Choice Stepping Reaction Time Research Articles

Perturbation-based balance training of older adults and effects on physiological, cognitive and sociopsychological factors: a secondary analysis from a randomised controlled trial with 12-month follow-up

BackgroundPerturbation-based balance training (PBT) has shown promising, although diverging, fall-preventive effects; however, the effects on important physical, cognitive and sociopsychological factors are currently unknown. The study aimed to evaluate these...

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.

Dance Exergames for Older Adults: A Systematic Review and Meta-Analysis With Narrative Synthesis.

A systematic review and meta-analysis with narrative synthesis was conducted to evaluate the impact of dance exergaming on older adults' health-related outcomes and its feasibility, usability, and safety. PubMed, Scopus, CINAHL, Web of Science, The Cochrane Library, ProQuest Dissertations and Theses Global, and Google Scholar were searched from inception to December 7, 2023. Interventional studies using immersive or nonimmersive virtual reality platforms conducted on older adults ≥60 years old were eligible. Meta-analysis was conducted using the random effects model by pooling mean differences (MD) or standardized mean differences. Outcomes were narratively synthesized when meta-analysis was not possible. Forty-three articles from 37 studies were included (n = 1139 participants at baseline). Postintervention, dynamic balance measured using Berg Balance Scale (pooled MD = 2.65, 95% CI: 1.73-3.57, p < .0001), Timed-Up-and-Go times (pooled MD = -1.04, 95% CI: -2.06 to -0.03, p = .04), choice stepping reaction time (pooled MD = -92.48, 95% CI: -167.30 to -17.67, p = .02), and movement time (pooled MD = -50.33, 95% CI: -83.34 to -17.33, p = .003) were significantly better in the experimental group compared to the control group. Adherence ranged from 76.5% to 100%, whereas attrition ranged from 9.1% to 31.9%. Most participants completed the intervention with no or minimal adverse effects. Dance exergames are effective, feasible, usable, and safe for older adults. Further research is needed as the findings were limited by small sample sizes. Many studies could not be included in the meta-analysis as outcomes were too varied.

Prefrontal and Motor Planning Cortical Activity during Stepping Tasks Is Related to Task Complexity but Not Concern about Falling in Older People: A fNIRS Study.

This study investigated the effect of concern about falling on neural efficiency during stepping in older people. Community-dwellers aged >65 years were categorised as having low (n = 71) and high (n = 28) concerns about falling based on the Iconographical Falls Efficacy Scale (IconFES 10-item, scores <19 and ≥19, respectively). Participants performed a choice stepping reaction time test (CSRT), an inhibitory CSRT (iCSRT), and a Stroop stepping test (SST)) on a computerised step mat. Cortical activity was recorded using functional near-infrared spectroscopy. There were no significant differences in stepping response times or cortical activity in the dorsolateral prefrontal cortex (DLPFC), supplementary motor area (SMA), and premotor cortex (PMC) between those with and without concern about falling. However, stepping response times and cortical activity in the PFC, SMA, and PMC were significantly higher in the SST compared with the CSRT in the whole sample. PMC activity was also higher in the SST compared to the iCSRT. These findings demonstrate that cortical activity is higher in cognitively demanding stepping tasks that require selective attention and inhibition in healthy older people. The lack of association between concern about falling and neural efficiency during stepping in this older sample may reflect their only moderate scores on the IconFES.

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.

Evaluation of a Novel Step Training Mobile App Intervention in Cardiopulmonary Rehabilitation: A Single-Arm Prospective Cohort Study

Objective: To establish the usability, acceptability, safety, and exercise adherence of a step training mobile app. Design: A single-arm prospective cohort study. Setting: Royal Brisbane and Women's Hospital, Australia. Subjects: Twenty-six cardiopulmonary rehabilitation participants. Intervention: Twelve weeks of step training using the mobile app Clock Yourself. Participants used Clock Yourself at home and during cardiopulmonary rehabilitation sessions, prescribed for a total of 15-20 minutes three times a week. Main Measures: The primary outcomes of interest were usability and acceptability and were measured using the System Usability Scale (SUS) and Attitudes to Falls-Related Interventions Scale (AFRIS) questionnaire, respectively. Safety and adherence were measured by self-report and participant diary, respectively. Secondary outcomes measuring changes in stepping, gait, balance, and physical performance included Manual test of Choice Stepping Reaction Time (CSRT-M), Short Physical Performance Battery (SPPB), Gait speed with and without a cognitive dual task (DT) and Timed Up and Go with and without a cognitive DT (TUG and TUGcog). Results: Twenty-one participants completed the study. Clock Yourself was considered highly useable (SUS [median] = 82.5/100; interquartile range [IQR, 67.5-95], equating to an "A" rating [A-F scale]) and acceptable (AFRIS [median] = 38/42 [IQR, 31-41]). Participants practiced Clock Yourself for a median of 18.29 minutes per week and no adverse events were reported. At 12 weeks, mean change in CSRT-M, SPPB, gait speed, DT gait speed, TUG, and TUGcog were all statistically significant (P < 0.01). Conclusion: Twelve weeks of mobile app-based step training was safe and considered usable and acceptable by participants. On average, participants did not meet the prescribed practice dosage. Statistically significant changes were observed in all physical measures; however, results are confounded by participation in cardiopulmonary rehabilitation and lack of control group.

Feasibility and Safety of Whole-Body Electromyostimulation in Frail Older People-A Pilot Trial.

Whole-body electromyostimulation (WB-EMS) induces high-intense stimuli to skeletal muscles with low strain on joints and the autonomic nervous system and may thus be suitable for frail, older people. However, if trained at very high intensities, WB-EMS may damage muscles and kidneys (rhabdomyolysis). This study aimed at investigating the feasibility, safety and preliminary efficacy of WB-EMS in frail, older people. Seven frail (81.3 ± 3.5 years), 11 robust (79.5 ± 3.6 years), 10 young (29.1 ± 6.4 years) participants completed an eight-week WB-EMS training (week 1–4: 1x/week; week 5–8: 1.5x/week) consisting of functional exercises addressing lower extremity strength and balance. Feasibility was assessed using recruitment, adherence, retention, and dropout rates. The satisfaction with WB-EMS was measured using the Physical Activity Enjoyment Scale for older adults (PACES-8). In week 1, 3, and 8 creatine kinase (CK) was assessed immediately before, 48 and 72 h after WB-EMS. Symptoms of rhabdomyolysis (muscle pain, muscle weakness, myoglobinuria) and adverse events were recorded. Functional capacity was assessed at baseline and after 8 weeks using the Short Physical Performance Battery (SPPB), Timed Up-and-Go Test (TUG), Choice Stepping Reaction Time Test (CSRT), 30-second Chair-Stand Test (30-STS), maximum isometric leg strength and handgrip strength. The recruitment rate of frail individuals was 46.2%, adherence 88.3% and the dropout rate 16.7%. All groups indicated a high satisfaction with WB-EMS. CK activity was more pronounced in young individuals with significant changes over time. Within older people CK increased borderline-significantly in the frail group from baseline to week 1 but not afterwards. In robust individuals CK increased significantly from baseline to week 1 and 3. No participant reached CK elevations close to the threshold of ≥5,000 U/l and no symptoms of rhabdomyolysis were observed. With the exception of the TUG (p = 0.173), frail individuals improved in all tests of functional capacity. Compared to the young and robust groups, frail individuals showed the greater improvements in the SPPB, handgrip strength, maximum isokinetic hip-/knee extension and flexion strength. WB-EMS is feasible for frail older people. There were no clinical signs of exertional rhabdomyolysis. WB-EMS proved to be sufficiently intense to induce meaningful changes in functional capacity with frail individuals showing greater improvements for several measures.

Effects of exergaming on cognition, lower limb functional coordination, and stepping time in people with multiple sclerosis: a randomized controlled trial

Purpose To compare the effects of exergaming versus conventional exercises on cognition, lower-limb functional coordination, and stepping time in people with multiple sclerosis (PwMS). Methods Thirty-six PwMS were randomly assigned to either intervention (n = 18) or control (n = 18) group and received 18 training sessions during six weeks. The intervention group performed exergames that required multidirectional timed-stepping, weight-shifting, and walking while the control group performed conventional matched exercises. Trail making test (TMT part A, B; TMT-A, TMT-B, TMT B-A), six-spot step test (SSST), and choice stepping reaction time (CSRT-including reaction time (RT), movement time (MVT), and total response time (TRT)) were assessed pre- and post-intervention (short-term), and after three-month follow-up (mid-term). Results The intervention group showed faster TMT-B (p = 0.003) and TMT B-A (p = 0.002) at post-intervention and faster SSST at both post-intervention (p = 0.002) and follow-up (p = 0.04). The CSRT components showed no between-group differences at post-intervention; however, at follow-up, the intervention group had lower TRT (p = 0.046) and MVT (p = 0.015). TMT-A and RT had no significant between-group differences. Conclusions In short-term, exergames led to more improvements in complex attention, executive function, and lower-limb functional coordination comparing to the matched conventional exercises. In mid-term, exergaming was more effective for improving stepping time and lower-limb functional coordination. However, the two approaches did not show any superiority over each other for improving simple attention and RT. Implications for rehabilitation When designed properly, exergames have great potential to improve attention and executive function of people with multiple sclerosis (PwMS), at least in the short-term. Exergames seem like an appropriate option for improving lower limb coordination and decreasing choice stepping response time among PwMS in the mid-term. Exergames do not have superiority in improving the choice stepping reaction time compared to their matched conventional treatment.

Choice Stepping Reaction Time under Unstable Conditions in Healthy Young and Older Adults: A Reliability and Comparison Study

Choice Stepping Reaction Time under Unstable Conditions in Healthy Young and Older Adults: A Reliability and Comparison Study

Evidence of slow and variable choice-stepping reaction time in cancer survivors with chemotherapy-induced peripheral neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) is reported to affect up to 70 % of cancer survivors. Despite evidence that CIPN-related impairments often translate into balance and mobility deficits, the effects on stepping and quality of gait, well-documented risk factors for falls, are unclear. (i) Establish choice-stepping reaction time (CSRT) performance in survivors with CIPN compared to young and older healthy controls and people with Parkinson's disease; (ii) document walking stability; (iii) investigate relationships between stepping and gait data to objective and patient-reported outcomes. 41 cancer survivors with CIPN (mean (SD) age: 60.8 (9.7) years) who were ≥3months post chemotherapy, performed tests of simple and inhibitory CSRT. Walking stability measures were derived from 3-D accelerometry data during the 6-minute walk test. CIPN was assessed using neurological grading and patient-reported outcome measures (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire in CIPN Questionnaire scale EORTC CIPN20). In both stepping tests, CIPN participants performed at the level of adults aged 10 years older and people with mild to moderate Parkinson's disease. Mean (SD) total stepping response times in both CSRT (1160 (190) milliseconds) and inhibitory CSRT (1191 (164) milliseconds) tests were not associated with objective neurological grading but were correlated with increased difficulty feeling the ground. Participants with lower-limb vibration sensation deficit had slower and more variable CSRT times. There were no associations between walking stability and objective measures of CIPN, and limited correlations with the EORTC-CIPN20. Cancer survivors with CIPN showed deficits in voluntary stepping responses and seemed to compensate for their sensory and motor deficits by walking slower to maintain stability. Objective and patient-reported outcomes of CIPN were correlated with slower and more variable stepping response times. Future studies should aim to identify the causes of the apparent premature decline in cognitive-motor function and develop remediating interventions.

Cognitive and Motor Cortical Activity During Cognitively Demanding Stepping Tasks in Older People at Low and High Risk of Falling.

Background: Choice stepping reaction time tasks are underpinned by neuropsychological, sensorimotor, and balance systems and therefore offer good indices of fall risk and physical and cognitive frailty. However, little is known of the neural mechanisms for impaired stepping and associated fall risk in older people. We investigated cognitive and motor cortical activity during cognitively demanding stepping reaction time tasks using functional near-infrared spectroscopy (fNIRS) in older people at low and high fall risk.Methods: Ninety-five older adults [mean (SD) 71.4 (4.9) years, 23 men] were categorized as low or high fall risk [based on 12-month fall history (≥2 falls) and/or Physiological Profile Assessment fall risk score ≥1]. Participants performed a choice stepping reaction time test and a more cognitively demanding Stroop stepping task on a computerized step mat. Cortical activity in cognitive [dorsolateral prefrontal cortex (DLPFC)] and motor (supplementary motor area and premotor cortex) regions was recorded using fNIRS. Stepping performance and cortical activity were contrasted between the groups and between the choice and Stroop stepping conditions.Results: Compared with the low fall risk group (n = 71), the high fall risk group (n = 24) exhibited significantly greater DLPFC activity and increased intra-individual variability in stepping response time during the Stroop stepping task. The high fall risk group DLPFC activity was greater during the performance of Stroop stepping task in comparison with choice stepping reaction time. Regardless of group, the Stroop stepping task elicited increased cortical activity in the supplementary motor area and premotor cortex together with increased mean and intra-individual variability of stepping response times.Conclusions: Older people at high fall risk exhibited increased DLPFC activity and stepping response time variability when completing a cognitively demanding stepping test compared with those at low fall risk and to a simpler choice-stepping reaction time test. This increased hemodynamic response might comprise a compensatory process for postural control deficits and/or reflect a degree of DLPFC neural inefficiency in people with increased fall risk.

Neurocognitive measures predict voluntary stepping performance in older adults post-hip fracture

BackgroundHip fracture is a debilitating injury, especially in older adults. The purpose of this study was to determine the relationships between Trail-Making test performance and parameters of the choice stepping reaction time test in community-dwelling older adults after hip fracture. MethodsTwenty-four older adults post-hip fracture repair participated in an ancillary study for physical therapy interventions. Measures included Trail-Making test (Parts A & B) scores, movement time (time from foot liftoff to touchdown), step speed, reaction time (time from cue to foot liftoff), and total response time (time from step cue to touchdown) in the forward and lateral directions. Paired t-tests and multiple linear regressions were used for analysis. FindingsSignificant differences were found in movement time, speed and reaction time between limbs in the lateral direction, and in movement and reaction time in the forward direction. Trails A predicted step speed, reaction time and total response time for the fractured limb in the lateral direction, as well as reaction time and total response time in the forward direction. However, Trails A could not predict performance for the non-fractured limb. Trails B predicted stepping performance for both limbs in the forward and lateral directions. InterpretationTrails A correlated with the fractured limb's ability to perform the choice stepping test, but not in the non-fractured limb. Meanwhile, Trails B correlated with stepping performance in both limbs, suggesting those with poorer executive function have a lower protective stepping capability and may be at a higher risk for future falls and injury.

People With Parkinson’s Disease Exhibit Reduced Cognitive and Motor Cortical Activity When Undertaking Complex Stepping Tasks Requiring Inhibitory Control

Background People with Parkinson’s disease (PD) have difficulties generating quick and accurate steps in anticipation of and/or in response to environmental hazards. However, neural mechanisms underlying performance in cognitively demanding stepping tasks are unclear. Objective This study compared activation patterns in cognitive and motor cortical regions using functional near-infrared spectroscopy (fNIRS) between people with PD and age-matched healthy older adults (HOA) during stepping tasks. Methods Fifty-two people with PD and 95 HOA performed a simple choice stepping reaction time test (CSRT) and 2 cognitively demanding stepping tests (inhibitory CSRT [iCSRT] and Stroop stepping test [SST]) on a computerized step mat. Cortical activation in the dorsolateral prefrontal cortex (DLPFC), Broca’s area, supplementary motor area (SMA), and premotor cortex (PMC) were recorded using fNIRS. Stepping performance and cortical activity were contrasted between groups and between the CSRT and the iCSRT and SST. Results The PD group performed worse than the HOA in all 3 stepping tests. A consistent pattern of interactions indicated differential hemodynamic responses between the groups. Compared with the CSRT, the PD group exhibited reduced DLPFC activity in the iCSRT and reduced SMA and PMC activity in the SST. The HOA exhibited increased DLPFC, SMA, and PMC activity when performing the SST in comparison with the CSRT task. Conclusions In contrast to the HOA, the PD group demonstrated reduced cortical activity in the DLPFC, SMA, and PMC during the more complex stepping tasks requiring inhibitory control. This may reflect subcortical and/or multiple pathway damage with subsequent deficient use of cognitive and motor resources.

The role of concern about falling on stepping performance during complex activities

BackgroundThere is limited understanding of the underlying mechanisms explaining the role of concern about falling on fall risk in older people. Anxiety is known to interact with cognitive resources and, as people get older, they require more cognitive resources to maintain balance. This might affect an individual’s ability to perform cognitive-motor tasks concurrently. The aim of this study was to investigate the effect of a visuospatial dual-task on stepping performance in older people with and without concern about falling and the impact of repeating this task in those with high concern about falling.MethodsThree-hundred-eight community-dwelling older people, aged 70 to 90 years old, participated in the study. Participants were asked to perform a Choice Stepping Reaction Time (CSRT) task in two conditions; once without any other tasks (single task condition), and once while simultaneously performing a visuospatial task (dual-task condition). Participants were asked to rate their levels of concern and confidence specifically related to each of the 25 stepping trials (before/after). We also measured general concern about falling, affect, and sensorimotor and cognitive functioning.ResultsTotal stepping reaction times increased when participants also performed the visuospatial task. The relation between general concern about falling and stepping reaction time, was affected by sensorimotor and executive functioning. Generalised linear mixed models showed that the group with moderate to high levels of general concern about falling had slower total stepping reaction times than those with lower levels of concern about falling, especially during the dual-task condition. Individuals with greater general concern about falling showed reduced confidence levels about whether they could do the stepping tasks under both conditions. Repeatedly performing the stepping task reduced the immediate task-specific concern about falling levels and increased confidence in all participants.ConclusionsThese findings reveal that people with higher general concern about falling experienced more difficulties during a dual-task condition than people with lower levels of concern. Of further interest, better sensorimotor and cognitive functioning reduced this effect. Graded exposure has potential to reduce concern about falling during fear-evoking activities, especially in conjunction with therapies that improve balance, mood and cognitive function.

Comparison of processing speed, balance, mobility and fear of falling between hypertensive and normotensive individuals

BackgroundHypertension (HT) contributes substantially to poor physical function, cognitive dysfunction, cardiovascular problems and to all-cause mortality. Performance in activities requiring attention, speed and coordination might also be affected in individuals with HT. ObjectiveThis study compared the processing speed, static and dynamic balance, functional mobility and fear of falling between individuals with hypertension (HT group) and normotensive individuals (NT group). MethodsOne-hundred and twenty-eight individuals were included: NT group (n = 64) and HT group (n = 64). The Choice Stepping Reaction Time Test was used for the evaluation of processing speed, Single Leg Stance test for static balance evaluation, “Y” Balance Test for dynamic balance evaluation, Timed Up and Go test with single and dual tasking for the evaluation of functional mobility and Falls Efficacy Scale for assessing fear of falling. ResultsThe processing speed of the HT group was slower than that of the NT group; the total response time (RsT) in Stepping Reaction Test (SRT) (mean difference [MD] = −0.2, 95% CI = −0.3, 0), and Stroop Test (ST) [ST-A (MD = −0.4, 95% CI = −0.5, −0.2), ST-B (MD = −0.5, 95% CI = −0.7, −0.2) and ST-C (MD = −0.6, 95% CI = −0.8, −0.3). Additionally, the static [single leg stance, eyes open, right side (MD = 12.7, 95% CI = 6.3, 19.0) and left side (MD = 13.6, 95% CI = 7.2, 19.9)] and dynamic balance [Y balance test, composite score, right lower extremity (MD = 8.5, 95% CI = 4.4, 12.5) and left lower extremity (MD = 5.2, 95% CI = 1.5, 8.8) scores of the HT group were lower than those of the NT group. The HT group required a longer time to complete the functional mobility test measured with Timed Up And Go Test during both single task (MD = −0.8, 95% CI = −1.1, −0.4), cognitive dual task (MD = −1.5, 95% CI = −2.4, −0.5) and manual dual task (MD = −0.9, 95% CI = −1.3, −0.4) in comparison to the NT group. Also, the HT group had higher levels of fear of falling (MD = −7.6, 95% CI = −10.9, −4.2). ConclusionHypertensive individuals present slower processing speed, reduced static and dynamic balance, decreased functional mobility and higher fear of falling in comparison to normotensive individuals.

Executive Functioning, Muscle Power and Reactive Balance Are Major Contributors to Gait Adaptability in People With Parkinson's Disease.

Background and Aim: The ability to adapt gait when negotiating unexpected hazards is crucial to maintain stability and avoid falling. This study investigated cognitive, physical and psychological factors associated with gait adaptability required for obstacle and stepping target negotiation in people with Parkinson’s disease (PD).Methods: Fifty-four people with PD were instructed to either: (a) avoid an obstacle at usual step distance; or (b) step onto a target at either a short or long step distance projected on a walkway two heel strikes ahead and then continue walking. Participants also completed clinical [Hoehn & Yahr rating scale; Movement Disorders Society version of the Unified Parkinson’s Disease Rating Scale motor section (MDS-UPDRS-III)], cognitive [simple reaction time, Trail Making and Stroop stepping (difference between incongruent and standard Choice Stepping Reaction Time, CSRT) tests], physical [hip abductor muscle power and reactive balance (pull test from the MDS-UPDRS-III)] and psychological (Fall Efficacy Scale–International) assessments.Results: Discriminant function analysis revealed Stroop stepping test (inhibitory control) performance was the best predictor of stepping errors across the Gait Adaptability Test (GAT) conditions. Poorer executive function [Trail Making Test (TMT)] and reactive balance predicted poorer stepping accuracy in the short target condition; poorer reactive balance predicted increased number of steps taken to approach the obstacle and the long target; and poorer executive function predicted obstacle avoidance. Weaker hip abductor muscle power, poorer reactive balance, slower reaction time, poorer executive function and higher concern about falling were significant predictors of shorter step length while negotiating the obstacle/targets.Conclusion: Superior executive function, effective reactive balance and good muscle power were associated with successful gait adaptability. Executive function and reactive balance appear particularly important for precise foot placements; and cognitive capacity for step length adjustments for avoiding obstacles. These findings suggest that impaired inhibitory control contributes to stepping errors and may increase fall risk in people with PD. These findings help elucidate mechanisms for why people with PD fall and may facilitate fall risk assessments and fall prevention strategies for this group.

Mental Flexibility Influences the Association Between Poor Balance and Falls in Older People - A Secondary Analysis.

Impairments of balance predispose older people to falls. Some cognitive functions, especially executive functioning have been shown to affect balance and discriminate fallers from non-fallers. Mental flexibility is a component of the executive function and comprises multiple cognitive processes that work together to adjust the course of thoughts or actions according to the changing demands of a situation without the use of explicit instructions. However, the role of mental flexibility in balance in older people remains unclear. The study aim was to examine the relationship between mental flexibility and falls in a cohort of 212 older people (80.6 ± 4.9 years; 62% female). We hypothesized that: (i) participants with impaired balance would have worse mental flexibility compared to those with good balance; and (ii) poor mental flexibility would predict falls in the sub-group with impaired balance. Balance performance was assessed by measuring postural sway while standing on a medium density foam mat with eyes open for 30 s. Mental flexibility was assessed using a computerized short-form of the Wisconsin Card Sorting Test (WCST; 64 cards) with its sub-components comprising general performance, perseveration, failure-to-maintain set and conceptual ability. Falls were measured prospectively for 12-months using monthly calendars. MANCOVA revealed that WCST performance was associated with balance [Wilks’ Lambda = 0.883, F = 2.168; p = 0.013, partial eta squared () = 0.061] due primarily to reduced concept formation ability [F(2,207) = 5.787, p = 0.004, = 0.053]. Negative binomial regression analysis adjusting for age, education, contrast sensitivity, proprioception, inhibition, and inhibitory choice stepping reaction time (iCSRT) revealed that lower concept formation ability was predictive for falls [Incidence Rate Ratio 1.048 (95% confidence interval 1.016–1.081)]. Further, lower concept formation ability partly explained the association between balance and falls: i.e., fallers in the upper balance tertile had reduced concept formation performance whereas non-fallers had similar concept formation performance across the three balance tertiles. These findings suggest that poor mental flexibility affects the ability to maintain steady balance contributing to increased risk of falls in older people.

Postural adjustments in anticipation of predictable perturbations allow elderly fallers to achieve a balance recovery performance equivalent to elderly non-fallers

BackgroundIn numerous laboratory-based perturbation experiments, differences in the balance recovery performance of elderly fallers and non-fallers are moderate or absent. This performance may be affected by the subjects adjusting their initial posture in anticipation of the perturbation.Research questions: Do elderly fallers and non-fallers adjust their posture in anticipation of externally-imposed perturbations in a laboratory setting? How does this impact their balance recovery performance? Methods21 elderly non-fallers, 18 age-matched elderly fallers and 11 young adults performed both a forward waist-pull perturbation task and a Choice Stepping Reaction Time (CSRT) task. Whole-body kinematics and ground reaction forces were recorded. For each group, we evaluated the balance recovery performance in the perturbation task, change in initial center of mass (CoM) position between the CSRT and the perturbation task, and the influence of initial CoM position on task performance. ResultsThe balance recovery performance of elderly fallers was equivalent to elderly non-fallers (p > 0.5 Kolmogorov-Smirnov test). All subject groups anticipated forward perturbations by shifting their CoM backward compared to the CSRT task (young: 2.1% of lower limb length, elderly non-fallers: 2.7%, elderly fallers: 2.2%, Hodges-Lehmann estimator, p < 0.001 Mann-Whitney U). This backward shift increases the probability of resisting the traction without taking a step. SignificanceThe ability to anticipate perturbations is preserved in elderly fallers and may explain their preserved balance recovery performance in laboratory-based perturbation tasks. Therefore, future fall risk prediction studies should carefully control for this postural strategy, by interleaving perturbations of different directions for example.

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

BackgroundDecline in the ability to take effective steps and to adapt gait, particularly under challenging conditions, may be important reasons why people with Parkinson's disease (PD) have an increased risk of falling. This study aimed to determine the extent of stepping and gait adaptability impairments in PD individuals as well as their associations with PD symptoms, cognitive function and previous falls. MethodsThirty-three older people with PD and 33 controls were assessed in choice stepping reaction time, Stroop stepping and gait adaptability tests; measurements identified as fall risk factors in older adults. ResultsPeople with PD had similar mean choice stepping reaction times to healthy controls, but had significantly greater intra-individual variability. In the Stroop stepping test, the PD participants were more likely to make an error (48 vs 18%), took 715 ms longer to react (2312 vs 1517 ms) and had significantly greater response variability (536 vs 329 ms) than the healthy controls. People with PD also had more difficulties adapting their gait in response to targets (poorer stepping accuracy) and obstacles (increased number of steps) appearing at short notice on a walkway. Within the PD group, higher disease severity, reduced cognition and previous falls were associated with poorer stepping and gait adaptability performances. ConclusionsPeople 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.

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

Objectives: 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. Design: A single-blinded randomised controlled trial. Setting: Community (experimental intervention), university laboratory (outcome measures). Subjects: Sixty community-dwelling people with Parkinson’s disease. Interventions: Home-based step training using videogame technology. Main measures: The primary outcomes were the choice stepping reaction time test and Functional Gait Assessment. Secondary outcomes included physical and neuropsychological measures associated with falls in Parkinson’s disease, number of falls over six months and self-reported mobility and balance. Results: Post intervention, there were no differences between the intervention (n = 28) and control (n = 25) groups in the primary or secondary outcomes except for the Timed Up and Go test, where there was a significant difference in favour of the control group (P = 0.02). Intervention participants reported mobility improvement, whereas control participants reported mobility deterioration—between-group difference on an 11-point scale = 0.9 (95% confidence interval: −1.8 to −0.1, P = 0.03). Interaction effects between intervention and disease severity on physical function measures were observed (P = 0.01 to P = 0.08) with seemingly positive effects for the low-severity group and potentially negative effects for the high-severity group. Conclusion: 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.