Ladder Use Ability, Behavior and Exposure by Age and Gender.

This study aimed to quantify and compare ladder use ability and behavior in younger and older men and women from three ladder use behavior experiments. The experimental tasks comprised (1) changing a lightbulb on a household stepladder under two cognitive demands (single and dual task), (2) clearing a simulated roof gutter on a straight ladder and (3) querying ladder choice in different exigency scenarios. Ladder use ability and behavior data were captured from recorded time, performance, motion capture and user choice data. In addition, this study surveyed ladder use frequency and habitual behaviors. The experimental findings indicate that older adults require more time to complete ladder tasks; younger adults display riskier ladder use behaviors; men and women display similar ladder use ability; and men are more willing to climb riskier ladders. The survey found older adults to report more frequent ladder use than younger adults, and men use straight ladders more frequently than women. These results suggest that the reported higher ladder fall rates experienced by older adults and men are linked to increased ladder use exposure and riskier ladder choice. This knowledge can help guide population-specific interventions to reduce ladder falls in both young and older people.

Brain and brawn in balance: Central processing speed and muscle torque development speed are independently associated with the ability to recover balance with feet-in-place.

BACKGROUND: Stepping thresholds, i.e. the maximum perturbation one can withstand without taking a step, predict falls in older people. This ability requires fast central processing of sensory information followed by rapid execution of adequate motor responses, both of which are affected by age. However, there is limited evidence on their combined effect on stepping thresholds. RESEARCH QUESTION: Are cognitive and motor speeds important for stepping thresholds and do they interact, allowing for compensation? METHODS: Two-hundred forty-two people (mean age: 80 years, standard deviation 4; 110 women) underwent a series of waist-pulls of increasing magnitude to assess stepping thresholds in anterior, posterior and mediolateral directions. Cognitive function was assessed as simple hand reaction time and trail making test performance, and muscle function was assessed as isometric peak and rate of torque development of dominant leg muscles. Principal component analysis reduced these variables to four factors: peak muscle strength, muscle torque development speed (motor speed), executive function and central processing speed (cognitive speed). These factors were used in univariable and multivariable regression models to determine their association with stepping thresholds. RESULTS: Faster central processing speed (beta:2.69; 95 %CI:1.49-3.88) and faster muscle torque development speed (beta:2.60, 95 %CI:0.63-4.57) were associated with higher stepping thresholds. These associations remained in a multivariable model. No interaction was found between cognitive and motor speed on stepping thresholds (p = 0.602). SIGNIFICANCE: Central processing speed and muscle torque development speed affect stepping thresholds independently from each other and may both be important age-related motor impairment targets for preventing falls in older people.

Treadmill induced belt-accelerations may not accurately evoke the muscle responses to obstacle trips in older people.

BACKGROUND: Treadmill belt-accelerations are a commonly utilised surrogate for tripping, but their physiological validity is unknown. This study examined if a treadmill belt-acceleration induces lower limb muscle activation responses similar to a trip on a walkway. METHODS: 38 older people (65+ years) experienced one treadmill belt-acceleration and one walkway obstacle trip in random order. Muscle responses were assessed bilaterally using surface electromyography on the rectus femoris (RF), tibialis anterior (TA), semitendinosus (ST) and gastrocnemius medial head (GM). Unperturbed muscle activity, post-perturbation onset latency, peak magnitude, time to peak and co-contraction index (CCI) were examined. RESULTS: Muscle activity in the right ST was greater during unperturbed walking on the treadmill compared to walkway (P=0.011). Compared to a treadmill belt-acceleration, a walkway trip elicited faster onset latencies in all muscles; greater peak magnitudes in the left RF, TA, GM and right GM; faster time to peaks in the left TA and right GM; and lower knee and ankle muscle CCI (P<0.05). CONCLUSIONS: Walkway trips and treadmill belt-accelerations elicit distinct muscle activation patterns. While walkway trips induced faster and larger muscle responses, treadmill belt-accelerations involved greater co-contraction. Therefore, treadmill belt-accelerations may not accurately simulate the muscle responses to trips.

A custom-built step exergame training programme to prevent falls in people with multiple sclerosis: A multicentre randomised controlled trial.

BACKGROUND: Cognitive-motor step training can improve stepping, balance and mobility in people with multiple sclerosis (MS), but effectiveness in preventing falls has not been demonstrated. OBJECTIVES: This multisite randomised controlled trial aimed to determine whether 6 months of home-based step exergame training could reduce falls and improve associated risk factors compared with usual care in people with MS. METHODS: In total, 461 people with MS aged 22-81 years were randomly allocated to usual care (control) or unsupervised home-based step exergame training (120 minutes/week) for 6 months. The primary outcome was rate of falls over 6 months from randomisation. Secondary outcomes included physical, cognitive and psychosocial function at 6 months and falls over 12 months. RESULTS: Mean (standard deviation (SD)) weekly training duration was 70 (51) minutes over 6 months. Fall rates did not differ between intervention and control groups (incidence rates (95% confidence interval (CI)): 2.13 (1.57-2.69) versus 2.24 (1.35-3.13), respectively, incidence rate ratio: 0.96 (95% CI: 0.69-1.34, p = 0.816)). Intervention participants performed faster in tests of choice-stepping reaction time at 6 months. No serious training-related adverse events were reported. CONCLUSION: The step exergame training programme did not reduce falls among people with MS. However, it significantly improved choice-stepping reaction time which is critical to ambulate safely in daily life environment.

Effect of cognitive training on cognitive function in community-dwelling older people with mild-to-moderate dementia: A single-blind randomised controlled trial.

OBJECTIVES: The purpose of this assessor-blinded, randomised controlled trial was to determine the effect of computerised cognitive training (CT) on executive function, processing speed and working memory in 61 people with mild-to-moderate dementia. METHODS: The primary outcomes were forward Digit Span and Trail Making Tests (TMT) at the completion of the 6-month intervention. Secondary outcomes included cognitive and physical performance, rate of falls, participant and caregiver's quality of life and usability and adherence to the CT program. The study was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12617000364370). RESULTS: Intervention group (n = 31) participants averaged 81 min of CT per week, and system usability scores were acceptable (participants: 68.8 ± 22.1; caregivers: 79.4 ± 23.5). There were no statistically significant differences in cognitive or physical performance outcomes between the intervention and control groups at 6- or 12-months (between-group differences [95% CI] for primary outcomes at 6-months: Forward Digit Span -0.3 [-0.8, 0.3]; TMT-A 2.7 s [-14.1, 19.5]; TMT-B -17.1 s [-79.3, 45.2]). At the 12-month follow-up reassessment, the intervention group reported significantly more depressive symptoms and had lower caregiver-rated participant quality of life and higher caregiver quality of life compared to control. CONCLUSIONS: This study showed no benefit of the CT program on working memory, processing speed and executive function. Future studies are required to better understand how CT can be used to improve cognitive and physical functioning in older people with mild-moderate dementia.

Poor mobility and lower limb weakness are associated with three distinct depressive symptom trajectories over 6 years in older people.

OBJECTIVES: Physical decline can be associated with the onset of depressive symptoms in later life. This study aimed to identify physical and lifestyle risk factors for depressive symptom trajectories in community-dwelling older adults. METHODS: Participants were 553 people aged 70-90 years who underwent baseline physical, psychological and lifestyle assessments. Group-based trajectory analysis was used to identify patterns of depressive symptom development over 6 years of follow-up. Strengths of associations between baseline functional test performances and depressive symptom trajectories were evaluated with univariable ordinal models. Subsequently, the adjusted cumulative odds ratio for the association between identified risk factors, demographic factors and baseline anti-depressant use were measured using multivariable ordinal logistic regression. RESULTS: Three distinct depressive symptom trajectories were identified: a low-and-stable course (10% of participants), a low-and-increasing course (81%) and a moderate-and-increasing course (9%). Timed Up and Go test time was the strongest risk factor of depressive symptom trajectory, followed by Five Times Sit-to-Stand test performance, planned physical activity levels, and knee extension strength (adjusted standardised ORs 1.65, 95% CI 1.34-2.04; 1.44, 95% CI 1.16-1.77; 1.44, 95% CI 1.17-1.76 and 1.41, 95% CI 1.15-1.73 respectively). After adjusting for age, sex, body mass index and baseline anti-depressant use, Timed Up and Go test performance and knee extension strength were independently and significantly associated with depressive trajectories. CONCLUSIONS: Timed Up and Go test times, Five Times Sit-to-Stand test performance, planned physical activity levels and knee extension strength are associated with three discrete depressive symptom trajectories. These clinical tests may help identify older adults aged 70-90 years at risk of developing depressive symptoms and help guide subsequent strength and mobility interventions.

Exergame and cognitive training for preventing falls in community-dwelling older people: a randomized controlled trial.

Exergame training, in which video games are used to promote exercise, can be tailored to address cognitive and physical risk factors for falls and is a promising method for fall prevention in older people. Here, we performed a randomized clinical trial using the smart±step gaming system to examine the effectiveness of two home-based computer game interventions, seated cognitive training and step exergame training, for fall prevention in community-dwelling older people, as compared with a minimal-intervention control group. Participants aged 65 years or older (n = 769, 71% female) living independently in the community were randomized to one of three arms: (1) cognitive training using a computerized touchpad while seated, (2) exergame step training on a computerized mat or (3) control (provided with an education booklet on healthy ageing and fall prevention). The rate of falls reported monthly over 12 months-the primary outcome of the trial-was significantly reduced in the exergame training group compared with the control group (incidence rate ratio = 0.74, 95% confidence interval = 0.56-0.98), but was not statistically different between the cognitive training and control groups (incidence rate ratio = 0.86, 95% confidence interval = 0.65-1.12). No beneficial effects of the interventions were found for secondary outcomes of physical and cognitive function, and no serious intervention-related adverse events were reported. The results of this trial support the use of exergame step training for preventing falls in community-dwelling older people. As this intervention can be conducted at home and requires only minimal equipment, it has the potential for scalability as a public health intervention to address the increasing problem of falls and fall-related injuries. Australian and New Zealand Clinical Trial Registry identifier: ACTRN12616001325493 .

Cognitive and physical declines and falls in older people with and without mild cognitive impairment: a 7-year longitudinal study.

OBJECTIVES: We examined longitudinal changes in cognitive and physical function and associations between change in function and falls in people with and without mild cognitive impairment (MCI). DESIGN: Prospective cohort study with assessments every 2 years (for up to 6 years). SETTING: Community, Sydney, Australia. PARTICIPANTS: Four hundred and eighty one people were classified into three groups: those with MCI at baseline and MCI or dementia at follow-up assessments (n = 92); those who fluctuated between cognitively normal and MCI throughout follow-up (cognitively fluctuating) (n = 157), and those who were cognitively normal at baseline and all reassessments (n = 232). MEASUREMENTS: Cognitive and physical function measured over 2-6 years follow-up. Falls in the year following participants' final assessment. RESULTS: In summary, 27.4%, 38.5%, and 34.1% of participants completed 2, 4, and 6 years follow-up of cognitive and physical performance, respectively. The MCI and cognitive fluctuating groups demonstrated cognitive decline, whereas the cognitively normal group did not. The MCI group had worse physical function than the cognitively normal group at baseline but decline over time in physical performance was similar across all groups. Decline in global cognitive function and sensorimotor performance were associated with multiple falls in the cognitively normal group and decline in mobility (timed-up-and-go test) was associated with multiple falls across the whole sample. CONCLUSIONS: Cognitive declines were not associated with falls in people with MCI and fluctuating cognition. Declines in physical function were similar between groups and decline in mobility was associated with falls in the whole sample. As exercise has multiple health benefits including maintaining physical function, it should be recommended for all older people. Programs aimed at mitigating cognitive decline should be encouraged in people with MCI.

Combined Reactive and Volitional Step Training Improves Balance Recovery and Stepping Reaction Time in People With Parkinson's Disease: A Randomised Controlled Trial.

BACKGROUND: Falls are frequent and devastating events for people with Parkinson's disease (PD). Here, we investigated whether laboratory-based reactive step training combined with home-based volitional step training was effective in improving balance recovery and stepping ability in people with PD. METHODS: Forty-four people with idiopathic PD were randomized into intervention or control groups. Intervention participants performed unsupervised volitional step training using home-based exergames (80+ minutes/week) for 12 weeks and attended reactive step training sessions in which they were exposed to slip and trip perturbations at 4 and 8 weeks. Control participants continued their usual activities. Primary outcomes were balance recovery following an induced-trip/slip and choice stepping reaction time (CSRT) at the 12-week reassessment. Secondary outcomes comprised sensorimotor, balance, cognitive, psychological, complex stepping (inhibitory CSRT and Stroop Stepping Test [SST]), gait measures, and falls experienced in everyday life. RESULTS: At reassessment, the intervention group had significantly fewer total laboratory-induced falls and faster CSRT compared to the control group (P < .05). The intervention group also had significantly faster inhibitory CSRT and SST movement times and made fewer mistakes in the SST (P < .05). There were no significant differences in the rate of every day falls or other secondary outcome measures between the groups. CONCLUSION: Combined volitional and reactive step training improved balance recovery from an induced-perturbation, voluntary stepping time, and stepping accuracy in cognitively challenging tests in people with PD. Further research is required to determine whether such combined step training can prevent daily-life falls in this population.

Risk Factors for Falls and Fall-Related Fractures in Community-Living Older People with Pain: A Prospective Cohort Study.

(1) Background: This prospective study aimed to identify predictors of falls and fall-related fractures in community-dwelling older people with pain; (2) Methods: Participants comprised 389 community-dwelling older people aged 70+ years who had musculoskeletal pain in the neck, back, hip, leg/knee and/or feet. Demographic, anthropometric, balance, mobility, cognitive function, psychological status and physical activity level measures were obtained at baseline. Falls were monitored with monthly falls calendars for 12 months. Logistic regression analyses were performed to identify predictors of falls and fall-related fractures during a 12-month follow-up; (3) Results: Of the 389 participants, 175 (45.0%) and 20 (5.1%) reported falls and fall-related fractures during the 12-month follow-up, respectively. Greater postural sway on foam, more depressive symptoms and lower physical activity levels at baseline were associated with falls during the 12-month follow-up. Slower walking speed at baseline was associated with fall-related fractures during the 12-month follow-up. These associations remained significant after adjusting for age, sex, body mass index, comorbidities and medication use; (4) Conclusions: This study suggests poor balance, low mood and a less active lifestyle are predictors of falls, and slower walking speed predicts fall-related fractures among community-dwelling older people with pain.

Training reactive balance using trips and slips in people with multiple sclerosis: A blinded randomised controlled trial.

BACKGROUND: This study examined the feasibility and efficacy of reactive balance training for improving stepping performance and reducing laboratory-induced falls in people with multiple sclerosis (MS). METHODS: Thirty people diagnosed with MS (18-70 years) participated in a blinded randomized controlled trial (ACTRN12618001436268). The intervention group (n = 14) underwent two 50-minute sessions (total 100 min) that exposed them to a total of 24 trips and 24 slips in mixed order, over one week. The control group (n = 16) received sham training (stepping over foam obstacles) with equivalent dosage. The primary outcome was falls into the harness (defined as >30% body weight) when exposed to trips and slips that were unpredictable in timing, location and type at post-assessment. Physical and psychological measures were also assessed at baseline and post assessments. RESULTS: The intervention and control groups completed 86% and 95% of the training protocols respectively. Incidence rate ratios (95% confidence intervals) of the intervention group relative to the control group were 0.57 (0.25, 1.26) for all falls, 0.80 (0.30, 2.11) for slip falls and 0.20 (0.04, 0.96) for trip falls in the laboratory. Kinematic analyses indicated the intervention participants improved dynamic stability, with higher centre of mass position and reduced trunk sway during recovery steps following a trip, compared to control. There were no significant differences between the intervention and control participants at post-assessment for other secondary outcome measures. CONCLUSIONS: Reactive balance training improved trip-induced dynamic stability, limb support, trunk control and reduced falls in people with MS. More research is required to optimise the training protocol and determine whether the beneficial effects of reactive balance training can be retained long term and generalize to fewer daily-life falls.

Correlations between reach, lean and ladder tipping risk.

Overreaching is a common cause of ladder falls, which occur frequently among older adults in the domestic setting. Reaching and body leaning during ladder use likely influence the climber-ladder combined center of mass and subsequently center of pressure (COP) position (location of the resultant force acting at the base of the ladder). The relationship between these variables has not been quantified, but is warranted to assess ladder tipping risk due to overreaching (i.e. COP traveling outside the ladder's base of support). This study investigated the relationships between participant maximum reach (hand position), trunk lean, and COP during ladder use to improve assessment of ladder tipping risk. Older adults (n = 104) were asked to perform a simulated roof gutter clearing task while standing on a straight ladder. Each participant reached laterally to clear tennis balls from a gutter. Maximum reach, trunk lean, and COP were captured during the clearing attempt. COPwas positively correlated withmaximum reach(p < 0.001; r = 0.74) and trunk lean (p < 0.001; r = 0.85). Maximum reach was positively correlated with trunk lean (p < 0.001; r = 0.89). The relationship between trunk lean and COP was stronger than that between maximum reach and COP, denoting the importance of body positioning on ladder tipping risk. For this experimental setup, regression estimates indicate reaching and lean distance of 113 cm and 29 cm from the ladder midline, respectively, would lead to ladder tipping on average. These findings assist with developing thresholds of unsafe reaching and leaning on a ladder, which can aid in reducing ladder falls.

The effects of optic flow on postural stability: Influence of age and fall risk.

BACKGROUND: Optic flow provides dynamic information relating to body position and motion with respect to visual frames of reference. This study investigated the effects of optic flow stimuli presented in four directions on postural stability in young and older adults. METHODS: Twenty-five young (20-40 years) and 51 older (≥65 years) people participated in this study, with the older group classified into low fall risk (n = 27), and high fall risk (n = 24) sub-groups. While standing in a dark room, participants viewed static scattered white dots for 30 s, followed by 30 s periods of optic flow consisting of white dots "moving" in one of four flow directions, randomised: radial expansion and contraction, circular anti-clockwise and clockwise. Centre of pressure (CoP) position, postural sway in anteroposterior (AP) and mediolateral (ML) axes, and muscle activity of tibialis anterior (TA), gastrocnemius medialis (GM) and tensor fascia latae (TFL) were recorded. RESULTS: Across groups, the four optic flow stimuli induced increased AP sway and three of the four optic flow stimuli induced increased ML sway, with concomitant increases in muscle activity, indicating optic flow stimuli induced a generalised destabilising, rather than a direction-specific, effect. Only one optic flow condition (radial contraction) induced a change in average CoP position, and this may reflect the adoption of a protective stance position to avoid a backward fall. Optic flow destabilised postural control more in older people compared with younger people, and radial expansion stimuli destabilised ML postural control more in the older high fall risk group compared with the older low fall risk group. CONCLUSION: Optic flow stimuli have a generalised destabilising effect on postural control across groups as shown by non-directional specific increases in postural sway and muscular activity. Optic flow stimuli have a greater impact on postural stability in older compared with younger adults and this is more pronounced in the ML plane for older people at increased risk of falls.

Risk factors for falls in community-dwelling older people with mild cognitive impairment: a prospective one-year study.

Objective: Mild cognitive impairment (MCI) is considered an intermediate stage between normal cognitive function and dementia. Fall risk is increased in this group, but there is limited literature exploring specific fall risk factors that may be addressed in fall prevention strategies. The aim of this study was to examine risk factors for falls in older people with MCI, focusing on cognitive, psychological and physical factors. Methods: Participants (n = 266, 45% women) were community-dwelling older people aged 70-90 years who met the criteria for MCI. Cognitive, psychological, sensorimotor and physical assessments, physical activity levels, medication use, general health and disability were ascertained at baseline. Falls were monitored prospectively for 12 months. Results: During follow-up, 106 (40%) participants reported one or more falls. Poorer visual contrast sensitivity, increased postural sway, lower levels of weekly walking activity, higher levels of depressive symptoms and psychotropic medication use were significantly associated with faller status (≥1 falls) in univariable analyses. Of these factors, poor visual contrast sensitivity, increased postural sway and psychotropic medication use were found to be significant independent predictors of falls in multivariable analysis while controlling for age and sex. No measures of cognitive function were associated with falls. Conclusions: Poor visual contrast sensitivity, impaired balance and psychotropic medication use predicted falls in community-dwelling people with MCI. These risk factors may be amenable to intervention, so these factors could be carefully considered in fall prevention programs for this population.

Situational factors that influence overreaching on a ladder during a gutter clearing task among older adults.

Ladder falls from overreaching are a problem in older adults. Evidence suggests ladder use behavior to be dependent on interfacing user and environmental circumstances (i.e. situational factors). This study investigates the effects of situational factors (remaining debris, ladder position, time into task, hand dominant reach, reaching disposition) on reaching during a gutter clearing task on a ladder in 104 older adults. Reaching was quantified as the maximum lateral center of pressure (COP) displacement from the ladder's center. A reach was classified as an overreach when the COP displaced outside the ladder width, indicative of a ladder tip. Reaching disposition, remaining debris, ladder position, and the interaction of reaching disposition and remaining debris predicted 20% of the reaching variability during the ladder task. Overreaching was observed in 40% of participants accounting for 13% of all extended reaches (beyond ladder). This work can guide interventions on mitigating overreaching and improving ladder safety.

Impact of pathological conditions on postural reflex latency and adaptability following unpredictable perturbations: A systematic review and meta-analysis.

BACKGROUND: Pathological conditions can impair responses to postural perturbations and increase risk of falls. RESEARCH QUESTION: To what extent are postural reflexes impaired in people with pathological conditions and can exercise interventions shorten postural reflexes? METHODS: MEDLINE, EMBASE, Scopus, SportDiscus and Web of Science were systematically searched for articles comparing muscle activation onset latency in people with pathological conditions to healthy controls following unpredictable perturbations including the effect of exercise interventions (registration: CRD42020170861). RESULTS: Fifty-three articles were included for systematic review. Significant delays in muscle activity onset following perturbations were evident in people with multiple sclerosis (n = 7, mean difference [MD]: 22 ms, 95% confidence interval [CI]: 11, 33), stroke (n = 10, MD: 34 ms, 95% CI: 19, 49), diabetes (n = 2, MD: 19 ms, 95% CI: 10, 27), HIV (n = 3, MD: 9 ms, 95% CI: 4, 14), incomplete spinal cord injury (n = 2, MD: 57 ms, 95% CI: 33, 80) and back and knee pain (n = 7, MD: 12 ms, 95% CI: 6, 18), but not in people with Parkinson's disease (n = 10) or cerebellar dysfunction (n = 4). Following exercise interventions, the paretic limb of stroke survivors (n = 3) displayed significantly faster muscle activation onset latency compared to pre-exercise (MD: -13 ms, 95% CI: -24, -4), with no significant changes in Parkinson's disease (n = 3). CONCLUSIONS: This systematic review demonstrated that postural reflexes are significantly delayed in people with multiple sclerosis (+22 ms), stroke (+34 ms), diabetes (+19 ms), HIV (+9 ms), incomplete spinal cord injury (+57 ms), back and knee pain (+12 ms); pathological conditions characterized by impaired sensation or neural function. In contrast, timing of postural reflexes was not impaired in people with Parkinson's disease and cerebellar dysfunction, confirming the limited involvement of supraspinal structures. The meta-analysis showed exercise interventions can significantly shorten postural reflex latencies in stroke survivors (-14 ms), but more research is needed to confirm this finding and in people with other pathological conditions.

Rapid Inhibition Accuracy and Leg Strength Are Required for Community-Dwelling Older People to Recover Balance From Induced Trips and Slips: An Experimental Prospective Study.

BACKGROUND AND PURPOSE: Falls can result in bone fractures and disability, presenting a serious threat to quality of life and independence in older adults. The majority of falls in community-living older adults occur while walking and are often caused by trips and slips. The study aimed to identify the specific sensorimotor and psychological factors required for older adults to recover balance from trips and slips. METHODS: Forty-one older adults aged 65 to 87 years were assessed on sensorimotor (knee extension strength, proprioception, postural sway, and edge contrast sensitivity), reaction (simple reaction time, stepping, and catching reaction inhibition), and psychological (general anxiety and concern about falling) measures. Using a harness system, participants walked at 90% of their usual pace on a 10-m walkway that could induce trips and slips in concealed and changeable locations. Post-perturbation responses resulting in more than 30% of body weight being recorded by the harness system were defined as falls. Poisson regressions were used to test associations between the sensorimotor, reaction, and psychological measures and number of falls. RESULTS: Fifty-one falls occurred in 25 of 41 participants. Poisson regression revealed body mass index, lower-limb proprioception, knee extension strength, rapid inhibition accuracy, concern about falling, and anxiety were significantly associated with the rate of falls. Other measures including postural sway were not statistically significant. Using stepwise Poisson regression analyses, normalized knee extension strength (rate ratio [RR]: 0.68, 95% confidence interval [CI]: 0.47-0.98), and rapid inhibition accuracy (RR: 0.64, 95% CI: 0.46-0.87) were independently associated with falls. CONCLUSION: Our findings suggest rapid inhibition accuracy and adequate leg strength are required for older adults to recover balance from trips and slips. The mechanisms for balance recovery during daily life activities are likely different from those for static balance, suggesting the need for task-specific assessments and interventions for fall prevention in older adults.

Reactive balance responses to a trip and slip during gait in people with multiple sclerosis.

BACKGROUND: To examine reactive balance responses to a trip and slip during gait in people with multiple sclerosis (MS). METHODS: This cross-sectional laboratory study involved 29 participants with MS (50.6 ± 13.4 years) and 29 gender-and-aged-matched healthy controls (50.9 ± 19.2 years). Falls following an induced trip and slip along a 10 m walkway, approach (e.g. gait speed, step length, foot contact angle) and recovery strategies (e.g. response time, extrapolated centre of mass position, margin of stability) were compared between the two groups. FINDINGS: The rate of falls was significantly higher in the participants with MS relative to healthy controls (rate ratio=2.82, 95% confidence interval [CI]=1.42, 5.61). Participants with MS also experienced more trip falls (odds ratio [OR]=3.90, 95% CI=1.16, 13.08) and more slip falls (OR=6.27, 95% CI=1.95, 20.22) than the heathy controls. Participants with MS had significantly slower gait speed, step length, cadence, and foot contact angle during approach (P < 0.05). Following slips, participants with MS had significantly greater stance limb knee flexion (P < 0.05), suggesting inadequate lower limb support to recover balance post-slip. Following trips, participants with MS had significantly delayed response initiation, lower toe clearance, shorter step length, and greater trunk sway (P < 0.05). Fewer participants with MS showed a hopping response to clear the obstacle (P < 0.05). INTERPRETATION: Multiple sclerosis impairs reactive balance responses to a trip and slip associated with reduced lower limb function and delayed postural responses. Neurorehabilitation targeting reactive balance may facilitate fall prevention in people with multiple sclerosis.

Ladder Use in Older People: Type, Frequency, Tasks and Predictors of Risk Behaviours.

Ladder fall and injury risk increases with age. People who present to a hospital after an injurious ladder fall have been surveyed, but little is known about ladder use in the community. The purpose of this study was to: (1) document salient factors related to ladder safety, and (2) determine physical, executive function, psychological and frequency-of-use factors associated with unsafe ladder use in older people. One hundred and two older people (aged 65+ years) were recruited. Participants completed questionnaires on demographics, health, and ladder use (type, frequency, task, behaviours) and underwent assessments of physical and executive function ability. Results showed both older men and women commonly use step ladders (61% monthly, 96% yearly), mostly inside the home for tasks such as changing a lightbulb (70%) and decorating (43%). Older men also commonly use straight ladders (27% monthly, 75% yearly), mostly outside the home for tasks such as clearing gutters (74%) and pruning trees (40%). Unsafe ladder use was more common in males and individuals with greater ladder use frequency, greater quadriceps strength, better upper limb dexterity, better balance, better stepping ability, greater self-reported everyday risk-taking, a lower fear of falling, and fewer health problems compared to their counterparts (all p < 0.05). These findings document ladder use by older people and provide insight into unsafe ladder behaviours that may be amenable to interventions to reduce ladder falls and associated injuries.