared more related to mental rather than physiological factors. The ascent strategies we observed in some older people may have reflected an appropriate behavioral response to increased concerns about falling.

Use of a physiological profile to document motor impairment in ageing and in clinical groups.

Lord SR, Delbaere K, Gandevia SC

Validity and reliability of a simple 'low-tech' test for measuring choice stepping reaction time in older people.

Delbaere K, Gschwind YJ, Sherrington C, Barraclough E, Garrués-Irisarri MA, Lord SR

To establish the psychometric properties of a simple 'low-tech' choice stepping reaction time test (CSRT-M) by investigating its validity and test-retest reliability. A simple test of unplanned volitional stepping (CSRT-M) has excellent predictive validity for future falls, good inter-day test-retest reliability and excellent criterion validity with respect to the well-validated CSRT-E. The CSRT-M, therefore, may be a useful fall risk screening tool for older people.

Prevalence of Vestibular Disorder in Older People Who Experience Dizziness.

Chau AT, Menant JC, Hübner PP, Lord SR, Migliaccio AA

Dizziness and imbalance are clinically poorly defined terms, which affect ~30% of people over 65 years of age. In these people, it is often difficult to define the primary cause of dizziness, as it can stem from cardiovascular, vestibular, psychological, and neuromuscular causes. However, identification of the primary cause is vital in determining the most effective treatment strategy for a patient. Our aim is to accurately identify the prevalence of benign paroxysmal positional vertigo (BPPV), peripheral, and central vestibular hypofunction in people aged over 50 years who had experienced dizziness within the past year. Seventy-six participants aged 51-92 (mean ± SD = 69 ± 9.5 years) were tested using the head thrust dynamic visual acuity (htDVA) test, dizziness handicap inventory (DHI), as well as sinusoidal and unidirectional rotational chair testing, in order to obtain data for htDVA score, DHI score, sinusoidal (whole-body, 0.1-2 Hz with peak velocity at 30°/s) vestibulo-ocular reflex (VOR) gain and phase, transient (whole-body, acceleration at 150°/s(2) to a constant velocity rotation of 50°/s) VOR gain and time constant (TC), optokinetic nystagmus (OKN) gain, and TC (whole-body, constant velocity rotation at 50°/s). We found that BPPV, peripheral and central vestibular hypofunction were present in 38 and 1% of participants, respectively, suggesting a likely vestibular cause of dizziness in these people. Of those with a likely vestibular cause, 63% had BPPV; a figure higher than previously reported in dizziness clinics of ~25%. Our results indicate that htDVA, sinusoidal (particularly 0.5-1 Hz), and transient VOR testing were the most effective at detecting people with BPPV or vestibular hypofunction, whereas DHI and OKN were effective at only detecting non-BPPV vestibular hypofunction.

Step training improves reaction time, gait and balance and reduces falls in older people: a systematic review and meta-analysis.

Okubo Y, Schoene D, Lord SR

To examine the effects of stepping interventions on fall risk factors and fall incidence in older people. The findings indicate that both reactive and volitional stepping interventions reduce falls among older adults by approximately 50%. This clinically significant reduction may be due to improvements in reaction time, gait, balance and balance recovery but not in strength. Further high-quality studies aimed at maximising the effectiveness and feasibility of stepping interventions are required.

Perceptions of Speed and Risk: Experimental Studies of Road Crossing by Older People.

Butler AA, Lord SR, Fitzpatrick RC

Crossing a road safely is a complex task requiring good sensorimotor function and integration of information about traffic speed, distances and one's own speed. Poor judgement through age-related sensorimotor or cognitive impairment or a predisposition to take risks could lead to errors with serious consequences. On a simulated road, 85 participants (age ≥70 years) were asked to cross in front of an approaching car with a clearance as small as considered safe in two conditions; (1) with nothing else to attend to (free crossing) and (2) with an additional ball-gathering task while waiting to cross (task crossing). Participants were categorised according to their crossing outcome (failed to cross, 'hit', exact, safe, cautious). Participants also performed two sub-studies; (1) the perception of the time-to-arrival of moving objects and (2) the perception of own gait speed. Physical and cognitive function and everyday risk-taking behaviour were also assessed. In free crossing, clearances varied but no participants were "hit" by the car. In task crossing, participants allowed smaller clearances and 10% of participants would have been hit while 13% missed the opportunity to cross altogether. Across a wide range of physical and cognitive measures, including perceived and actual gait speed, a consistent pattern was observed in the task crossing condition. The exact group performed best, the 'hit', safe and cautious groups performed less well while those who missed the opportunity (fail) performed worst. The exact group reported taking the greatest risks in everyday life whereas the remaining groups reported being cautious. In conclusion, we found older people with poorer perceptual, physical and cognitive function made inappropriate and risky decisions in a divided attention road-crossing task despite self-reports of cautious behaviour in everyday life.