A taxonomy of cognitive tasks to evaluate cognitive-motor interference on spatiotemoporal gait parameters in older people: a systematic review and meta-analysis.

BACKGROUND: Walking in natural environments can be considered a dual-task (DT) scenario that requires increasing cognitive resources with advancing age. Previous reviews concluded that gait speed under DT conditions is equivalent to gait speed as a single task (ST) in the prediction of future falls in older people. However, without a clear taxonomy, these conclusions might be premature. The aim of this review is to use a taxonomy for classifying cognitive tasks of cognitive-motor interference (CMI) paradigms while walking to identify which task domains lead to more pronounced cognitive-motor decrements due to fall risk and concern about falling (CoF) in older people. METHODS: A systematic literature research following PRISMA guidelines was conducted using MEDLINE, Psych-Info and EMBASE. Inclusion criteria were: older people ≥60 years with a previous fall or CoF, use of a DT paradigm to discriminate fallers and non-fallers, straight overground walking, reported gait measurements during ST and DT conditions. A meta-analysis estimated the effect of DT costs for the cognitive task domain and spatiotemporal gait parameters. RESULTS: N = 3737 studies were found within the databases. Nineteen studies were included (n = 14 for meta-analysis). Fallers and people with CoF showed reduced walking speed for ST and DT conditions. Effects of DT were examined for mental tracking tasks. The combined odds ratio (OR [95% confidence interval]) for fallers vs. non-fallers for ST was 3.13 [0.47, 5.80] with moderate heterogeneity (I 2 = 48%). For DT, the OR was 5.17 [2.42, 7.93] with low heterogeneity (I 2 = 37%). Comparing participants with and without CoF, the OR for ST was 12.41 [9.97, 14.84] with high heterogeneity (I 2 = 85%) and OR for mental tracking DT was 10.49 [7.58, 13.40] with moderate heterogeneity (I 2 = 51%). CONCLUSION: CMI was not significantly different between fallers and non-fallers or people with and without CoF; however, our taxonomy revealed a large variety of cognitive conditions and a higher number of studies using mental tracking tasks, which make it impossible to draw firm conclusions. Future studies should use a more standardised and ecologically valid approach when evaluating the validity of DT gait performance in the prediction of falls, CoF or other age-related conditions. TRIAL REGISTRATION: This review was registered at Prospero with the ID: CRD42017068912.

Does dual task training improve walking performance of older adults with concern of falling?

BACKGROUND: Older adults with concerns of falling show decrements of gait stability under single (ST) and dual task (DT) conditions. To compare the effects of a DT training integrating task managing strategies for independent living older adults with and without concern about falling (CoF) to a non-training control group on walking performance under ST and DT conditions. METHODS: Single center parallel group single blind randomized controlled trial with group-based interventions (DT-managing balance training) compared to a control group (Ninety-five independent living older adults; 71.5 ± 5.2 years). A progressive DT training (12 sessions; 60 min each; 12 weeks) including task-managing strategies was compared to a non-training control group. SETTING: group based intervention for independent living elderly in a gym. ST and DT walking (visual verbal Stroop task) were measured on a treadmill. Gait parameters (step length, step width, and gait line) and cognitive performance while walking were compared with a 2x2x2 Repeated Measures Analyses of Variance. RESULTS: Participants in the intervention group showed an increased step length under ST and DT conditions following the intervention, for both people with and without CoF compared to their respective control groups. Foot rolling movement and cognitive performance while walking however only improved in participants without CoF. CONCLUSIONS: The results showed that DT managing training can improve walking performance under ST and DT conditions in people with and without CoF. Additional treatment to directly address CoF, such as cognitive behavioural therapy, should be considered to further improve the cautious gait pattern (as evidenced by reduced foot rolling movements). TRIAL REGISTRATION: The study was retrospectively registered in the German Clinical Trials Register (DRKS; Identification number DRKS00012382 , 11.05.2017).

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

OBJECTIVE: 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. DESIGN: Cross-sectional. SETTING: Community. SUBJECTS: A total of 169 older people from the control arm of a clinical trial and a convenience sample of 30 older people. MAIN MEASURES: Demographic, physical, cognitive and prospective falls data were collected in addition to CSRT-M. The CSRT-M time was taken as the total time to complete 20 steps onto four targets printed on a portable rubber mat. Assessment of the original electronic version (CSRT-E) and re-administration of the CSRT-M the next day was done in 30 participants. RESULTS: Multivariate regression analysis showed that the CSRT-M time was best explained by leaning balance control, quadriceps strength and cognitive functioning (R2 = 0.44). Performance on the CSRT-M was worse in older participants and participants with a presence of fall risk factors, supporting good discriminant validity. The odds of suffering multiple future falls increased by 74% (odds ratio (OR) = 1.74, 95% CI (confidence interval) = 1.14-2.65, p = 0.010) for each standard deviation increase in CSRT-M, supporting good predictive validity. Criterion validity was confirmed by a strong bivariate correlation between CSRT-M and CSRT-E (0.81, p < 0.001). Test-retest reliability for the CSRT-M was good (intraclass correlation coefficient = 0.74, 95% CI = 0.45-0.88, p < 0.001). CONCLUSIONS: 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.

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

Ageing decreases exercise performance and is frequently accompanied by reductions in cognitive performance. Deterioration in the physiological capacity to stand, locomote and exercise can manifest itself as falling over and represents a significant deterioration in sensorimotor control. In the elderly, falling leads to serious morbidity and mortality with major societal costs. Measurement of a suite of physiological capacities that are required for successful motor performance (including vision, muscle strength, proprioception and balance) has been used to produce a physiological profile assessment (PPA) which has been tracked over the age spectrum and in different diseases (e.g. multiple sclerosis, Parkinson's disease). As well as measures of specific physiological capacities, the PPA generates an overall 'score' which quantitatively measures an individual's cumulative risk of falling. The present review collates data from the PPA (and the physiological capacities it measures) as well as its use in strategies to reduce falls in the elderly and those with different diseases. We emphasise that (i) motor impairment arises via reductions in a wide range of sensorimotor abilities; (ii) the PPA approach not only gives a snapshot of the physiological capacity of an individual, but it also gives insight into the deficits among groups of individuals with particular diseases; and (iii) deficits in seemingly restricted and disparate physiological domains (e.g. vision, strength, cognition) are funnelled into impairments in tasks requiring upright balance. Motor impairments become more prevalent with ageing but careful physiological measurement and appropriate interventions offer a way to maximise health across the lifespan.

Evaluating the effectiveness of a home-based exercise programme delivered through a tablet computer for preventing falls in older community-dwelling people over 2†years: study protocol for the Standing Tall randomised controlled trial.

INTRODUCTION: In order to prevent falls, older people should exercise for at least 2 h per week for 6 months, with a strong focus on balance exercises. This article describes the design of a randomised controlled trial to evaluate the effectiveness of a home-based exercise programme delivered through a tablet computer to prevent falls in older people. METHODS AND ANALYSIS: Participants aged 70 years or older, living in the community in Sydney will be recruited and randomly allocated to an intervention or control group. The intervention consists of a tailored, home-based balance training delivered through a tablet computer. Intervention participants will be asked to complete 2 h of exercises per week for 2 years. Both groups will receive an education programme focused on health-related information relevant to older adults, delivered through the tablet computer via weekly fact sheets. Primary outcome measures include number of fallers and falls rate recorded in weekly fall diaries at 12 months. A sample size of 500 will be necessary to see an effect on falls rate. Secondary outcome measures include concern about falling, depressive symptoms, health-related quality of life and physical activity levels (in all 500 participants); and physiological fall risk, balance, functional mobility, gait, stepping and cognitive performance (in a subsample of 200 participants). Adherence, acceptability, usability and enjoyment will be recorded in intervention group participants over 2 years. Data will be analysed using the intention-to-treat principle. Secondary analyses are planned in people with greater adherence. Economic analyses will be assessed from a health and community care provider perspective. ETHICS AND DISSEMINATION: Ethical approval was obtained from UNSW Ethics Committee in December 2014 (ref number HC#14/266). Outcomes will be disseminated through publication in peer-reviewed journals and presentations at international conferences. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (ACTRN)12615000138583.

Development of a standard fall data format for signals from body-worn sensors : the FARSEEING consensus.

Objective measurement of real-world fall events by using body-worn sensor devices can improve the understanding of falls in older people and enable new technology to prevent, predict, and automatically recognize falls. However, these events are rare and hence challenging to capture. The FARSEEING (FAll Repository for the design of Smart and sElf-adapaive Environments prolonging INdependent livinG) consortium and associated partners strongly argue that a sufficient dataset of real-world falls can only be acquired through a collaboration of many research groups. Therefore, the major aim of the FARSEEING project is to build a meta-database of real-world falls. To establish this meta-database, standardization of data is necessary to make it possible to combine different sources for analysis and to guarantee data quality. A consensus process was started in January 2012 to propose a standard fall data format, involving 40 experts from different countries and different disciplines working in the field of fall recording and fall prevention. During a web-based Delphi process, possible variables to describe participants, falls, and fall signals were collected and rated by the experts. The summarized results were presented and finally discussed during a workshop at the 20th Conference of the International Society of Posture and Gait Research 2012, in Trondheim, Norway. The consensus includes recommendations for a fall definition, fall reporting (including fall reporting frequency, and fall reporting variables), a minimum clinical dataset, a sensor configuration, and variables to describe the signal characteristics.

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

UNLABELLED: Among 463 community dwellers aged 70-90 years, those with vitamin D insufficiency showed reduced neuromuscular function, balance control and stepping ability and performed worse in tests of cognitive function. In men, vitamin D insufficiency was associated with an increased risk of falling. INTRODUCTION: The purpose of this study was to investigate the relationship between serum 25-hydroxy vitamin D (serum 25OHD) levels, physiological and neuropsychological function in older people, and to examine the relationship between serum 25OHD and prospective falls. METHODS: Four hundred sixty-three community-dwelling people aged 70-90 years underwent an assessment of physiological and neuropsychological performance and structured interviews relating to comorbidity and disability. Fall frequency during the 12 months follow-up was monitored with monthly falls diaries. RESULTS: Twenty-one percent of the men and 44% of the women were vitamin D insufficient (serum 25OHD ≤ 50 nmol/L). Participants with vitamin D insufficiency had weaker upper and lower limb strength, slower simple finger press and choice stepping reaction time, poorer leaning balance and slower gait speed, after controlling for age and body mass index, and, poorer executive function and visuospatial ability, after controlling for age and education. Vitamin D insufficiency significantly increased the rate of falls in men (IRR = 1.94, 95% CI = 1.19-3.15, p = 0.008) but not in women. CONCLUSIONS: 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.

Relationships between HMG-CoA reductase inhibitors (statin) use and strength, balance and falls in older people.

AIMS: To investigate associations between HMG-CoA reductase inhibitor (statin) use and muscle strength, balance, mobility and falls in older people. METHODS: Five hundred community-dwelling people aged 70-90 years provided information about their medication use and undertook tests of lower limb strength, postural sway, leaning balance (maximal balance range and coordinated stability tests) and functional mobility. Participants were then followed up for 12 months with respect to falls. RESULTS: After adjusting for general health in analyses of covariance procedures, statin users had poorer maximal balance range than non-statin users (P = 0.017). Statin and non-statin users did not differ with respect to strength, postural sway, mobility or falls experienced in the follow-up year. CONCLUSION: In a sample of healthy older people, statin use was not associated with muscle weakness, postural sway, reduced mobility or falls. Statin users, however, had poorer leaning balance which may potentially increase fall risk in this group.

A Falls Concern Scale for people with spinal cord injury (SCI-FCS).

STUDY DESIGN: Observational study and cross-sectional survey. OBJECTIVES: To develop a scale assessing concern about falling in people with spinal cord injuries who are dependent on manual wheelchairs, and to evaluate psychometric properties of this new scale. SETTING: Community and hospitals, Australia. METHODS: The Spinal Cord Injury-Falls Concern Scale (SCI-FCS) was developed in consultation with SCI professionals. The SCI-FCS addressed concern about falling during 16 activities of daily living associated with falling and specific to people with SCI. One hundred and twenty-five people with either acute or chronic SCI who used manual wheelchairs were assessed on the SCI-FCS and asked questions related to their SCI and overall physical abilities. A subgroup of 20 people was reassessed on the SCI-FCS within 7 days. RESULTS: The SCI-FCS had excellent internal and test-retest reliability (Cronbach's alpha=0.92, intra-class correlation coefficient (ICC)=0.93). Factor analysis revealed three underlying dimensions of the SCI-FCS addressing concern about falling during activities that limit hand support and require movement of the body's centre of mass. The discriminative ability of the SCI-FCS between different diagnostic groups indicated good construct validity. Subjects with a high level of SCI, few previous falls, dependence in vertical transfers and poor perceived sitting ability demonstrated high levels of concern about falling. CONCLUSIONS: This study suggests that the SCI-FCS is a valid and reliable tool for assessing concern about falling in people with SCI dependent on manual wheelchairs. The SCI-FCS could also assist in determining the effectiveness of fall minimization programs.

Evaluation of the incidental and planned activity questionnaire (IPEQ) for older people.

OBJECTIVE: There is a need for a measure of physical activity that assesses low, basic and high-intensity activities suitable for use in ageing research including falls prevention trials. This study performed a formal validation of the incidental and planned activity questionnaire (IPEQ) by investigating its overall structure and measurement properties. DESIGN: Cross-sectional survey. SETTING: Community sample. PARTICIPANTS: 500 older people (mean age 77.4 years, SD 6.08). MAIN OUTCOME MEASURES: The IPEQ was administered as part of a longer assessment in two different postal self-completion formats; one for estimating physical activity during the past week (IPEQ-W) and one for estimating average weekly physical activity over the past 3 months (IPEQ-WA). Test-retest reliability was assessed by the re-administration of the instruments one week later in a subsample of 80 respondents. RESULTS: Both IPEQ versions had good measurement properties, but overall the IPEQ-WA performed better than the IPEQ-W. Rasch analyses indicated the IPEQ-WA had an excellent overall fit. Analysis of the internal structure supported the unidimensionality of the scale with an acceptable internal consistency. The content representation of the items revealed three categories (low, moderate and high levels of physical activity), with a good contribution of items by threshold. The IPEQ-WA had excellent test-retest reliability, intraclass correlation coefficient 0.87) and was able to discriminate differences in physical activity levels between groups differentiated by sex, age and fall risk factors. CONCLUSIONS: The IPEQ has excellent psychometric properties and assesses the level of physical activity relating to both basic and more demanding activities. Further research is required to confirm sensitivity to change.

A prospective study of gait related risk factors for exercise-related lower leg pain.

The purpose of this study was to determine prospectively gait related risk factors for exercise-related lower leg pain (ERLLP) in 400 physical education students. Static lower leg alignment was determined, and 3D gait kinematics combined with plantar pressure profiles were collected. After this evaluation, all sports injuries were registered by the same sports physician during the duration of the study. Forty six subjects developed ERLLP and 29 of them developed bilateral symptoms thus giving 75 symptomatic lower legs. Bilateral lower legs of 167 subjects who developed no injuries in the lower extremities served as controls. Cox regression analysis revealed that subjects who developed ERLLP had an altered running pattern before the injury compared to the controls and included (1) a significantly more central heel-strike, (2) a significantly increased pronation, accompanied with more pressure underneath the medial side of the foot, and (3) a significantly more lateral roll-off. These findings suggest that altered biomechanics play a role in the genesis of ERLLP and thus should be considered in prevention and rehabilitation.

A home-based multidimensional exercise program reduced physical impairment and fear of falling.

OBJECTIVE: To investigate the efficacy of a guided and graded home-based exercise program for improving a range of physical outcomes in older people. DESIGN: Controlled clinical trial of 16 weeks. SETTING: Two geographical areas in Gent, Belgium. PARTICIPANTS: 66 independent-living older people (age: 71-98) with a history of falls and moderate physical impairment. INTERVENTION: Twenty-four 30-minute training sessions were given by a trained physiotherapist over a period of 16 weeks in the participant's home. Different types of exercises on balance, aerobic performance, flexibility, and muscle strength were provided. MAIN OUTCOME MEASURES: Muscle strength, static and dynamic balance, aerobic performance, activities in daily living, fear of falling and avoidance of daily activities were assessed at baseline and after 16 weeks intervention. RESULTS: At baseline, there were no significant differences in the measured variables between exercise and control groups. After 16 weeks, the exercise group showed significantly improved ankle muscle strength, balance performance and aerobic capacity, and decreased fear of falling, dependency in daily activities and avoidance of daily activities compared to the control group. The improvements in knee muscle strength, timed chair stands, and functional reach were not significant. CONCLUSION: The home-based, individualized exercise program was effective in reducing several physical factors associated with falls in community-dwelling older people with moderate physical impairment. The decrease in fear of falling and other behavioural variables needs to be considered with care and needs further investigation.

Intrinsic risk factors for inversion ankle sprains in females--a prospective study.

Ankle sprains are extremely common. However, very little is known about the variables that predispose individuals to these injuries. The purpose of this study was to examine prospectively intrinsic risk factors for inversion sprains in a young physically active female population. One hundred and fifty-nine female physical education students were evaluated for several possible intrinsic risk factors for inversion sprains at the beginning of their academic study. The evaluated intrinsic risk factors included anthropometrical and physical characteristics, ankle joint position sense, isokinetic ankle muscle strength, lower leg alignment characteristics, postural control and muscle reaction time during a sudden inversion perturbation. All sports injuries were registered during 1-3 years and exposure to sport was recorded (mean: 15.33+/-4.33 h a week). Thirty-two (20%) of the 159 females sprained their ankle. The number of ankle sprains per 1000 h of sports exposure was 0.75. The Cox regression analysis revealed that females with less accurate passive joint inversion position sense [hazard ratio (HR): 1.08, 95% confidence interval (CI): 1.02-1.14 for absolute error at 15 degrees inversion], a higher extension range of motion at the first metatarsophalangeal joint (HR: 1.03, 95% CI: 1.00-1.06) and less coordination of postural control (HR: 0.96, 95% CI: 0.93-1.00 for endpoint excursion; HR: 0.94, 95% CI: 0.89-0.99 for maximal endpoint excursion) are at greater risk of an ankle sprain. The findings of this study suggest that effective prevention and conservative rehabilitation of ankle inversion sprains should include attention to these variables.

Relationship between gait biomechanics and inversion sprains: a prospective study of risk factors.

This prospective study determined gait related risk factors for inversion sprains in 223 physical education students. Static lower leg alignment was determined, and 3D-kinematics combined with plantar pressure profiles were collected. After evaluation, the same sports physician registered all sports injuries during the next 6-18 months. During this period, 21 subjects had an inversion sprain, one of whom had a bilateral sprain. Twenty-two ankles, 12 left and 10 right comprised the inversion sprain group and both feet of 36 non-injured subjects acted as controls. Comparison of the two groups revealed that the gait of subjects who are at risk of sustaining an inversion sprain had a laterally situated centre of pressure at initial contact. These subjects also showed a mobile foot type at first metatarsal contact, forefoot flat and heel off. In this type the foot is more pronated over a prolonged period and accompanied by more pressure underneath the medial side of the foot and a delayed maximal knee flexion. Resupination is delayed and roll off does not occur across the hallux, but more laterally, probably because of the diminished support at the first metatarsophalangeal joint. Total foot contact time was also longer in the inversion sprain group compared with controls. The findings of this study suggest that effective prevention and rehabilitation of inversion sprains should include attention to gait patterns and adjustments of foot biomechanics.