Falls after stroke

Validity and Reliability of The 3-Meter Backward Walk Test in Individuals with Stroke

OBJECTIVES

The 3-m backward walk test (3MBWT) is used to evaluate neuromuscular control, proprioception, protective reflexes, fall risk and balance. The aim of our study was to reveal the test-retest reliability and validity of the 3MBWT in stroke patients.

MATERIALS AND METHODS

This study included a total of 41 stroke patients [age 59 (35-78) years]. 3MBWT, Berg Balance Scale (BBS), Timed Up and Go test (TUG) were applied to the patients. The second evaluation (retest) was carried out by the same physiotherapist two days following the first evaluation (test) in order to measure test-retest reliability.

RESULTS

Cronbach's alpha coefficient was found to be 0.974 (excellent). For intra-rater agreement, the ICC values in the individual test were 0.985. The SEM value was 1.11 sec, the MDC value was found to be 1.57 sec. A moderate correlation was revealed between the 3 m-backward walking speed and BBS (r: -0.691, p: 0.001) and TUG (r: 0.849, p: 0.001).

CONCLUSIONS

The 3MBWT was observed to be valid and reliable in stroke individuals. It is an effecive and reliable tool for measuring dynamic balance and falls in stroke.

Falls in hospital patients with acquired communication disability secondary to stroke: A systematic review and meta-analysis

BACKGROUND

Falls are a common safety incident in people with stroke. Studies report that between 14% and 65% of people with stroke fall at least once during their hospital admission. Risk factors for falls in people with stroke have been reported to include neglect, balance and dependence for activities of daily living. Communication disability has been identified as a risk factor for patient safety incidents in hospital that has not been closely examined as a potential risk factor for falls in people with stroke.

AIM

To determine the association between communication disability secondary to stroke and falls in people with stroke in hospital.

METHODS & PROCEDURES

Systematic searches of five electronic databases were conducted in June 2019 using the key concepts of 'falls' and 'stroke' (PROSPERO CRD 42019137199). Included studies provided comparative data of falls in patients with stroke with and without communication disability. The methodological quality of the studies was examined using the Quality Assessment Tool for Studies with Diverse Designs (QATSDD). Both a narrative synthesis and a meta-analysis were completed.

MAIN CONTRIBUTION

A total of 15 studies met the criteria for inclusion and 11 were included in a meta-analysis. Three studies found people with communication disability had an increased rate of falls in hospital. However, a meta-analysis showed no significant association between a non-specific classification of communication disability and an increased risk of falls. There was some indication from individual studies that higher risk of falls may be associated with severe communication disability, but there were insufficient data reported on the severity of the communication disability to draw robust conclusions.

CONCLUSION & IMPLICATIONS

The results of this systematic review suggest that a generic classification of communication disability following stroke is not a risk factor for falls. However, further research that is inclusive of this population and considers severity of communication disability more specifically is required. What this paper adds What is already known on the subject The association between communication disability following stroke and falls in hospital is unclear. The literature reports mixed results regarding the impact of a communication disability following stroke on falls risk or rates of falls during hospital admission. What this paper adds to existing knowledge This review is the first to bring together this diverse literature to examine the association between communication disability following stroke and falls in hospital. The results suggest that a generic classification of communication disability following stroke is not a risk factor for falls. What are the potential or actual clinical implications of this work? There is a possibility that moderate to severe communication disability may be related to falls in patients in hospital. Further research is indicated to be more inclusive of people with communication disability, including those with severe communication disability.

[Stroke aftercare : Treatment reality, challenges and future perspectives]

BACKGROUND

Registry data demonstrate a high risk of recurrent stroke and rehospitalization rates after first-time stroke in Germany compared to the international level. Meanwhile, a report of the Institute for Applied Quality Assurance in the Healthcare System (aQua institute) pointed out the potential for improvement of post-stroke care in Germany.

OBJECTIVE

To establish perspectives for improvement of outpatient post-stroke care in Germany.

METHODS

Critical discussion of important aspects of post-stroke care, presentation of the current structures of healthcare provision and possibilities for improvement of post-stroke care.

RESULTS

Post-stroke care in Germany is predominantly carried out by general practitioners. Currently, standard healthcare procedures do not provide a comprehensive supportive system of structured and cross-sectoral aftercare after ischemic stroke. Special attention must be paid to the treatment of cardiovascular risk factors according to the guidelines, a specific and rapid provision of assist devices and physiotherapy as well as prevention and treatment of stroke-associated complications. Previous investigations have revealed sometimes clear deficits in the provision of treatment. The reasons include but are not limited to sectoral barriers that are difficult to overcome. New concepts of post-stroke care for improvement of these deficits are currently undergoing clinical testing.

CONCLUSION

Ischemic stroke should be considered as a complex chronic disease and should be treated accordingly after discharge from acute inpatient treatment. Emphasis should be placed on the optimization of interdisciplinary and cross-sectoral cooperation and support for general practitioners in the outpatient post-stroke care. New concepts of post-stroke care have the potential for improvement of the current healthcare structures.

Determining the optimal dose of reactive balance training after stroke: study protocol for a pilot randomised controlled trial

INTRODUCTION

Falls risk poststroke is highest soon after discharge from rehabilitation. Reactive balance training (RBT) aims to improve control of reactions to prevent falling after a loss of balance. In healthy older adults, a single RBT session can lead to lasting improvements in reactive balance control and prevent falls in daily life. While increasing the dose of RBT does not appear to lead to additional benefit for healthy older adults, stroke survivors, who have more severely impaired balance control, may benefit from a higher RBT dose. Our long-term goal is to determine the optimal dose of RBT in people with subacute stroke. This assessor-blinded pilot randomised controlled trial aims to inform the design of a larger trial to address this long-term goal.

METHODS AND ANALYSIS

Participants (n=36) will be attending out-patient stroke rehabilitation, and will be randomly allocated to one of three groups: one, three or six RBT sessions. RBT will replace a portion of participants' regular physiotherapy so that the total physical rehabilitation time will be the same for the three groups. Balance and balance confidence will be assessed at: (1) study enrolment; (2) out-patient rehabilitation discharge; and (3) 6 months postdischarge. Participants will report falls and physical activity for 6 months postdischarge. Pilot data will be used to plan the larger trial (ie, sample size estimate using fall rates, and which groups should be included based on between-group trends in pre-to-post training effect sizes for reactive balance control measures). Pilot data will also be used to assess the feasibility of the larger trial (ie, based on the accrual rate, outcome completion rate and feasibility of prescribing specific training doses).

ETHICS AND DISSEMINATION

Institutional research ethics approval has been received. Study participants will receive a lay summary of results. We will also publish our findings in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04219696; Pre results.

External validation of the recurrent falls risk scale in community-dwelling stroke individuals

OBJECTIVE

To externally validate the Recurrent Fall Risk Scale (ReFR) in community-dwelling stroke survivors.

METHODS

Cohort of stroke survivors with independent gait ability recruited from a reference outpatient stroke clinic. Besides sociodemographic and clinical data, the following scales were used: Modified Barthel Index (mBI), ReFR scale and National Institutes of Health Stroke Scale (NIHSS). Participants were followed up for 12 months to record the incidence of falls. Accuracy of the ReFR scale was measured by the area under the ROC curve.

RESULTS

One hundred and thirteen individuals were recruited between April 2016 and November 2016: mean age 54 years (± 14), 55% women, median time since the last stroke 24 months (range 12 -48 months), posterior vascular territory affected in 35% of the sample. Median NIHSS was 3 (range 1 to 6), median mBI 49 (range 46-50), median ReFR 3 (range 2 to 5). During the follow-up period, 32 (33%) subjects had at least one fall and 18 (19%) were recurrent fallers (two or more falls). The accuracy of ReFR scale was 0.67 (95% CI = 0.54-0.79), p = 0.026.

CONCLUSION

This study externally validated the ReFR as a tool to predict recurrent falls in individuals after stroke.

Dynamic Stability and Trunk Control Improvements Following Robotic Balance and Core Stability Training in Chronic Stroke Survivors: A Pilot Study

Stroke survivors show greater postural oscillations and altered muscular activation compared to healthy controls. This results in difficulties in walking and standing, and in an increased risk of falls. A proper control of the trunk is related to a stable walk and to a lower falling risk; to this extent, rehabilitative protocols are currently working on core stability. The main objective of this work was to evaluate the effectiveness of trunk and balance training performed with a new robotic device designed for evaluation and training of balance and core stability, in improving the recovery of chronic stroke patients compared with a traditional physical therapy program. Thirty chronic stroke patients, randomly divided in two groups, either underwent a traditional rehabilitative protocol, or a robot-based program. Each patient was assessed before and after the rehabilitation and at 3-months follow-up with clinical and robot-based evaluation exercises focused on static and dynamic balance and trunk control. Results from clinical scores showed an improvement in both groups in balance and trunk control. Robot-based indices analysis indicated that the experimental group showed greater improvements in proprioceptive control, reactive balance and postural control in unstable conditions, compared to the control group, showing an improved trunk control with reduced compensatory strategies at the end of the training. Moreover, the experimental group had an increased retention of the benefits obtained with training at 3 months follow up. These results support the idea that such robotic device is a promising tool for stroke rehabilitation.

Intense and unpredictable perturbations during gait training improve dynamic balance abilities in chronic hemiparetic individuals: a randomized controlled pilot trial

Background

Previous studies have assessed the effects of perturbation training on balance after stroke. However, the perturbations were either applied while standing or were small in amplitude during gait, which is not representative of the most common fall conditions. The perturbations were also combined with other challenges such as progressive increases in treadmill speed.

Objective

To determine the benefit of treadmill training with intense and unpredictable perturbations compared to treadmill walking-only training for dynamic balance and gait post-stroke.

Methods

Twenty-one individuals post-stroke with reduced dynamic balance abilities, with or without a history of fall and ability to walk on a treadmill without external support or a walking aid for at least 1 min were allocated to either an unpredictable gait perturbation (Perturb) group or a walking-only (NonPerturb) group through covariate adaptive randomization. Nine training sessions were conducted over 3 weeks. NonPerturb participants only walked on the treadmill but were offered perturbation training after the control intervention. Pre- and post-training evaluations included balance and gait abilities, maximal knee strength, balance confidence and community integration. Six-week phone follow-ups were conducted for balance confidence and community integration. Satisfaction with perturbation training was also assessed.

Results

With no baseline differences between groups (p > 0.075), perturbation training yielded large improvements in most variables in the Perturb (p < 0.05, Effect Size: ES > .46) group (n = 10) and the NonPerturb (p ≤ .089, ES > .45) group (n = 7 post-crossing), except for maximal strength (p > .23) in the NonPerturb group. Walking-only training in the NonPerturb group (n = 8, pre-crossing) mostly had no effect (p > .292, ES < .26), except on balance confidence (p = .063, ES = .46). The effects of the gait training were still present on balance confidence and community integration at follow-up. Satisfaction with the training program was high.

Conclusion

Intense and unpredictable gait perturbations have the potential to be an efficient component of training to improve balance abilities and community integration in individuals with chronic stroke. Retrospective registration: ClinicalTrials.gov. March 18th, 2020. Identifier: NCT04314830.

Characteristics of proactive balance and gait performance in subacute stroke patients demonstrating varying reactive balance capacity: A research study

BACKGROUND

Persons with stroke (PwS) demonstrate impaired reactive balance control placing them at increased risk of falls. Yet, tests used in clinical practice to assess this risk usually rely on proactive balance control.

OBJECTIVE

To investigate differences in proactive balance in PwS with varying reactive balance capacity.

METHODS

Reactive balance control was assessed in 48 first-event subacute PwS by measuring multiple-step threshold and fall threshold in response to unannounced surface perturbations. They were classified as low-, medium- high- threshold fallers and non-fallers in accordance with the perturbation magnitude at which they were unable to maintain balance (fall threshold). Proactive balance control and gait performance were tested using the Berg Balance test, 10-meter walk test, 6-minute walk test and the Activities-specific Balance Confidence Scale (ABC).

RESULTS

PwS who demonstrated poor reactive balance capacity were also more impaired in their proactive balance and gait. Proactive balance and gait performance were significantly different between the 4 groups while ABC was not. The associations between reactive and proactive measures of balance were moderate (r = 0.53-0.67).

CONCLUSIONS

The moderate correlations between reactive and proactive balance control suggest the recruitment of different neural mechanisms for these two operations, highlighting the importance of assessing and treating reactive balance in clinics.

Functional electrical stimulation of the peroneal nerve improves post-stroke gait speed when combined with physiotherapy. A systematic review and meta-analysis

BACKGROUND

Functional electrical stimulation (FES) applied to the paretic peroneal nerve has positive clinical effects on foot drop secondary to stroke.

OBJECTIVE

To evaluate the effectiveness of FES applied to the paretic peroneal nerve on gait speed, active ankle dorsiflexion mobility, balance, and functional mobility.

METHODS

Electronic databases were searched for articles published from inception to January 2020. We included randomized controlled trials or crossover trials focused on determining the effects of FES combined or not with other therapies in individuals with foot drop after stroke. Characteristics of studies, participants, comparison groups, interventions, and outcomes were extracted. Statistical heterogeneity was assessed with the I² statistic.

RESULTS

We included 14 studies providing data for 1115 participants. FES did not enhance gait speed as compared with conventional treatments (i.e., supervised/unsupervised exercises and regular activities at home). FES combined with supervised exercises (i.e., physiotherapy) was better than supervised exercises alone for improving gait speed. We found no effect of FES combined with unsupervised exercises and inconclusive effects when FES was combined with regular activities at home. When FES was compared with conventional treatments, it improved ankle dorsiflexion, balance and functional mobility, albeit with high heterogeneity for these last 2 outcomes.

CONCLUSIONS

This meta-analysis revealed low quality of evidence for positive effects of FES on gait speed when combined with physiotherapy. FES can improve ankle dorsiflexion, balance, and functional mobility. However, considering the low quality of evidence and the high heterogeneity, these results must be interpreted carefully.

Mixed slip-trip perturbation training for improving reactive responses in people with chronic stroke

This study determined the effect of mixed (slip- and trip-like stance perturbation) training on reactive responses in people with chronic stroke (PwCS) and examined modulation of their reactive responses on higher intensity perturbations posttraining (scaling). Twelve PwCS were exposed to consecutive blocks of treadmill-based slip-like and trip-like perturbations and mixed-stance perturbations. A higher intensity trial was provided postblock and postmixed training. Postural stability [center-of-mass position (CoMP) and velocity (CoMV)], compensatory step length, step count, and trunk angle were examined. PwCS demonstrated an anterior positioning of the CoM, increased step length, and reduced compensatory step count with slip-like block training (P < 0.05). Trip-like block training resulted in reductions in step count, step length, and trunk angle (P < 0.05); however, CoMP remained unchanged (P > 0.05). With mixed training, there was a decrease rather than an increase in step length for slip-like perturbations but a continued decrease in step length and trunk angle was seen on trip-like perturbations (P < 0.05); however, CoMP and step count remained unchanged for both. For both perturbations, the higher intensity trials demonstrated no change from the last block trial. Postmixed block, the higher intensity trial demonstrated an increase only in step count on trip-like perturbation. Between postblock and postmixed higher intensity trials, an increase in step count and decrease in step length was noted only for slip-like perturbations. Block training with slip- and trip-like stance perturbations can enhance reactive responses among PwCS. Although mixed perturbation training continued to improve trip-induced adaptation, prior slip-induced adaptive changes were not maintained and further slip-adaptation was not seen. PwCS demonstrated partial scaling of reactive responses postblock and postmixed training.NEW & NOTEWORTHY Block perturbation training led to development of favorable reactive responses to counteract treadmill-based, slip-like and trip-like stance perturbations among people with chronic stroke. During mixed block, previously acquired adaptive changes in reactive responses from slip-block training were not maintained, probably due to interference offered by trip block. Instead, on trip-like perturbations, trip block-induced adaptation was maintained and continued to show further improvement. Our findings might provide future direction for designing effective mixed perturbation training paradigms to counteract both opposing perturbation types.

Selection of the Better Dual-Timed Up and Go Cognitive Task to Be Used in Patients With Stroke Characterized by Subtraction Operation Difficulties

Background: The Timed Up and Go Test (TUG) with serial subtraction is commonly used to assess cognitive-dual task performance during walking for fall prediction. Some stroke patients cannot perform number subtraction and it is unclear which cognitive task can be used to substitute for the subtraction task in the TUG test. The aim of this study was to determine the type of cognitive task that produced the highest decrease on both motor and cognitive performances during TUG-dual in stroke patients.

Methods: A total of 23 persons with stroke but capable of completing subtraction (ST) and 19 persons with subtraction operation difficulties (SOD) participated. Both groups have a similar age range (ST: 59.3 ± 10.4 years and SOD: 62.0 ± 6.8 years) and stroke onset duration (ST: 44.13 ± 62.29 months and SOD: 42.34 ± 39.69 months). The participants performed TUG without a cognitive task (TUG-single) followed by a cognitive task when seated (cognitive-single). In addition, TUG with a cognitive task (TUG-dual) was performed, with the activity randomly selected from four cognitive tasks, including alternate reciting, auditory working memory, clock task, and phonologic fluency. The main outcome variables—TUG duration measured by OPAL accelerometer and cognitive-dual task effect (DTE)—were analyzed using repeated-measures analyses of variance (ANOVA).

Results: The number of correct responses when seated were significantly lower in the SOD as compared to the ST (p < 0.05) during all cognitive tasks, except the phonologic fluency. During TUG-cognitive, TUG duration in the ST was significantly longer for all cognitive tasks compared with TUG-single (p < 0.0001), whereas TUG duration in the SOD was significantly increased only during the phonologic fluency task (p < 0.01). In the ST, there was a significant difference in cognitive DTE between the subtraction and the phonologic fluency tasks (p < 0.01). The highest cognitive cost was found in the subtraction task, whereas the highest cognitive benefit was shown in the phonologic fluency task. No significant cognitive DTE was found among the cognitive tasks in the SOD.

Conclusion: For stroke persons with SOD, phonologic fluency is suitable to be used in the TUG-cognitive assessment. In contrast, subtraction (by 3s) is recommended for the assessment of TUG-cognitive in stroke persons who can perform subtraction.

Open-loop and closed-loop control of posture: Stabilogram-diffusion analysis of center-of-pressure trajectories among people with stroke

Many people with stroke (PwS) demonstrate reduced balance and increased postural sway afterwards, which may ultimately lead to falls and injury. In this study, we aimed to better understand postural sway behavior and the mechanisms of balance control by examining balance in upright standing among PwS using methods from statistical mechanics i.e., the Stabilogram diffusion analysis (SDA). Center-of-pressure displacements while standing still were measured in 25 PwS and 11 healthy subjects. The traditional postural sway parameters were measured, and the SDA was used to characterize balance control in eyes-open and eyes-closed conditions. We found that PwS demonstrated significantly greater postural sway in the mediolateral and anterior-posterior directions and significantly higher SDA short-term diffusion coefficients and critical displacement in both eyes-open and eyes-closed conditions. There was also a significant group-by-condition interaction, whereas PwS demonstrated more sway in the eyes-closed condition. The SDA analysis revealed unstable behavior during short-term intervals, interpreted as larger distance of sway until closed-loop control took place. This significant group-by-condition interaction suggests that PwS have a significantly greater reliance on visual input compared with healthy subjects.

A randomized controlled trial of motor imagery combined with structured progressive circuit class therapy on gait in stroke survivors

Structured Progressive Circuit Class Therapy (SPCCT) was developed based on task-oriented therapy, providing benefits to patients’ motivation and motor function. Training with Motor Imagery (MI) alone can improve gait performance in stroke survivors, but a greater effect may be observed when combined with SPCCT. Health education (HE) is a basic component of stroke rehabilitation and can reduce depression and emotional distress. Thus, this study aimed to investigate the effect of MI with SPCCT against HE with SPCCT on gait in stroke survivors. Two hundred and ninety stroke survivors from 3 hospitals in Yangon, Myanmar enrolled in the study. Of these, 40 stroke survivors who passed the selection criteria were randomized into an experimental (n = 20) or control (n = 20) group. The experimental group received MI training whereas the control group received HE for 25 minutes prior to having the same 65 minutes SPCCT program, with both groups receiving training 3 times a week over 4 weeks. Temporo-spatial gait variables and lower limb muscle strength of the affected side were assessed at baseline, 2 weeks, and 4 weeks after intervention. After 4 weeks of training, the experimental group showed greater improvement than the control group in all temporospatial gait variables, except for the unaffected step length and step time symmetry which showed no difference. In addition, greater improvements of the affected hip flexor and knee extensor muscle strength were found in the experimental group. In conclusion, a combination of MI with SPCCT provided a greater therapeutic effect on gait and lower limb muscle strengths in stroke survivors.

[Modern aspects of the pathophysiology of walking disorders and their rehabilitation in post-stroke patients]

The problem of rehabilitation of post-stroke patients with motor deficit remains relevant with growing prevalence of disability and decreasing mortality, despite all measures aimed at stroke prevention and morbidity reduction. One of the most common consequences of stroke is gait impairment as a result of spastic paresis of the lower limb (decreased gait velocity, shortened step, excessive loading of intact limb etc.), which leads to significant maladaptation, increased risk of falls, decrease in quality of life. The article presents a detailed review of motor action in normal and pathologic conditions, analysis of neuronal structures involved into a movement act in healthy individuals and in stroke patients, current aspects of gait pathophysiology, characteristics of post-stroke gait (speed and asymmetry of gain, balance control impairment). A separate paragraph is devoted to gait recovery after stroke with analysis of existing and developing strategies of rehabilitation, aimed at the improvement of vertical posture, balance control and movement, condition, tone and functioning of skeletal muscles. Authors also analyze new research information on the efficacy of botulinum toxin preparations and programs of Guided Self-Rehabilitation Contracts (GSC), present the results of clinical trials demonstrating the efficacy of combination of these two methods.

Effects of bodyweight support and guidance force on muscle activation during Locomat walking in people with stroke: a cross-sectional study

BACKGROUND

Locomat is a robotic exoskeleton providing guidance force and bodyweight support to facilitate intensive walking training for people with stroke. Although the Locomat has been reported to be effective in improving walking performance, the effects of training parameters on the neuromuscular control remain unclear. This study aimed to compare the muscle activities between Locomat walking and treadmill walking at a normal speed, as well as to investigate the effects of varying bodyweight support and guidance force on muscle activation patterns during Locomat walking in people with stroke.

METHODS

A cross-sectional study design was employed. Participants first performed an unrestrained walking on a treadmill and then walked in the Locomat with different levels of bodyweight support (30% or 50%) and guidance force (40% or 70%) at the same speed (1.2 m/s). Surface electromyography (sEMG) of seven muscles of the affected leg was recorded. The sEMG envelope was time-normalised and averaged over gait cycles. Mean sEMG amplitude was then calculated by normalising the sEMG amplitude with respect to the peak amplitude during treadmill walking for statistical analysis. A series of Non-parametric test and post hoc analysis were performed with a significance level of 0.05.

RESULTS

Fourteen participants with stroke were recruited at the Yangzhi Affiliated Rehabilitation Hospital of Tongji University (female n = 1; mean age 46.1 ± 11.1 years). Only the mean sEMG amplitude of vastus medialis oblique during Locomat walking (50% bodyweight support and 70% guidance force) was significantly lower than that during treadmill walking. Reducing both bodyweight and guidance increased muscle activity of gluteus medius and tibialis anterior. Activity of vastus medialis oblique muscle increased as bodyweight support reduced, while that of rectus femoris increased as guidance force decreased.

CONCLUSIONS

The effects of Locomat on reducing muscle activity in people with stroke were minimized when walking at a normal speed. Reducing bodyweight support and guidance force increased the activity of specific muscles during Locomat walking. Effects of bodyweight support, guidance force and speed should be taken into account when developing individualized Locomat training protocols for clients with stroke.

Sex differences in stroke

Sex disparities within the field of stroke, including subarachnoid hemorrhages (SAHs), have been in focus during the last 2 decades. It is clear that stroke incidence is higher in men, and also that men have their first stroke earlier than women. On the other hand, women have more severe strokes, mainly because cardioembolic strokes are more common in women. This leads to higher case fatality and worse functional outcome in women. It has often been pointed out that women more often have nontraditional stroke symptoms, and therefore may seek medical help later. After discharge from the hospital, female stroke survivors live alone in many cases and are dependent on external care. Therefore, these women frequently rate their quality of life (QoL) lower than men do. Female spouses more often provide help to their male stroke survivors than the reverse, and they accept a heavier burden. These caregivers are at high risk for depression, low QoL, and low psychologic wellbeing. SAH is a special form of stroke, often caused by a ruptured aneurysm. It is about 20% more common in women. The case fatality is high, but does not differ between the sexes.

Post-stroke patients with moderate function have the greatest risk of falls: a National Cohort Study

BACKGROUND

Stroke patients have increased risks of falls. We examined national registry data to evaluate the association between post-stroke functional level and the risk of low falls among post-stroke patients.

METHODS

This retrospective cohort study analyzed data from national registries to examine the risk factors for post-stroke falls. Data for patients who suffered ischemic strokes and survived the index hospital admission was obtained from the Singapore National Stroke Registry and matched to the National Trauma Registry, from 2011 to 2015. The primary outcome measure was a low fall (fall height ≤ 0.5 m). Competing risk analysis was performed to examine the association between functional level (by modified Rankin score [mRS] at discharge) and the risk of subsequent low falls.

RESULTS

In all, 2255 patients who suffered ischemic strokes had recorded mRS. The mean age was 66.6 years and 58.5% were men. By the end of 2015, 54 (2.39%) had a low fall while 93 (4.12%) died. After adjusting for potential confounders, mRS was associated with fall risk with an inverted U-shaped relationship. Compared to patients with a score of zero, the sub-distribution hazard ratio (SHR) increased to a maximum of 3.42 (95%CI:1.21-9.65, p = 0.020) for patients with a score of 2. The SHR then declined to 2.45 (95%CI:0.85-7.12, p = 0.098), 2.86 (95%CI:0.95-8.61, p = 0.062) and 1.93 (95%CI:0.44-8.52, p = 0.38) for patients with scores of 3, 4 and 5 respectively.

CONCLUSIONS

An inverted U-shaped relationship between functional status and fall risk was observed. This is consistent with the complex interplay between decreasing mobility (hence decreased opportunity to fall) and increasing susceptibility to falls. Fall prevention intervention could be targeted accordingly. (263 words).

Individualized feedback to change multiple gait deficits in chronic stroke

Background

Walking deficits in people post-stroke are often multiple and idiosyncratic in nature. Limited patient and therapist resources necessitate prioritization of deficits such that some may be left unaddressed. More efficient delivery of therapy may alleviate this challenge. Here, we look to determine the utility of a novel principal component-based visual feedback system that targets multiple, patient-specific features of gait in people post-stroke.

Methods

Ten individuals with stroke received two sessions of visual feedback to attain a walking goal. This goal consisted of bilateral knee and hip joint angles of a typical ‘healthy’ walking pattern. The feedback system uses principal component analysis (PCA) to algorithmically weight each of the input features so that participants received one stream of performance feedback. In the first session, participants had to explore different patterns to achieve the goal, and in the second session they were informed of the goal walking pattern. Ten healthy, age-matched individuals received the same paradigm, but with a hemiparetic goal (i.e. to produce the pattern of an exemplar stroke participant). This was to distinguish the extent to which performance limitations in stroke were due neurological injury or the PCA based visual feedback itself.

Results

Principal component-based visual feedback can differentially bias multiple features of walking toward a prescribed goal. On average, individuals with stroke typically improved performance via increased paretic knee and hip flexion, and did not perform better with explicit instruction. In contrast, healthy people performed better (i.e. could produce the desired exemplar stroke pattern) in both sessions, and were best with explicit instruction. Importantly, the feedback for stroke participants accommodated a heterogeneous set of walking deficits by individually weighting each feature based on baseline walking.

Conclusions

People with and without stroke are able to use this novel visual feedback to train multiple, specific features of gait. Important for stroke, the PCA feedback allowed for targeting of patient-specific deficits. This feedback is flexible to any feature of walking in any plane of movement, thus providing a potential tool for therapists to simultaneously target multiple aberrant features of gait.

Factors affecting fear of falls in patients with chronic stroke

Objective: The aim of this study was to find the factors associated with fear of falls in patients having chronic stroke.Methods: Inclusion criterion was subjects with cerebral stroke for more than 3 months. A structured interview of 82 subjects was conducted with a questionnaire with questions regarding personal factors such as gender, side affected, number of comorbidities, and setting of physical therapy sessions. Depression was assessed using Patient Health Questionnaire-9, lower extremity motor function was assessed using Fugl-Meyer scale, and functional mobility was assessed using Timed Up and Go. Chi-square analysis was done on the above factors to find significant factors followed by logistic regression of the factors found significant in Chi square.Results: Lower extremity Fugl-Meyer score was significantly associated with fear of falls (p value 0.047 with Odds ratio of 1.136, 95% CI 1.002-1.287) in patients having chronic stroke while treatment factors, such as setting of physical therapy sessions, and personal factors, such as gender, side affected, number of comorbidities, depression, functional mobility, or use of walking aid, were not found to have significant association.Conclusion: The lower extremity Fugl-Meyer score is associated with fear of falls in patients having chronic stroke.

Improvements in balance reaction impairments following reactive balance training in individuals with sub-acute stroke: A prospective cohort study with historical control

Background: Reactive balance training (RBT) has been previously found to reduce fall risk in individuals with sub-acute stroke; however, our understanding of the effects of RBT on specific balance impairments is lacking.Objective: To quantify changes in common balance reaction impairments in individuals with sub-acute stroke resulting from RBT, relative to traditional balance training, using a prospective cohort study design with a historical control group.Methods: Individuals with sub-acute stroke completed either RBT or traditional balance training as part of their routine care during physiotherapy in inpatient rehabilitation. Reactive balance control was assessed using lean-and-release perturbations pre-intervention, post-intervention, and 6-months post-intervention (follow-up). Individuals with impaired balance reactions (delayed foot-off times, slide steps, and/or a preference for stepping with the preferred limb) at the pre-intervention assessment were identified using video and force plate data. Outcome measures (foot-off times, frequency of trials with slide steps, and stepping with the preferred limb) from the RBT participants with impaired reactions were compared for each of the three assessments to the mean values for the participants with impaired reactions in the historical control group.Results: Improvements were observed in all outcome measures for the RBT participants between pre-intervention and post-intervention, and/or between post-intervention and follow-up. These improvements were generally equivalent to, if not better than, the improvements demonstrated by the historical control group.Conclusions: Findings further support the use of RBT for post-stroke inpatient rehabilitation, and provide insight into specific balance reaction impairments that are improved by RBT.

Anterior fall-recovery training applied to individuals with chronic stroke

BACKGROUND

To study the effects of the initial stepping limb on anterior fall-recovery performance and kinematics, as well as to determine the benefits of fall-recovery training on those outcomes in individuals with chronic stroke.

METHODS

Single-group intervention of 15 individuals with chronic stroke who performed up to six sessions of fall-recovery training. Each session consisted of two progressions of treadmill-induced perturbations to induce anterior falls from a standing position. Progressions focused on initial steps with the paretic or non-paretic limb. Fall-recovery performance (the highest disturbance level achieved and the proportion of successful recoveries), as well as step and trunk kinematics were compared between the initial stepping limbs on the first session. Limb-specific outcomes were also compared between the first and last training sessions.

FINDINGS

There were no between-limb differences in fall-recovery performance in the first session. With training, participants successfully recovered from a higher proportion of falls (p's = 0.01, Cohen's d's > 0.7) and progressed to larger perturbation magnitudes (p's < 0.06, d's > 0.5). Initial steps with the paretic limb were wider and shorter relative to the center of mass (p's < 0.06, d's > 0.5). With training, initial paretic-limb steps became longer relative to the CoM (p = 0.03, d = 0.7). Trunk forward rotation was reduced when first stepping with the non-paretic limb (p = 0.03, d = 0.6).

INTERPRETATION

The initial stepping limb affects relevant step kinematics during anterior fall recovery. Fall-recovery training improved performance and select kinematic outcomes in individuals with chronic stroke.

Transfer of reactive balance adaptation from stance-slip perturbation to stance-trip perturbation in chronic stroke survivors

BACKGROUND

Chronic stroke survivors demonstrate the potential to acquire reactive adaptations to external perturbations. However, such adaptations in postural stability and compensatory stepping responses are perturbation-type specific and the ability to generalize such adaptation to an opposing perturbation has not been studied.

OBJECTIVE

The study aimed to examine whether improved reactive balance control acquired through prior slip-perturbation training would positively transfer to, or interfere with, the reactive response to an unexpected novel trip.

METHODS

Twenty-six chronic stroke survivors were assigned to either the training group (TR) who received treadmill-induced slips (12 m/s2) while standing followed by a novel trip (16.8 m/s2) or the control group (TC) who experienced a single unannounced trip. The primary outcome measure was postural stability (examined by relative center of mass position (RCoMP) and velocity (RCoMV)) with step length and trunk angle being secondary measures. Perturbation outcome (fall vs recovery) and number of compensatory steps were also recorded.

RESULTS

The TR group showed an anterior shift in RCoMP via longer compensatory backward step and reduced number of steps from first to last slip-perturbation (p < 0.05). Post-slip adaptation, the TR group exhibited a more posterior RCoMP on the novel trip along with a longer forward step and decreased trunk flexion compared to the TC group (p < 0.05).

CONCLUSIONS

Chronic stroke survivors demonstrated improved direction-specific compensatory stepping response on a novel trip-perturbation following reactive adaptation to large-magnitude, stance-slip perturbation training.The present study investigates the ability of chronic stroke survivors to generalize motor adaptation from stance-slip perturbation training to a novel, diametrically opposing trip-perturbation. We report that people with chronic hemi-paretic stroke could execute the acquired adaptation in reactive postural stability to improve reactive stepping responses to a novel stance-trip perturbation via generation of a direction-specific effective compensatory stepping response, such that the training group demonstrated a longer forward compensatory step and better control of postural stability than the control group.

Body weight support-Tai Chi footwork for balance of stroke survivors with fear of falling: A pilot randomized controlled trial

BACKGROUND AND PURPOSE

Balance impairment is the predominant risk factor for falls in stroke survivors. This study examined the effects of body weight support-Tai Chi (BWS-TC) footwork on balance control among stroke survivors with fear of falling (FOF).

MATERIALS AND METHODS

Twenty-eight stroke survivors with FOF were randomly allocated to either control or BWS-TC groups. Those in BWS-TC underwent Tai Chi training for 12 weeks. Outcomes were assessed in all participants by evaluation of the limits of stability test, modified clinical test of sensory integration of balance, fall risk index, and Fugl-Meyer assessment of lower limbs at baseline and 12 weeks.

RESULTS

The BWS-TC group displayed significant enhancement in dynamic control and vestibular and somatosensory integration.

CONCLUSION

BWS-TC may enhance dynamic control and sensory integration of balance and reduce the risk of fall in stroke survivors with FOF.

Using Functional Independence Measure Subscales to Predict Falls-Rapid Assessment

BACKGROUND

Falls remain a major issue in inpatient rehabilitation. Decreased scores on the Functional Independence Measure (FIM), given to every patient, have been shown to predict falls risk.

PURPOSE

The aim of the study was to extend previous research using FIM to predict falls by using only subscales assessed earliest during admissions to indicate high risk of falls.

DESIGN

Retrospective cohort study.

METHODS

Two consecutive samples of patients (n1 = 1,553, n2 = 12,301) admitted to a rehabilitation hospital over 9-month and 5-year periods, respectively, were used to evaluate the predictive utility of using only a small number of FIM subscales. Subscales were selected from those assessed earliest and were related to previously published research on falls risk factors. The metric was developed using a historical data set and was validated with a second, separate group of patients. Receiver operating characteristic curves were used to evaluate predictive utility.

FINDINGS

The combination of Toileting and Expression subscales yielded a comparable area under the curve to the full FIM, and both were greater than the existing method of falls risk assessment. Likelihood of falling was strongly linearly related to score on the Toileting/Expression metric.

CONCLUSIONS

The sum of two FIM subscales can be used to predict which patients may fall during their stay in a rehabilitation hospital.

CLINICAL RELEVANCE

The FIM scores are assessed early during a patient's stay, are required for all Medicare patients, and may be useful for simple, rapid, and accurate assignment of falls risk.

Educational and Exercise Intervention to Prevent Falls and Improve Participation in Subjects With Neurological Conditions: The NEUROFALL Randomized Controlled Trial

Background: Falls, mobility impairments and lack of social support lead to participation restrictions in people with neurological conditions. The aim of this multicenter, single blinded randomized controlled trial was to test whether an educational program focusing on fall prevention and safe mobility reduces falls and increases social participation among people with neurological conditions. Methods: Ninety people with Stroke (n = 25), multiple sclerosis (n = 33) and Parkinson disease (n = 32), median age 63 (31-89), were randomized. A permuted block algorithm stratified by field center was used to allocate participants to an education group (EG, n = 42) consisting of an educational program focused on fall prevention and tailored balance exercises and a control group (CG, n = 48) receiving usual treatments. After baseline assessment, each participants was followed for 6 months with telephone contacts by blinded interviewers. Being fallers (>1 fall) and time to become a faller were used as primary outcomes. Community Integration Questionnaire (CIQ) and Instrumental Activities of Daily Living (IADL) scales assessed treatment effects on social integration and daily living activities. Results: Over a median (Interquartile Range) follow-up of 189 (182-205) days, [EG = 188 (182-202), CG = 189 (182-209)] fallers were 10 in the CG and 11 in the EG (hazard ratio 0.95, 95% confidence interval (CI) 0.45 to 2.5; P = 0.94). At follow-up the EG scored significantly better than CG on the CIQ (+1.7 points, CI: 0.1 to 3.3) and IADL (+2.2 points, CI: 0.4 to 4.0). Conclusions: This educational program did not reduce the risk of falls but it improved the ability to carry out activities of daily living and decreased participation restrictions in people with neurological conditions.

Insufficient Balance Recovery Following Unannounced External Perturbations in Persons With Stroke

Background. Persons with stroke (PwS) are at increased risk of falls, especially toward the paretic side, increasing the probability of a hip fracture. The ability to recover from unexpected loss of balance is a critical factor in fall prevention. Objectives. We aimed to compare reactive balance capacity and step kinematics between PwS and healthy controls. Methods. Thirty subacute PwS and 15 healthy controls were exposed to forward, backward, right, and left unannounced surface translations in 6 increasing intensities while standing. Single step threshold, multiple step threshold, and fall threshold (ie, perturbation intensity leading to a fall into harness system) were recorded as well as reactive step initiation time, step length, and step velocity. Results. Twenty-five PwS fell into harness system during the experiment while healthy controls did not fall. Fourteen out of 31 falls occurred in response to surface translations toward the nonparetic side, that is, falling toward the paretic side. Compared with healthy controls, PwS demonstrated significantly lower fall threshold and multiple step threshold in response to forward, backward, and lateral surface translations. Impairments were more pronounced in response to forward surface translation and toward the nonparetic side (ie, loss of balance toward the paretic side). A trend toward significant shorter step length in response to lateral surface translations was found in PwS compared with healthy controls. Conclusions. Findings highlight the importance of assessing reactive balance capacity in response to perturbations in different directions and intensities in addition to the routine assessment in PwS.

Comparable walking gait performance during executive and non-executive cognitive dual-tasks in chronic stroke: A pilot study

BACKGROUND

Falls are a serious problem among stroke survivors due to subsequent injuries, recovery setbacks, dependence, and mortality. A growing body of dual-task (DT) studies suggests a role of executive functions in gait control and falls, particularly in subacute stroke. However, few studies have compared distinct executive and non-executive tasks, nor their effects on chronic stroke gait.

RESEARCH QUESTION

The purpose of this cross-sectional study was to compare the effects of distinct working memory (2-back) and inhibition (Stroop) tasks on walking gait performance in chronic stroke survivors.

METHODS

A pilot sample of chronic stroke survivors (n = 11, 8 males, mean age = 70.91, 6-12months post-stroke event) and age-matched healthy controls (n = 13, 4 male; mean age = 68.46) were tested. Gait performance (speed, stride time, stride time variability, stride length and stride length variability) was measured using 2 wireless inertial measurement sensors under 4 walking conditions: 1) preferred walking (single-task: ST), 2) walking with a 2-back DT, 3) walking with a Stroop DT, and 4) walking with a non-executive motor response DT. The secondary tasks were also carried out in both ST (seated) and DT conditions, to examine bidirectional effects.

RESULTS

While the stroke survivor sample had a slower gait speed across conditions and tasks, there were no significant differences between the groups [F(1, 22) = 1.13, p =.299, η²p =  .049] on the spatial or temporal gait characteristics recorded: gait performance was maintained during executive and non-executive DTs. In addition, we did not find a significant effect of group on cognitive task performance (all p > .052). However, we observed a cost in accuracy on the 2-back DT for both groups, suggesting resource overlap and greater cognitive load (all t > 19.72, all p <  .001).

SIGNIFICANCE

Our gait data contradict previous studies evidencing impaired gait post-stroke, suggesting functional recovery in this chronic stroke sample.

Falls and Fractures in Diabetes-More than Bone Fragility

PURPOSE OF REVIEW

Based on a systematic literature search, we performed a comprehensive review of risk factors for falls and fractures in patients with diabetes.

RECENT FINDINGS

Patients with diabetes have an increased risk of fractures partly explained by increased bone fragility. Several risk factors as altered body composition including sarcopenia and obesity, impaired postural control, gait deficits, neuropathy, cardiovascular disease, and other co-morbidities are considered to increase the risk of falling. Diabetes and bone fragility is well studied, but new thresholds for fracture assessment should be considered. In general, the risk factors for falls in patients with diabetes are well documented in several studies. However, the fall mechanisms among diabetic patients have only been assessed in few studies. Thus, a gab of knowledge exits and may influence the current understanding and treatment, in order to reduce the risk of falling and thereby prevent fractures.

Rehabilitation Indices associated with sustaining a minimal trauma fracture within 12 months of a stroke in Western Australia

OBJECTIVE

To identify Rehabilitation Indices associated with a minimal trauma fracture (MTF) within 12 months poststroke.

METHODS

Retrospective case-control study. Stroke survivors with MTF were matched 5:1 with stroke survivors without MTF. Logistic regression determined whether Rehabilitation Indices, such as Physiotherapy Ambulation score (PhysioAmb), were associated with a MTF within 12 months poststroke.

RESULTS

Forty-three stroke survivors (mean age: 79.8; 55.81% female) experienced a MTF (median time to MTF of 1.79 years [IQR 0.70, 4.48]). Those with a MTF within 12 months had lower PhysioAmb (4.53 vs 8.29) and Berg Balance Scale (BBS; 12.25 vs 40.57) scores on admission, lower BBS score on discharge (30.33 vs 49.29) and a greater change in PhysioAmb (+5.67 vs +3.24) and BBS scores (+21.50 vs +8.71) after rehabilitation, all P < 0.05. Greater changes in PhysioAmb score increased the odds of a MTF within 12 months by 18%.

CONCLUSION

Rehabilitation Indices are associated with a MTF within 12 months poststroke.

Real-time foot clearance biofeedback to assist gait rehabilitation following stroke: a randomized controlled trial protocol

Background

The risk of falling is significantly higher in people with chronic stroke and it is, therefore, important to design interventions to improve mobility and decrease falls risk. Minimum toe clearance (MTC) is the key gait cycle event for predicting tripping-falls because it occurs mid-swing during the walking cycle where forward velocity of the foot is maximum.

High forward velocity coupled with low MTC increases the probability of unanticipated foot-ground contacts. Training procedures to increase toe-ground clearance (MTC) have potential, therefore, as a falls-prevention intervention. The aim of this project is to determine whether augmented sensory information via real-time visual biofeedback during gait training can increase MTC.

Methods

Participants will be aged > 18 years, have sustained a single stroke (ischemic or hemorrhagic) at least six months previously, able to walk 50 m independently, and capable of informed consent. Using a secure web-based application (REDCap), 150 participants will be randomly assigned to either no-feedback (Control) or feedback (Experimental) groups; all will receive 10 sessions of treadmill training for up to 10 min at a self-selected speed over 5–6 weeks. The intervention group will receive real-time, visual biofeedback of MTC during training and will be asked to modify their gait pattern to match a required “target” criterion. Biofeedback is continuous for the first six sessions then progressively reduced (faded) across the remaining four sessions. Control participants will walk on the treadmill without biofeedback. Gait assessments are conducted at baseline, immediately following the final training session and then during follow-up, at one, three, and six months. The primary outcome measure is MTC. Monthly falls calendars will also be collected for 12 months from enrolment.

Discussion

The project will contribute to understanding how stroke-related changes to sensory and motor processes influence gait biomechanics and associated tripping risk. The research findings will guide our work in gait rehabilitation following stroke and may reduce falls rates. Treadmill training procedures incorporating continuous real-time feedback may need to be modified to accommodate stroke patients who have greater difficulties with treadmill walking.

Trial registration

Australia New Zealand Clinical Trials Registry, ACTRN12617000250336. Registered on 17 February 2017.

A functional recovery profile for patients with stroke following post-acute rehabilitation care in Taiwan

BACKGROUND

Functional impairment is frequently seen in patients with stroke. Although the progression of functional recovery after stroke has been proposed, the recovery profile after acute stroke is not well described. The objective of this study is to investigate functional recovery in stroke patients entering post-acute rehabilitation care.

METHODS

A retrospective cohort study collected the data of patients who entered the stroke Post-acute Care (PAC) programs. Ninety-five patients after stroke with a modified Ranking Scale (mRS) score of 3-4 who were referred to a post-acute care unit for intensive rehabilitation were recruited. The patients underwent functional, quality of life, and neuropsychological evaluation tests at admission and before discharge. The test scores before discharge were used as outcome variables and were compared with the test scores at admission to show functional recovery.

RESULTS

The average length of stay was 58.15 days. After an intensive rehabilitation intervention, significant improvements were observed in all test scores. Additionally, a significant removal rate for nasogastric tubes (p = 0.000) and Foley catheters (p = 0.003) was found at discharge.

CONCLUSION

This study showed that the PAC rehabilitation unit was beneficial for patients with acute stroke who had functional impairments. The study results may call for further investigation to identify and develop better models for the delivery of rehabilitation in the stroke PAC unit.

The development and feasibility of treadmill-induced fall recovery training applied to individuals with chronic stroke

Background

Exercise has failed to reduce falls in those with chronic stroke. A limitation of traditional exercise is that the motor responses needed to prevent a fall are not elicited (i.e. they lack processing specificity). Balance reactions often require compensatory steps. Therefore, interventions that target such steps have the potential to reduce falls. Computerized treadmills can deliver precise, repeatable, and challenging perturbations as part of a training protocol. The objective of this study was to develop and determine the feasibility of such training applied to those with chronic stroke. We developed the training to address specificity, appropriate duration and repetition, and progressive overloading and individualization. We hypothesized that our intervention would be acceptable, practical, safe, and demonstrate initial signs of efficacy.

Methods

In this single-arm study, thirteen individuals with chronic stroke (29–77 years old, 2–15 years post stroke) performed up to six training sessions using a computer-controlled treadmill. Each session had separate progressions focused on initial steps with the non-paretic or paretic limbs in response to anterior or posterior falls. Perturbation magnitudes were altered based on performance and tolerance. Acceptability was determined by adherence, or the number of sessions completed. Practicality was documented by the equipment, space, time, and personnel. Adverse events were documented to reflect safety. In order to determine the potential-efficacy of this training, we compared the proportion of successful recoveries and the highest perturbation magnitude achieved on the first and last sessions.

Results

The training was acceptable, as evident by 12/13 participants completing all 6 sessions. The protocol was practical, requiring one administrator, the treadmill, and a harness. The protocol was safe, as evident by no serious or unanticipated adverse events. The protocol demonstrated promising signs of efficacy. From the first to last sessions, participants had a higher proportion of successful recoveries and progressed to larger disturbances.

Conclusions

Using a computerized treadmill, we developed an approach to fall-recovery training in individuals with chronic stroke that was specific, considered duration and repetition, and incorporated progressive overloading and individualization. We demonstrated that this training was acceptable, practical, safe, and potentially beneficial for high-functioning individuals with chronic stroke.

Trial registration

Retrospectively registered at clinicaltrials.gov (NCT03638089) August 20, 2018.

Analysis of Brain Lesion Impact on Balance and Gait Following Stroke

Falls are a leading cause of serious injury and restricted participation among persons with stroke (PwS). Reactive balance control is essential for fall prevention, however, only a few studies have explored the effects of lesion characteristics (location and extent) on balance control in PwS. We aimed to assess the impact of lesion characteristics on reactive and anticipatory balance capacity, gait, and hemiparetic lower limb function, in PwS. Forty-six subacute PwS were exposed to forward, backward, right and left unannounced horizontal surface translations in six increasing intensities while standing. Fall threshold (i.e., perturbation intensity that results in a fall into the harness system) was measured. In addition, the Berg Balance Scale (BBS), 6 Minute Walk Test (6MWT) and Lower Extremity Fugl-Meyer (LEFM) were measured. Lesion effects were analyzed separately for left and right hemisphere damaged (LHD, RHD) patients, using voxel-based lesion-symptom mapping (VLSM). Our results show that voxel clusters where damage exerted a significant impact on balance, gait and lower-limb function were found in the corticospinal tract (CST), in its passage in the corona radiata and in the posterior limb of the internal capsule. An additional significant impact was found to lesions affecting the putamen and the external capsule (EC). Balance, gait, and hemiparetic lower limb function showed much overlap of the corresponding “significant” voxel clusters. Test scores of RHD and LHD patients were affected largely by damage to homologous regions, with the LHD group showing a wider distribution of “significant” voxels. The study corroborates and extends previous findings by demonstrating that balance control, gait, and lower limb function are all affected mainly by damage to essentially the same brain structures, namely—the CST and adjacent structures in the capsular-putaminal region.

Whole-body and segment angular momentum during 90-degree turns

BACKGROUND

Turning is a frequently performed, asymmetric task of daily living. The asymmetric nature makes turning challenging to perform while maintaining balance.

RESEARCH QUESTION

How do healthy individuals maintain dynamic balance, quantified as whole-body angular momentum, during a 90-degree turn compared to straight-line walking?

METHODS

The kinematics of sixteen healthy individuals were tracked during walking in a straight-line and during left and right 90-degree turns at a comfortable pace. Whole-body and segment angular momenta were calculated and the relative contributions of the legs, arms, pelvis and head/trunk to whole-body angular momentum were evaluated.

RESULTS

Average whole-body angular momentum was different during turning compared to straight-line walking in all planes of motion. The initiation of a turn required generation of whole body angular momentum in all three planes of motion, which was counteracted at the end of the turn by a generation of angular momentum in the opposite direction in the frontal and sagittal planes. Transverse plane momentum was always directed in the turn direction. All segment groups, except for the inside leg, had a greater magnitude of angular momentum during turning compared to straight-line walking. The outside leg and head/trunk segments were the largest contributors to frontal and transverse plane whole-body angular momentum.

SIGNIFICANCE

Understanding how body segments contribute to maintaining balance during a 90-degree turn can be useful for designing rehabilitation paradigms for people who have difficulty turning or impaired balance.

Validity and interrater/intrarater reliability of the Turkish version of the postural assessment scale for stroke patients (PASS-Turk)

Background: There is no Turkish version of the Postural Assessment Scale for Stroke patients (PASS). Objectives: To translate and make the cross-cultural adaptation of the PASS into the Turkish language and evaluate the reliability and validity of the Turkish version (PASS-Turk). Methods: Sixty patients with stroke who had survived the three-week acute period were included in the study. The first researcher applied the scale to the participants twice with 5-day intervals. The second researcher applied the scale once at the same time with the first researcher. The reliability of PASS-Turk and its subsections was evaluated using Cronbach's alpha coefficient. In addition, item-total correlation and test-retest reliability were calculated. The interobserver agreement was assessed using the intraclass correlation coefficient. The construct validity of PASS-Turk was assessed using Pearson's product-moment correlation and principal component analyses. The Berg Balance Scale (BBS) and motor subscale of the Functional Independence Measure (FIM) were used for validity. Results: The Cronbach's alpha coefficients of the PASS-Turk scale were 0.903 for the subsection of "maintaining posture," 0.940 for the subsection of "changing a posture," and 0.953 for the total PASS-Turk scale. The first and second researcher evaluations were perfectly consistent with each other in terms of PASS-Turk total scores (ICC = 0.999, 95% CI: 0.998-0.999, and p < .001). A strong positive correlation was found between PASS-Turk and BBS and the motor subscale of FIM. Conclusion: PASS-Turk is a valid and reliable scale for the evaluation of posture and balance of patients with stroke.

Inter-rater reliability of the Swedish modified version of the Postural Assessment Scale for Stroke Patients (SwePASS) in the acute phase after stroke

Background: Before implementation of the new scale, the Swedish modified version of the Postural Assessment Scale for Stroke Patients (SwePASS), to clinical practice, it is fundamental to analyze its measurement properties.Objective: To examine the inter-rater reliability of the SwePASS in the acute phase after stroke. Methods: Day 3 to day 7 after admission to a stroke unit, 64 persons with stroke were assessed twice, using the SwePASS, by two physiotherapists. Inter-rater reliability was determined using percentage-agreement and the rank-invariant method: relative position, relative concentration, and relative rank variance. Results: The raters showed a percentage agreement of ≥75% in the assessments using the SwePASS. For 9 of the 12 items, the percentage agreement was >80%. For 8 of the 12 items, there was a statistically significant change in position, revealed in relative position values between 0.08 and 0.15. Three items had statistically significant positive relative concentration values between -0.11 and 0.10. Except for a statistically significant negligible relative variance value of 0.01 for the items 1 and 8, there was no relative variance. Conclusions: The SwePASS shows an acceptable inter-rater reliability, albeit with potential for improvement. The reliability can be improved by a consensus how to interpret the scale between the raters prior to implementation in the clinic.

The effect of ankle-foot orthoses on fall/near fall incidence in patients with (sub-)acute stroke: A randomized controlled trial

Falls are commonly reported post-stroke. Ankle-foot orthoses (AFOs) are often provided to improve safety and walking, but the effect of their use in the reduction of falls after stroke is unknown. A randomized controlled trial (RCT) on the effects of AFO-provision after stroke was performed. Effects on clinical scales, 3D-gait kinematics and muscle-activity were previously reported. This paper aims to study the effects of AFO-provision on occurrence and circumstances of falls/near falls. The RCT included unilateral hemiparetic stroke patients. AFOs were provided either early (study week 1) or delayed (study week 9). Both groups were compared in the first eight weeks of the study and diaries were used to register falls/near falls and their circumstances. Follow-up measurements were performed in week 9–52, in which both groups were provided with AFOs. Functional Ambulation Categories and Berg Balance Scale were assessed to determine walking independence and balance, respectively. Last known scores were noted in case of an incident. Thirty-three subjects were included (16 early, 17 delayed). In week 1–8, the early group, who were provided with AFOs, fell significantly more frequently compared with the delayed group, 11 versus 4 times, respectively (Incidence Rate Ratio = 2.9, p = 0.039). Out of the falls recorded in the early group, 63.6% occurred without wearing AFOs. Most of these falls occurred during transfers (36.4%) and standing (27.3%), and notably it were the subjects who did not have independent walking ability. No differences were found for near falls in week 1–8, or for falls/near falls in week 9–52. Six severe consequences (including fractures) were reported from a fall. To conclude, the subjects provided with AFOs early after stroke reported a higher number of falls, compared to the subjects that had not yet been provided with AFOs. However, in the subjects provided with AFOs, 63.6% of the falls occurred whilst without wearing the AFO. Furthermore, the majority of these incidents took place whilst subjects had no independent walking ability. This raises an interesting question of the importance of careful instructions to patients and their relatives, and the influence of potential cognitive impairments on the ability of the subjects to take on these instructions.

Instrumented Version of the Modified Dynamic Gait Index in Patients With Neurologic Disorders

BACKGROUND

Gait instability is common in adults with neurologic disorders and the modified Dynamic Gait Index (mDGI) was recently introduced to assess dynamic balance. However, instrumental assessment is needed to provide quantitative measures.

OBJECTIVE

To develop and validate an instrumented version of the mDGI.

DESIGN

Cross-sectional study.

SETTING

Clinical setting.

PARTICIPANTS

Thirty adults with neurologic disorders (10 with multiple sclerosis, 10 with Parkinson disease, and 10 with stroke) and 20 healthy volunteers.

METHODS

Participants were assessed with the Timed Up and Go test (TUG) and with the mDGI. During the assessment of mDGI, data were collected by a single Inertial Measurement Unit (IMU) positioned on the sternum. Principal component analysis (PCA) was performed on the instrumented data extracting eight PC scores (ImPC) describing dynamic balance. The instrumented overall score (ImDGI) was then calculated as the sum of the mPCs. PCA revealed two components associated with stride features and regularity (ImDGI_Gait_Pattern) and trunk movements (ImDGI_Trunk_Sway). Spearman coefficients were calculated between mDGI and ImDGI, whereas Mann-Whitney (U) and Kruskal-Wallis (H) tests assessed differences between groups and neurologic conditions.

MAIN OUTCOME MEASUREMENTS

ImDGI.

RESULTS

ImDGI did not show ceiling effects, and good correlations were found between ImDGI and mDGI (r = .84), and TUG (r = .84) for people with neurologic disorders (P < .001). Significant differences among pathologies (H test₍₂₎ =12.5, P = .002) and between healthy participants and adults with neurologic disorders (U test = 47.0, P = .001) were found. ImDGI_Trunk_Sway discriminated between people using or not using walking aids and among the three pathologies (H₍₂₎ = 10.0, P = .007).

CONCLUSIONS

The ImDGI test seems to provide valid measures to objectively assess dynamic balance in neurologic conditions and possibly quantify balance deficits also in adults with neurologic disorders.

Dynamic balance and instrumented gait variables are independent predictors of falls following stroke

BACKGROUND

Falls are common following stroke and are frequently related to deficits in balance and mobility. This study aimed to investigate the predictive strength of gait and balance variables for evaluating post-stroke falls risk over 12 months following rehabilitation discharge.

METHODS

A prospective cohort study was undertaken in inpatient rehabilitation centres based in Australia and Singapore. A consecutive sample of 81 individuals (mean age 63 years; median 24 days post stroke) were assessed within one week prior to discharge. In addition to comfortable gait speed over six metres (6mWT), a depth-sensing camera (Kinect) was used to obtain fast-paced gait speed, stride length, cadence, step width, step length asymmetry, gait speed variability, and mediolateral and vertical pelvic displacement. Balance variables were the step test, timed up and go (TUG), dual-task TUG, and Wii Balance Board-derived centre of pressure velocity during static standing. Falls data were collected using monthly calendars.

RESULTS

Over 12 months, 28% of individuals fell at least once. The faller group had increased TUG time and reduced stride length, gait speed variability, mediolateral and vertical pelvic displacement, and step test scores (P < 0.001-0.048). Significant predictors, when adjusted for country, prior falls and assistance (i.e., physical assistance and/or gait aid use) were stride length, step length asymmetry, mediolateral pelvic displacement, step test and TUG scores (P < 0.040; IQR-odds ratio(OR) = 1.37-7.85). With comfortable gait speed as an additional covariate, to determine the additive benefit over standard clinical assessment, only mediolateral pelvic displacement, TUG and step test scores remained significant (P = 0.001-0.018; IQR-OR = 5.28-10.29).

CONCLUSIONS

Reduced displacement of the pelvis in the mediolateral direction during walking was the strongest predictor of post-stroke falls compared with other gait variables. Dynamic balance measures, such as the TUG and step test, may better predict falls than gait speed or static balance measures.

Functional measurement post-stroke via mobile application and body-worn sensor technology

BACKGROUND

Long-term management of individuals post-stroke is essential due to the resultant chronic disability and risk for recurrent stroke. Mobile health technology shows increasing promise to provide cost-effective monitoring and support systems for the patient, caregiver, and healthcare team. Ideally, such systems will include stroke management adherence support, mechanisms to link patients and caregivers to resources, and secure longitudinal data collection with archive that are employed to optimize recovery. However, healthcare providers and computer science application developers must first collaborate to identify meaningful measures and develop methods to reliably gather such data remotely via mobile systems.

METHODS

mStroke is a mobile health system composed of two sensors and a mobile application designed to support optimal recovery for stroke survivors. Using the World Health Organization's International Classification of Functioning, Disability and Health model (ICF model), the authors identified 4 measures that are commonly used in the clinic and developed the mobile application features to support remote data collection: National Institutes of Health Stroke Scale (NIHSS) items 5 and 6 (Motor Arm and Leg function), Functional Reach Test (FRT), and 10 Meter Walk Test (10MWT). At a local inpatient rehabilitation facility, each measure was executed with 35 stroke survivors through simultaneous scoring by the mStroke system and standardized clinical assessment. Correlation coefficients were calculated for clinician versus mStroke system scoring.

RESULTS

All four clinical measures significantly correlated with mStroke system app scoring: NIHSS Motor Arm-0.839, P<0.001; NIHSS Motor Leg-0.736, P<0.001; FRT-0.630, P<0.01; 10MWT-0.994, P<0.001.

CONCLUSIONS

Results should be approached with caution as significant data skew was present for NIHSS Motor Arm and Motor Leg tests and the FRT results are not strong enough for broad translation. However, positive findings were demonstrated that support further investment in development, refinement, and testing of mobile health systems to provide clinically meaningful remote measurement via mobile technology. The ICF model was a helpful framework for guiding clinician and application developer collaboration and identifying meaningful features for app development.

Mediolateral footpath stabilization during walking in people following stroke

Community dwelling stroke survivors most often fall while walking. Understanding how post-stroke individuals control mediolateral footpath during walking may help elucidate the mechanisms that contribute to walking instability. By applying the Uncontrolled Manifold (UCM) approach, we investigated (1) how post-stroke individuals coordinate lower-extremity joint motions to stabilize mediolateral footpath of the swing leg, and (2) how the inter-joint coordination in footpath stabilization correlates to their walking stability. Nine stroke subjects and nine healthy controls walked on a treadmill at four different speeds. UCM analysis partitions the variance of kinematic configurations across gait cycles into "good variance" (i.e., the variance component leading to a consistent footpath) or "bad variance" (i.e., the variance component leading to an inconsistent footpath). We found that both groups had a significantly greater "good" than "bad" variance (p<0.05) for most of the swing phase, suggesting that mediolateral footpath is an important variable stabilized by the central nervous system during walking. Stroke subjects had significantly greater relative variance difference (ΔV) (i.e. normalized difference between "good" and "bad" variance) (p<0.05), indicating a stronger kinematic synergy in footpath stabilization, than the controls. In addition, the kinematic synergy in mediolateral footpath stabilization is strongest during mid-swing but weakest during late swing in healthy gait. However, this phase-dependent strategy is preserved for mid-swing but not for late swing in stroke gait. Moreover, stroke and healthy subjects demonstrated different relationships between UCM and walking stability measures. A stronger kinematic synergy in healthy gait is associated with better walking stability whereas having more "good variance" or stronger kinematic synergy in stroke gait is associated with less walking stability. The current findings suggest that walking with too much "good variance" in people following stroke, despite no effect on the footpath, may adversely affect their walking stability to some extent.

Using the Brief-BESTest paired with a novel algorithm to provide targeted balance interventions for people with subacute stroke: a feasibility study

BACKGROUND

Balance is a common mobility limitation following stroke, but determination of the most effective balance-related plan of care can be difficult due to multiple balance impairments that vary between individuals. The Brief-BESTest is a validated outcome measure for balance based on six systems of postural control. It may also be a useful tool to guide clinicians in their balance plan of care design.

OBJECTIVE

The objective of this study was to determine the feasibility of a quantitative balance plan of care for patients with subacute stroke, using a novel algorithm that utilizes the scoring design of the Brief-BESTest. The authors hypothesized that this plan of care could create targeted balance interventions among this population.

METHODS

Eligible patients with subacute stroke at an inpatient rehab facility completed the Brief-BESTest within 1 week of admission. The subjects participated in specific interventions based on test section scores during their rehab stay.

RESULTS

Five subjects completed testing and participated in targeted balance interventions, addressing three to five systems of postural control. Subjects demonstrated improved Brief-BESTest overall scores by 2, 1, 7, 4, and 6 points from admission to discharge. Improvements in section scores were primarily seen in the systems of postural control identified by the algorithm. All subjects improved in Functional Independence Measure (FIM™)³⁰ scores for locomotion (walking and stairs) by 5, 6, 7, 6, and 9 points, respectively. All subjects were discharged to the community.

CONCLUSION

Our observational study found this method of assessment and intervention to be feasible in the subacute stroke population and was associated with improved balance scores and improved functional mobility. Further study is warranted to determine effectiveness and efficiency.

Threshold-based fall detection using a hybrid of tri-axial accelerometer and gyroscope

OBJECTIVE

Falling is an important health maintenance issue for the elderly and people with movement disorders, strokes and multiple sclerosis. With the development of light, low-cost wearable technology, inertia-based fall detection has gained much attention. However, some large movements, such as jumping and postural changes, are frequently confounded with falls. For example, commonly used fall detection methods based on acceleration amplitude produce a large number of false alerts unless they are combined with post-fall posture identification. In this paper, we propose two new inertial parameters to improve the selectivity of threshold-based fall detection methods, and evaluate strategies to distinguish falls from other activities of daily life (ADLs).

APPROACH

We define two new inertial parameters, acceleration cubic-product-root magnitude (ACM) and angular velocity cubic-product-root magnitude (AVCM). Along with acceleration magnitude (AM), we test threshold-based fall detection methods based on single parameters and combinations. We collected inertial data on four types of simulated falls and eight types of ADLs from a study with 15 participants wearing a chest-mounted sensor with accelerometer and gyroscope. Two public datasets, UMAFall and Cognent Labs, were also included to evaluate fall detection methods.

MAIN RESULTS

We chose the detection threshold with 99% sensitivity and the best possible specificity. The hybrid of AM, ACM and AVCM method had a lower rate of misclassification than single-parameter methods. Leave-one-out cross-validation shows that the hybrid fall detection method can achieve both high specificity and high sensitivity.

SIGNIFICANCE

Using multiple inertial parameters improves the specificity of fall detection.

Identifying trippers and non-trippers based on knee kinematics during obstacle-free walking

Trips are a major cause of falls. Sagittal-plane kinematics affect clearance between the foot and obstacles, however, it is unclear which kinematic measures during obstacle-free walking are associated with avoiding a trip when encountering an obstacle. The purpose of this study was to determine kinematic factors during obstacle-free walking that are related to obstacle avoidance ability. It was expected that successful obstacle avoidance would be associated with greater peak flexion/dorsiflexion and range of motion (ROM), and differences in timing of peak flexion/dorsiflexion during swing of obstacle-free walking for the hip, knee and ankle. Three-dimensional kinematics were recorded as 35 participants (young adults age 18-45 (N = 10), older adults age 65+ without a history of falls (N = 10), older adults age 65+ who had fallen in the last six months (N = 10), and individuals who had experienced a stroke more than six months earlier (N = 5)) walked on a treadmill, under obstacle-free walking conditions with kinematic features calculated for each stride. A separate obstacle avoidance task identified trippers (multiple obstacle contact) and non-trippers. Linear discriminant analysis with sequential feature selection classified trippers and non-trippers based on kinematics during obstacle-free walking. Differences in classification performance and selected features (knee ROM and timing of peak knee flexion during swing) were evaluated between trippers and non-trippers. Non-trippers had greater knee ROM (P = .001). There was no significant difference in classification performance (P = .193). Individuals with reduced knee ROM during obstacle-free walking may have greater difficulty avoiding obstacles.

Effects of Stochastic Resonance Whole-Body Vibration in Individuals with Unilateral Brain Lesion: A Single-Blind Randomized Controlled Trial: Whole-Body Vibration and Neuromuscular Function

Introduction

Stochastic resonance whole-body vibration (SR-WBV) devices are promising sensorimotor interventions to address muscle weakness and to improve balance and mobility particularly in the elderly. However, it remains inconclusive whether individuals with stroke or traumatic brain injury (TBI) can profit from this method. The aim of this prospective single-blind randomized controlled trial was to investigate the effects of SR-WBV on muscle strength as well as gait and balance performance in this population.

Methods

Forty-eight individuals with stroke or TBI were randomly allocated to an experimental and a sham group. Participants were exposed daily to 5 consecutives 1-minute SR-WBV sessions, whereas the experimental group trained in a standing position with 5 Hz and the sham group in a seated position with 1 Hz. Isometric muscle strength properties of the paretic knee extensor muscles as well as balance and gait performance were measured at baseline, after the first session and after two weeks of SR-WBV.

Results

Both groups showed short- and long-term effects in gait performance. However, no between-group effects could be found at the three measurement points.

Discussion

Complementary SR-WBV showed no beneficial effects immediately after the intervention and after two weeks of conventional rehabilitation therapy. Future research is needed to identify the potential efficacy of SR-WBV in individuals with stroke and TBI using shorter and less exhausting test procedures and a generally prolonged intervention time.

Home-based balance training using Wii Fit™: a pilot randomised controlled trial with mobile older stroke survivors

Background

Several studies have reported that using the Wii™ Balance Board can provide added value regarding balance (re-)training in neurological diseases. However, for the large group of mobile older stroke survivors, there is no evidence regarding the feasibility of an unsupervised Wii™ Balance Board training in the home setting. The aim of this study was to investigate the feasibility of a home-based Wii™ balance training for these patients and to identify methodological challenges for randomised controlled trials in the future.

Methods

We conducted a pilot randomised controlled trial with two intervention arms in participants' homes. Mobile stroke survivors (aged 60 years or above; 12 weeks after discharge from hospital) received a 6-week (once per week) supervised balance training at the study centre, followed by a 6-week (three times per week) unsupervised balance training at home. We used the Nintendo Wii™ Balance Board for one intervention arm and conventional balance exercises for the other intervention arm. Feasibility was assessed by recruiting rates, appropriateness of assessments regarding sensitivity to changes and acceptance of the intervention by the participants.

Results

In two German hospital stroke units, 349 stroke survivors were screened over a period of 6 months, 91 were eligible and 52 were interested. Twelve weeks after discharge, 14 participants agreed and 11 completed the intervention (7 men and 4 women, mean age 74 years). The Berg Balance Scale and Dynamic Gait Index showed ceiling effects already at baseline measure. The participants in both intervention arms evaluated the unsupervised training positively and feasible for self-application. No falls or injuries occurred over the intervention period, while the required scope of the exercises could largely be achieved.

Conclusions

In this pilot study, the recruitment of participants and the chosen assessments were not satisfactory due to selection bias and corresponding ceiling effects. However, the two home-based balance interventions proved feasible for mobile older stroke survivors with low functional limitations.

Trial registration

ClinicalTrials.gov, NCT02251470. Registered 29 September 2014.