Predicting Recovery of Independent Walking After Stroke: A Systematic Review.

ABSTRACT: Patients recovering from a stroke experience reduced participation, especially when they are limited in daily activities involving walking. Understanding the recovery of independent walking, can be used by clinicians in the decision-making process during rehabilitation, resulting in more personalized stroke rehabilitation. Therefore, it is necessary to gain insight in predicting the recovery of independent walking in patients after stroke. This systematic review provided an overview of current evidence about prognostic models and its performance to predict recovery of independent walking after stroke. Therefore, MEDLINE, CINAHL, and Embase were searched for all relevant studies in English and Dutch. Descriptive statistics, study methods, and model performance were extracted and divided into two categories: subacute phase and chronic phase. This resulted in 16 articles that fulfilled all the search criteria, which included 30 prognostic models. Six prognostic models showed an excellent performance (area under the curve value and/or overall accuracy ≥0.90). The model of Smith et al. (2017) showed highest overall accuracy (100%) in predicting independent walking in the subacute phase after stroke ( Neurorehabil Neural Repair 2017;31(10-11):955-64.). Recovery of independent walking can be predicted in the subacute and chronic phase after stroke. However, proper external validation and the applicability in clinical practice of identified prognostic models are still lacking.

Reliability of IMU-Based Gait Assessment in Clinical Stroke Rehabilitation.

BACKGROUND: Gait is often impaired in people after stroke, restricting personal independence and affecting quality of life. During stroke rehabilitation, walking capacity is conventionally assessed by measuring walking distance and speed. Gait features, such as asymmetry and variability, are not routinely determined, but may provide more specific insights into the patient's walking capacity. Inertial measurement units offer a feasible and promising tool to determine these gait features. OBJECTIVE: We examined the test-retest reliability of inertial measurement units-based gait features measured in a two-minute walking assessment in people after stroke and while in clinical rehabilitation. METHOD: Thirty-one people after stroke performed two assessments with a test-retest interval of 24 h. Each assessment consisted of a two-minute walking test on a 14-m walking path. Participants were equipped with three inertial measurement units, placed at both feet and at the low back. In total, 166 gait features were calculated for each assessment, consisting of spatio-temporal (56), frequency (26), complexity (63), and asymmetry (14) features. The reliability was determined using the intraclass correlation coefficient. Additionally, the minimal detectable change and the relative minimal detectable change were computed. RESULTS: Overall, 107 gait features had good-excellent reliability, consisting of 50 spatio-temporal, 8 frequency, 36 complexity, and 13 symmetry features. The relative minimal detectable change of these features ranged between 0.5 and 1.5 standard deviations. CONCLUSION: Gait can reliably be assessed in people after stroke in clinical stroke rehabilitation using three inertial measurement units.

To What Extent is Walking Ability Associated with Participation in People after Stroke?

OBJECTIVES: This study aims to 1) identify the relation between walking ability and participation after stroke and 2) explore whether change in walking ability is associated with change in participation over time in community living-people after stroke. MATERIALS AND METHODS: Fifty-two people after stroke were assessed at baseline and after a 6-week gait training intervention. People were included between two weeks and six months after stroke. The Utrecht Scale for Evaluation of Rehabilitation-Participation was used to measure participation. Assessment of walking ability included the six-minute walking test for walking endurance, Timed-up & Go test for functional mobility, Mini Balance Evaluation Systems Test for dynamic balance, and total duration of walking activity per day to measure walking activity. RESULTS: At baseline, six-minute walking test, Timed-up & Go test, and Mini Balance Evaluation Systems Test were univariately associated with participation (P < 0.001). Backward multiple regression analysis showed that the Mini Balance Evaluation Systems Test independently explained 55.7% of the variance in participation at baseline. Over time, only change in the six-minute walking test was positively associated with change in participation (R2 = 0.087, P = 0.040). CONCLUSIONS: Cross-sectional associations showed that walking ability, and especially dynamic balance, contributes to participation after stroke. Dynamic balance, as underlying variable for walking, was an important independently related factor to participation after stroke which needs attention during rehabilitation. Longitudinally, improvement in walking endurance was significantly associated with improvement in participation, which indicates the relevance of training walking endurance to improve participation after stroke.

Effect of Virtual Reality Gait Training on Participation in Survivors of Subacute Stroke: A Randomized Controlled Trial.

OBJECTIVE: After stroke, people experience difficulties with walking that lead to restrictions in participation in daily life. The purpose of this study was to examine the effect of virtual reality gait training (VRT) compared to non-virtual reality gait training (non-VRT) on participation in community-living people after stroke. METHODS: In this assessor-blinded, randomized controlled trial with 2 parallel groups, people were included between 2 weeks and 6 months after stroke and randomly assigned to the VRT group or non-VRT group. Participants assigned to the VRT group received training on the Gait Real-time Analysis Interactive Lab (GRAIL), and participants assigned to the non-VRT group received treadmill training and functional gait exercises without virtual reality. Both training interventions consisted of 12 30-minute sessions during 6 weeks. The primary outcome was participation measured with the restrictions subscale of the Utrecht Scale for Evaluation of Rehabilitation-Participation (USER-P) 3 months postintervention. Secondary outcomes included subjective physical functioning, functional mobility, walking ability, dynamic balance, walking activity, fatigue, anxiety and depression, falls efficacy, and quality of life. RESULTS: Twenty-eight participants were randomly assigned to the VRT group and 27 to the non-VRT group, of whom 25 and 22 attended 75% or more of the training sessions, respectively. No significant differences between the groups were found over time for the USER-P restrictions subscale (1.23; 95% CI = -0.76 to 3.23) or secondary outcome measures. Patients' experiences with VRT were positive, and no serious adverse events were related to the interventions. CONCLUSIONS: The effect of VRT was not statistically different from non-VRT in improving participation in community-living people after stroke. IMPACT: Although outcomes were not statistically different, treadmill-based VRT was a safe and well-tolerated intervention that was positively rated by people after stroke. VR training might, therefore, be a valuable addition to stroke rehabilitation. LAY SUMMARY: VRT is feasible and was positively experienced by people after stroke. However, VRT was not more effective than non-VRT for improving walking ability and participation after stroke.

Reproducibility of Different Methodologies to Calculate Oxygen Consumption and Oxygen Cost During Walking in Chronic Stroke Survivors.

OBJECTIVE: The most common methods to calculate energy costs are based on measured oxygen uptake during walking a standardized distance or time. Unfortunately, it is unclear which method is most reliable to determine energy cost of walking in stroke survivors. The objective of this study was to evaluate the 3 most commonly used methods for calculating oxygen consumption and -cost by assessing test-retest reliability and measurement error in community dwelling chronic stroke survivors during a 6 Minute Walk Test. METHODS: In this secondary analysis of a longitudinal study, reproducibility of the outcome of walking distance, walking speed, oxygen consumption and oxygen cost from 3 methods (Kendall's tau, assumed steady-state and total walking time oxygen consumption) were determined using Intraclass Correlation Coefficient, Standard Error of Measurement and Smallest Detectable Change. RESULTS: 20 from the 31 participants successfully performed the 6 minute walk test-retest within a timeframe of 1 month. Within the 2 tests the reproducibility of walking distance and walking speed was high. The 3 methods to determine reproducibility for oxygen cost and oxygen consumption were considered good (Kendall's tau), good (assumed steady-state) and excellent (total walking time). CONCLUSIONS: The method using oxygen consumption and -cost over the total walking time resulted in the highest reproducibility considering the Intraclass Correlation Coefficient, its 95% Confidence Interval, and smaller absolute differences.

Walking activity and its determinants in free-living ambulatory people in a chronic phase after stroke: a cross-sectional study.

Background: Free-living walking activity and its contributing factors in ambulatory people with stroke is poorly investigated.Objective: Evaluating free-living walking activity and identifying factors associated with free-living walking activity.Methods: In this cross-sectional study, participants wore an accelerometer to measure their level of walking activity. They also completed the Berg Balance Scale (BBS) and the Timed Up and Go test for functional balance, the Falls Efficacy Scale, the 10-Metre Walk Test and the Geriatric Depression Scale to investigate the relation between the performance tests and walking activity.Results: The 38 analyzed participants were on average 62 (±11.4) years old and 66 (IQR 64.8) months post stroke. They took an average of 3048.3 ± 1983.1 steps, had 123.3 ± 61.3 walking bouts a day and walked for 32.5 ± 18.2 min a day. Their average speed was 90.3 ± 13.8 steps a minute. The multivariate linear analysis showed that the BBS was the only determinant that was significantly related to all outcomes, except walking bouts.Conclusion: Free-living walking activity levels in ambulatory people with chronic stroke are low. The BBS is an independent significant predictor of free-living walking activity.Implications for rehabilitationFree-living walking activity can be expressed in different outcomes measured by accelerometry.Free-living walking activity levels in ambulatory people with chronic stroke are low, therefore support to sustain walking in the own environment should be part of the rehabilitation program after stroke.Balance is an important related factor to free-living walking activity which needs attention during rehabilitation after stroke.

Real-time feedback to reduce low-back load in lifting and lowering.

Low-back pain (LBP) is a common health problem. Literature indicates an exposure-response relation between work-related lifting and LBP. Therefore, this study investigated effects of three kinds of real-time feedback on low-back load, quantified as lumbar moments, during lifting. We recruited 97 healthy male and female participants without a recent history of LBP and without prior biomechanical knowledge on lifting. Participants were assigned to groups based on the time of enrollment, filling the four groups in the following order: moment feedback, trunk inclination angle feedback, lumbar flexion feedback, and a control group not receiving feedback. Feedback was given by a sound when a threshold level of the input variable was exceeded. Participants were unaware of the input variable for the feedback, but were instructed to try to avoid the audio feedback by changing their lifting strategy. The groups with feedback were able to reduce the audio feedback and thus changed the input variable towards a more desired level. Lumbar moments significantly decreased over trials in the inclination and moment feedback groups, remained similar in the lumbar flexion group and increased in the control group. Between group comparisons revealed that low-back load was significantly lower in the moment and inclination groups compared to the control group. Additionally, moments were lower in the inclination group than in the lumbar flexion group. Real-time feedback on moments or trunk inclination is a promising tool to reduce low-back load during lifting and lowering.

Does a Perturbation-Based Gait Intervention Enhance Gait Stability in Fall-Prone Stroke Survivors? A Pilot Study.

A recent review indicated that perturbation-based training (PBT) interventions are effective in reducing falls in older adults and patients with Parkinson's disease. It is unknown whether this type of intervention is effective in stroke survivors. We determined whether PBT can enhance gait stability in stroke survivors. A total of 10 chronic stroke survivors who experienced falls in the past 6 months participated in the PBT. Participants performed 10 training sessions over a 6-week period. The gait training protocol was progressive, and each training contained unexpected gait perturbations and expected gait perturbations. Evaluation of gait stability was performed by determining steady-state gait characteristics and daily-life gait characteristics. We previously developed fall prediction models for both gait assessment methods. We evaluated whether predicted fall risk was reduced after PBT according to both models. Steady-state gait characteristics significantly improved, and consequently, predicted fall risk was reduced after the PBT. However, daily-life gait characteristics did not change, and thus, predicted fall risk based on daily-life gait remained unchanged after the PBT. A PBT resulted in more stable gait on a treadmill and thus lower predicted fall risk. However, the more stable gait on the treadmill did not transfer to a more stable gait in daily life.

Virtual obstacle crossing: Reliability and differences in stroke survivors who prospectively experienced falls or no falls.

INTRODUCTION: Stroke survivors often fall during walking. To reduce fall risk, gait testing and training with avoidance of virtual obstacles is gaining popularity. However, it is unknown whether and how virtual obstacle crossing is associated with fall risk. AIM: The present study assessed whether obstacle crossing characteristics are reliable and assessed differences in stroke survivors who prospectively experienced falls or no falls. METHOD: We recruited twenty-nine community dwelling chronic stroke survivors. Participants crossed five virtual obstacles with increasing lengths. After a break, the test was repeated to assess test-retest reliability. For each obstacle length and trial, we determined; success rate, leading limb preference, pre and post obstacle distance, margins of stability, toe clearance, and crossing step length and speed. Subsequently, fall incidence was monitored using a fall calendar and monthly phone calls over a six-month period. RESULTS: Test-retest reliability was poor, but improved with increasing obstacle-length. Twelve participants reported at least one fall. No association of fall incidence with any of the obstacle crossing characteristics was found. DISCUSSION: Given the absence of height of the virtual obstacles, obstacle avoidance may have been relatively easy, allowing participants to cross obstacles in multiple ways, increasing variability of crossing characteristics and reducing the association with fall risk. CONCLUSION: These finding cast some doubt on current protocols for testing and training of obstacle avoidance in stroke rehabilitation.

Do clinical assessments, steady-state or daily-life gait characteristics predict falls in ambulatory chronic stroke survivors?

OBJECTIVE: This exploratory study investigated to what extent gait characteristics and clinical physical therapy assessments predict falls in chronic stroke survivors. DESIGN: Prospective study. SUBJECTS: Chronic fall-prone and non-fall-prone stroke survivors. METHODS: Steady-state gait characteristics were collected from 40 participants while walking on a treadmill with motion capture of spatio-temporal, variability, and stability measures. An accelerometer was used to collect daily-life gait characteristics during 7 days. Six physical and psychological assessments were administered. Fall events were determined using a "fall calendar" and monthly phone calls over a 6-month period. After data reduction through principal component analysis, the predictive capacity of each method was determined by logistic regression. RESULTS: Thirty-eight percent of the participants were classified as fallers. Laboratory-based and daily-life gait characteristics predicted falls acceptably well, with an area under the curve of, 0.73 and 0.72, respectively, while fall predictions from clinical assessments were limited (0.64). CONCLUSION: Independent of the type of gait assessment, qualitative gait characteristics are better fall predictors than clinical assessments. Clinicians should therefore consider gait analyses as an alternative for identifying fall-prone stroke survivors.

Responses to gait perturbations in stroke survivors who prospectively experienced falls or no falls.

BACKGROUND: Steady-state gait characteristics appear promising as predictors of falls in stroke survivors. However, assessing how stroke survivors respond to actual gait perturbations may result in better fall predictions. We hypothesize that stroke survivors who fall have a diminished ability to adequately adjust gait characteristics after gait is perturbed. This study explored whether gait characteristics of perturbed gait differ between fallers and non fallers. METHOD: Chronic stroke survivors were recruited by clinical therapy practices. Prospective falls were monitored over a six months follow up period. We used the Gait Real-time Analysis Interactive Lab (GRAIL, Motekforce Link B.V., Amsterdam) to assess gait. First we assessed gait characteristics during steady-state gait and second we examined gait responses after six types of gait perturbations. We assessed base of support gait characteristics and margins of stability in the forward and medio-lateral direction. FINDINGS: Thirty eight stroke survivors complete our gait protocol. Fifteen stroke survivors experienced falls. All six gait perturbations resulted in a significant gait deviation. Forward stability was reduced in the fall group during the second step after a ipsilateral perturbation. INTERPRETATION: Although stability was different between groups during a ipsilateral perturbation, it was caused by a secondary strategy to keep up with the belt speed, therefore, contrary to our hypothesis fallers group of stroke survivors have a preserved ability to cope with external gait perturbations as compared to non fallers. Yet, our sample size was limited and thereby, perhaps minor group differences were not revealed in the present study.

Characteristics of daily life gait in fall and non fall-prone stroke survivors and controls.

BACKGROUND: Falls in stroke survivors can lead to serious injuries and medical costs. Fall risk in older adults can be predicted based on gait characteristics measured in daily life. Given the different gait patterns that stroke survivors exhibit it is unclear whether a similar fall-prediction model could be used in this group. Therefore the main purpose of this study was to examine whether fall-prediction models that have been used in older adults can also be used in a population of stroke survivors, or if modifications are needed, either in the cut-off values of such models, or in the gait characteristics of interest. METHODS: This study investigated gait characteristics by assessing accelerations of the lower back measured during seven consecutive days in 31 non fall-prone stroke survivors, 25 fall-prone stroke survivors, 20 neurologically intact fall-prone older adults and 30 non fall-prone older adults. We created a binary logistic regression model to assess the ability of predicting falls for each gait characteristic. We included health status and the interaction between health status (stroke survivors versus older adults) and gait characteristic in the model. RESULTS: We found four significant interactions between gait characteristics and health status. Furthermore we found another four gait characteristics that had similar predictive capacity in both stroke survivors and older adults. CONCLUSION: The interactions between gait characteristics and health status indicate that gait characteristics are differently associated with fall history between stroke survivors and older adults. Thus specific models are needed to predict fall risk in stroke survivors.

Effect of arm swing strategy on local dynamic stability of human gait.

INTRODUCTION: Falling causes long term disability and can even lead to death. Most falls occur during gait. Therefore improving gait stability might be beneficial for people at risk of falling. Recently arm swing has been shown to influence gait stability. However at present it remains unknown which mode of arm swing creates the most stable gait. AIM: To examine how different modes of arm swing affect gait stability. METHOD: Ten healthy young male subjects volunteered for this study. All subjects walked with four different arm swing instructions at seven different gait speeds. The Xsens motion capture suit was used to capture gait kinematics. Basic gait parameters, variability and stability measures were calculated. RESULTS: We found an increased stability in the medio-lateral direction with excessive arm swing in comparison to normal arm swing at all gait speeds. Moreover, excessive arm swing increased stability in the anterior-posterior and vertical direction at low gait speeds. Ipsilateral and inphase arm swing did not differ compared to a normal arm swing. DISCUSSION: Excessive arm swing is a promising gait manipulation to improve local dynamic stability. For excessive arm swing in the ML direction there appears to be converging evidence. The effect of excessive arm swing on more clinically relevant groups like the more fall prone elderly or stroke survivors is worth further investigating. CONCLUSION: Excessive arm swing significantly increases local dynamic stability of human gait.

Clinimetric properties of a novel feedback device for assessing gait parameters in stroke survivors.

INTRODUCTION: Community-dwelling stroke survivors tend to become less physically active over time. There is no 'gold standard' to measure walking activity in this population. Assessment of walking activity generally involves subjective or observer-rated instruments. Objective measuring with an activity monitor, however, gives more insight into actual walking activity. Although several activity monitors have been used in stroke patients, none of these include feedback about the actual walking activity. FESTA (FEedback to Stimulate Activity) determines number of steps, number of walking bouts, covered distance and ambulatory activity profiles over time and also provides feedback about the walking activity to the user and the therapist. AIM: To examine the criterion validity and test-retest-reliability of the FESTA as a measure of walking activity in patients with chronic stroke. To target the properties of the measurement device itself and thus exclude effects of behavioral variability as much as possible evaluation was performed in standardized activities. METHODS: Community-dwelling individuals with chronic stroke were tested twice with a test-retest interval varying from two days to two weeks. They performed a six-minute walk test and a standardized treadmill test at different speeds on both testing days. Walking activity was expressed in gait parameters: steps, mean-step-length and walking distance. Output data of the FESTA on the treadmill was compared with video analysis as the criterion measurement. Intraclass Correlations Coefficients (ICCs) and Mean Relative Root Squared Error (MRRSE) were calculated. RESULTS: Thirty-three patients were tested to determine criterion validity, 27 patients of this group were tested twice for test-retest reliability. ICC values for validity and reliability were high, ranging from .841 to .972. CONCLUSION: This study demonstrated good criterion validity and test-retest-reliability of FESTA for measuring specific gait parameters in chronic stroke patients. FESTA is a valid and reliable tool for capturing walking activity measurements in stroke, and has applicability to both clinical practice and research.