Development and Process Evaluation of a 5-Week Exercise Program to Prevent Falls in People after Stroke: The FALLS Program

Characteristics of unsuccessful reactive responses to lateral loss of balance in people with stroke

PURPOSE

The effectiveness of reactive responses to a sudden loss of balance is a critical factor that determines whether a fall will occur. We examined the strategies and kinematics associated with successful and unsuccessful balance recovery following lateral loss of balance in people with stroke (PwS).

METHODS

Eleven PwS were included in the analysis. They were exposed to unannounced right and left horizontal surface translations and demonstrated both successful and unsuccessful balance responses at the same perturbation magnitude. Reactive step strategies and kinematics were investigated comparatively in successful and unsuccessful recovery tests.

RESULTS

The crossover strategy was used in most of the unsuccessful tests (7/11) while the unloaded-leg side-step in the successful tests (6/11). There were no significant differences in the reactive step initiation time in unsuccessful vs. successful tests. However, the step execution time, step length and center of mass displacement were significantly higher during the first recovery step in unsuccessful tests.

CONCLUSIONS

PwS have difficulties in controlling and decelerating the moving center of mass following a lateral loss of balance. The increased step time and step length of the first reactive step in unsuccessful vs. successful tests suggest the crossover step strategy may be ineffective for PwS.

Walking-adaptability therapy after stroke: results of a randomized controlled trial

BACKGROUND

The ability to adapt walking to environmental properties and hazards, a prerequisite for safe ambulation, is often impaired in persons after stroke.

RESEARCH QUESTION

The aim of this study was to compare the efficacy of two walking-adaptability interventions: a novel treadmill-based C-Mill therapy (using gait-dependent augmented reality) and the standard overground FALLS program (using physical context). We expected sustained improvements for both treatment groups combined but hypothesized better outcomes for C-Mill therapy than the FALLS program due to its expected greater amount of walking practice.

METHODS

In this pre-registered single-centre parallel group randomized controlled trial, forty persons after stroke (≥ 3 months ago) with walking and/or balance deficits were randomly allocated to either 5 weeks of C-Mill therapy or the FALLS program. The primary outcome measure was the standard walking speed as determined with the 10-meter walking test (10MWT). Additionally, context-specific walking speed was assessed in environments enriched with either stationary physical context (10MWT context) or suddenly appearing visual images (Interactive Walkway obstacles). The walking-adaptability scores of those enriched walking tests served as secondary outcome measures. Furthermore, a cognitive task was added to all three assessments to evaluate dual-task performance in this context. Finally, the participants' experience and amount of walking practice were scored. The outcome measures were assessed at four test moments: pre-intervention (T0), post-intervention (T1), 5-week post-intervention retention (T2), and 1-year post-intervention follow-up (T3).

RESULTS

No significant group differences were found between the interventions for the primary outcome measure standard walking speed, but we found a greater improvement in context-specific walking speed with stationary physical context of the C-Mill therapy compared to the FALLS program at the post-intervention test, which was no longer significant at retention. Both interventions were well received, but C-Mill therapy scored better on perceived increased fitness than the FALLS program. C-Mill therapy resulted in twice as many steps per session of equal duration than the FALLS program. The "change-over-time" analyses for participants of both interventions combined showed no significant improvements in the standard walking speed; however, significant improvements were found for context-specific walking speed, walking adaptability, and cognitive dual-task performance.

SIGNIFICANCE

This study showed no between-group differences between the novel treadmill-based C-Mill therapy and the standard overground FALLS program with respect to the primary outcome measure standard walking speed. However, the greater amount of walking practice observed for the C-Mill group, an essential aspect of effective intervention programs after stroke, may underlie the reported increased perceived fitness and observed increased context-specific walking speed for the C-Mill group directly after the intervention. Although the "change-over-time" results for all participants combined showed no improvement in the standard walking speed, context-specific walking speed and walking adaptability showed sustained improvements after the interventions, underscoring the importance of including walking-adaptability training and assessment in rehabilitation post stroke.

TRIAL REGISTRATION

The Netherlands Trial Register NTR4030 . Registered 11 June 2013.

Does perturbation-based balance training prevent falls among individuals with chronic stroke? A randomised controlled trial

OBJECTIVES

No intervention has been shown to prevent falls poststroke. We aimed to determine if perturbation-based balance training (PBT) can reduce falls in daily life among individuals with chronic stroke.

DESIGN

Assessor-blinded randomised controlled trial.

SETTING

Two academic hospitals in an urban area.

INTERVENTIONS

Participants were allocated using stratified blocked randomisation to either 'traditional' balance training (control) or PBT. PBT focused on improving responses to instability, whereas traditional balance training focused on maintaining stability during functional tasks. Training sessions were 1 hour twice/week for 6 weeks. Participants were also invited to complete 2 'booster' training sessions during the follow-up.

PARTICIPANTS

Eighty-eight participants with chronic stroke (>6 months poststroke) were recruited and randomly allocated one of the two interventions. Five participants withdrew; 42 (control) and 41 (PBT group) were included in the analysis.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was rate of falls in the 12 months post-training. Negative binomial regression was used to compare fall rates between groups. Secondary outcomes were measures of balance, mobility, balance confidence, physical activity and social integration.

RESULTS

PBT participants reported 53 falls (1.45 falls/person-year) and control participants reported 64 falls (1.72 falls/person-year; rate ratio: 0.85(0.42 to 1.69); p=0.63). Per-protocol analysis included 32 PBT and 34 control participants who completed at least 10/12 initial training sessions and 1 booster session. Within this subset, PBT participants reported 32 falls (1.07 falls/person-year) and control participants reported 57 falls (1.75 falls/person-year; rate ratio: 0.62(0.29 to 1.30); p=0.20). PBT participants had greater improvement in reactive balance control than the control group, and these improvements were sustained 12 months post-training. There were no intervention-related serious adverse effects.

CONCLUSIONS

The results are inconclusive. PBT may help to prevent falls in daily life poststroke, but ongoing training may be required to maintain the benefits.

TRIAL REGISTRATION NUMBER

ISRCTN05434601; Results.

Dual-Task Walking in Challenging Environments in People with Stroke: Cognitive-Motor Interference and Task Prioritization

Cognitive-motor interference may contribute to the risk of falling in people with stroke, as may be the associated phenomenon of inappropriate task prioritization. Examining dual-task walking could provide valuable insights as to how to best evaluate and treat walking in people with stroke. This study aimed to examine the effect of different walking environments on cognitive-motor interference and task prioritization in dual-task walking in people with stroke. Using a repeated-measures design, cognitive-motor interference and task prioritization were assessed in 30 stroke survivors, while walking in a plain environment and in two challenging environments that were enriched with either stationary physical context or suddenly appearing projector-augmented context. All three walking environment conditions were performed with and without a concurrent serial-3 subtraction task. We found stronger cognitive-motor interference for the two challenging environments than for the plain walking environment. Cognitive-motor interference did not differ between challenging walking environments, but task prioritization did: motor performance was prioritized more in the environment with physical context than in the environment with projector-augmented context and vice versa for cognitive-task performance. In conclusion, walking environment strongly influenced cognitive-motor interference and task prioritization during dual-task walking in people with stroke.

Walking adaptability therapy after stroke: study protocol for a randomized controlled trial

BACKGROUND

Walking in everyday life requires the ability to adapt walking to the environment. This adaptability is often impaired after stroke, and this might contribute to the increased fall risk after stroke. To improve safe community ambulation, walking adaptability training might be beneficial after stroke. This study is designed to compare the effects of two interventions for improving walking speed and walking adaptability: treadmill-based C-Mill therapy (therapy with augmented reality) and the overground FALLS program (a conventional therapy program). We hypothesize that C-Mill therapy will result in better outcomes than the FALLS program, owing to its expected greater amount of walking practice.

METHODS

This is a single-center parallel group randomized controlled trial with pre-intervention, post-intervention, retention, and follow-up tests. Forty persons after stroke (≥3 months) with deficits in walking or balance will be included. Participants will be randomly allocated to either C-Mill therapy or the overground FALLS program for 5 weeks. Both interventions will incorporate practice of walking adaptability and will be matched in terms of frequency, duration, and therapist attention. Walking speed, as determined by the 10 Meter Walking Test, will be the primary outcome measure. Secondary outcome measures will pertain to walking adaptability (10 Meter Walking Test with context or cognitive dual-task and Interactive Walkway assessments). Furthermore, commonly used clinical measures to determine walking ability (Timed Up-and-Go test), walking independence (Functional Ambulation Category), balance (Berg Balance Scale), and balance confidence (Activities-specific Balance Confidence scale) will be used, as well as a complementary set of walking-related assessments. The amount of walking practice (the number of steps taken per session) will be registered using the treadmill's inbuilt step counter (C-Mill therapy) and video recordings (FALLS program). This process measure will be compared between the two interventions.

DISCUSSION

This study will assess the effects of treadmill-based C-Mill therapy compared with the overground FALLS program and thereby the relative importance of the amount of walking practice as a key aspect of effective intervention programs directed at improving walking speed and walking adaptability after stroke.

TRIAL REGISTRATION

Netherlands Trial Register NTR4030 . Registered on 11 June 2013, amendment filed on 17 June 2016.

Perturbation training to promote safe independent mobility post-stroke: study protocol for a randomized controlled trial

Background

Falls are one of the most common medical complications post-stroke. Physical exercise, particularly exercise that challenges balance, reduces the risk of falls among healthy and frail older adults. However, exercise has not proven effective for preventing falls post-stroke. Falls ultimately occur when an individual fails to recover from a loss of balance. Thus, training to specifically improve reactive balance control could prevent falls. Perturbation training aims to improve reactive balance control by repeatedly exposing participants to postural perturbations. There is emerging evidence that perturbation training reduces fall rates among individuals with neurological conditions, such as Parkinson disease. The primary aim of this work is to determine if perturbation-based balance training can reduce occurrence of falls in daily life among individuals with chronic stroke. Secondary objectives are to determine the effect of perturbation training on balance confidence and activity restriction, and functional balance and mobility.

Methods/design

Individuals with chronic stroke will be recruited. Participants will be randomly assigned to one of two groups: 1) perturbation training, or 2) ‘traditional’ balance training. Perturbation training will involve both manual perturbations (e.g., a push or pull from a physiotherapist), and rapid voluntary movements to cause a loss of balance. Training will occur twice per week for 6 weeks. Participants will record falls and activity for 12 months following completion of the training program. Standardized clinical tools will be used to assess functional balance and mobility, and balance confidence before and after training.

Discussion

Falls are a significant problem for those with stroke. Despite the large body of work demonstrating effective interventions, such as exercise, for preventing falls in other populations, there is little evidence for interventions that prevent falls post-stroke. The proposed study will investigate a novel and promising intervention: perturbation training. If effective, this training has the potential to not only prevent falls, but to also improve safe independent mobility and engagement in daily activities for those with stroke.

Trial registration

Current Controlled Trials: ISRCTN05434601.