Dimensionality and Item-Difficulty Hierarchy of the Lower Extremity Fugl-Meyer Assessment in Individuals With Subacute and Chronic Stroke.

OBJECTIVE: To investigate the dimensionality and item-difficulty hierarchy of the Fugl-Meyer Assessment of the lower extremity (FMA-LE). DESIGN: Secondary analyses of data pooled from 4 existing datasets: a phase III randomized controlled trial investigating the effectiveness of body weight support and a treadmill for rehabilitation of walking poststroke, and 3 cross-sectional studies investigating the link between impaired motor performance poststroke and walking. SETTING: University research centers and rehabilitation centers. PARTICIPANTS: A pooled sample of individuals with a stroke (N=535, men=313; mean age ± SD, 61.91±12.42y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Confirmatory factor analyses (CFA) and Rasch residual principal component analysis (PCA) investigated the dimensionality of the FMA-LE. The Rasch analysis rating scale model investigated item-difficulty hierarchy of the FMA-LE. RESULTS: The CFA showed adequate fit of a 3-factor model, with 2 out of 3 indices (CFA=.95; Tucker-Lewis Index=.94; root mean square error of approximation=.124) showing good model fit. Rasch PCA showed that removal of the reflex and coordination items explained 90.8% of variance in the data, suggesting that the abnormal synergy items contributed to the measurement of a unidimensional construct. However, rating scale model results revealed deviations in the item-difficulty hierarchy of the unidimensional abnormal synergy items from the originally proposed stepwise sequence of motor recovery. CONCLUSIONS: Our findings suggest that the FMA-LE might represent a multidimensional construct, challenging the use of a total score of the FMA-LE to predict lower extremity motor recovery. Removal of the misfit items resulted in creation of a unidimensional scale composed of the abnormal synergy items. However, this unidimensional scale deviates from the originally proposed hierarchical ordering.

Post-stroke gait training practices in a low resource setting: a cross-sectional survey among Indian physiotherapists.

BACKGROUND: Independent mobility is the most important determinant of quality of life after stroke and it is vital that training aimed at restoration of gait is based on contemporary evidence. Despite several practice guidelines for gait rehabilitation after stroke existing globally, their feasibility of application in low-resource settings is often questionable. OBJECTIVE: To investigate the current practices in gait training among Indian physiotherapists involved in the rehabilitation of stroke survivors. METHODS: A questionnaire on the various aspects of gait training was developed and the content was validated by experts. The survey was made available online and distributed among Indian physiotherapists working in the field of stroke rehabilitation, using snowball sampling. Frequency distribution was used to summarize responses to each component of the questionnaire. RESULTS: Responses were obtained from 250 practicing physiotherapists. The majority of the respondents (55%) reported that they initiate gait training within seven days after stroke. Gait training sessions ranged from 15-30 minutes (55%), once every day (44%), and the majority (89%) reported use of subjective outcome measures to evaluate gait. Although most respondents agreed on the use of assistive aids, 24% indicated that their use may deter gait, rather than improve it. Nearly 86% of the respondents reported that they do not follow standard guidelines pertaining to gait rehabilitation for stroke survivors. CONCLUSION: The findings of the study point toward a lack of evidence-based practice among Indian physiotherapists while training gait after stroke. This implied the urgent need for development and implementation of country specific guidelines for stroke rehabilitation.

Gait training interventions for patients with stroke in India: A systematic review.

BACKGROUND: Gait is considered to be the most important determinant of functional independence in activities of daily living. The challenges faced by stroke survivors in India differ from the western population due to economic, cultural, and geographical factors and this, in turn, may influence the choice of intervention. Hence, there is a need to understand the current gait training trends for stroke survivors in low resource settings like India. RESEARCH QUESTION: To systematically review the literature on interventional strategies for improving gait among stroke survivors in India. METHODS: Six databases were searched to identify RCTs delivering gait training to stroke survivors having some gait deficits in terms of speed or any other kinematic parameters. Studies of the English language from India were included. Two independent reviewers screened, extracted data, and assessed the study quality. A descriptive synthesis was undertaken and the data was summarized. RESULTS: Of 2112 potentially relevant articles, 12 studies with a total of 412 participants were included after title, abstract and full-text screening. Studies tested the efficacy of interventions such as mirror therapy, motor imagery, transcutaneous electrical nerve stimulation, strengthening, and task-based training. The outcome measures were kinematic gait-analysis, gait velocity, Functional Ambulation Categories, Timed Up and Go, Fugl-Meyer Assessment. From the results of this review, active task-based gait training and strengthening along with motor priming seems to be the most tested interventions. Future studies may need to design interventions targeting both impairment and function to bring about maximum improvement in gait after stroke. SIGNIFICANCE: Reviews addressing gait practices in developing countries for people with stroke are scarce. The present review would assist physiotherapists in developing countries to utilize evidence-based criteria for the selection of gait training approaches post-stroke. Due to the environmental and contextual demands, the effect of interventions for recovery among stroke survivors should be improvised in low resource settings. This review can be a source of recommendation in giving effective strategies for clinical practice.

Use of Backward Walking Speed to Screen Dynamic Balance and Mobility Deficits in Older Adults Living Independently in the Community.

BACKGROUND AND PURPOSE: Older adults who live independently in the community are higher functioning and routinely ambulate in the community. Unrestricted community ambulation increases the likelihood of encountering precarious situations challenging balance. Sufficient dynamic balance is necessary to avoid falls. Currently used balance and mobility assessments may not sufficiently challenge dynamic balance to uncover mobility deficits in independent community-dwelling older adults. The purpose of this study was to investigate whether backward walking speed (BWS) can serve as an outcome measure to screen dynamic balance and mobility deficits in independent community-dwelling older adults. METHODS: A convenience sample of 30 older adults (73.68 ± 6.54 years) participated in this cross-sectional study. Participants walked backward on an instrumented walkway to record BWS. Other outcomes included forward walking speed (FWS), Community Balance and Mobility (CB&M) Scale, Falls Efficacy Scale-International (FES-I), Timed Up and Go (TUG) test, and 7-day average step count (ASC). A multivariate analysis of variance investigated the overall group differences between older adults at fall risk and those not at risk and was followed up by univariate tests. Pearson and spearman coefficients investigated associations between study outcomes. Youden's index assessed diagnostic accuracy. RESULTS AND DISCUSSION: Backward walking speed, CB&M, FES-I, ASC discriminated older adults at fall risk from those not at risk (P < .01) whereas FWS and TUG did not. Backward walking speed strongly correlated with challenging assessments of balance and mobility (CB&M, FES-I, and ASC) but only moderately correlated with the TUG. The CB&M Scale independently explained 53% variance in the BWS performance (P < .01). Youden's index was highest (Y = 0.6, sensitivity = 93%, and specificity = 67%) for BWS (0.73 m/s) compared with other study outcomes. CONCLUSIONS: Preliminary results suggest that BWS can screen for dynamic balance and mobility deficits in independent community-dwelling older adults. Accurate screening is the first step to capture early decline in function for independent community-dwelling older adults. Longitudinal follow-up studies are warranted to validate BWS as a screening tool.

Assessment of backward walking unmasks mobility impairments in post-stroke community ambulators.

Background: While over half of stroke survivors recover the ability to walk without assistance, deficits persist in the performance of walking adaptations necessary for safe home and community mobility. One such adaptation is the ability to walk or step backward. Post-stroke rehabilitation rarely includes backward walking (BW) assessment and BW deficits have not been quantified in post-stroke community ambulators. Objective: To quantify spatiotemporal and kinematic BW characteristics in post-stroke community ambulators and compare their performance to controls. Methods: Individuals post-stroke (n = 15, 60.1 ± 12.9 years, forward speed: 1.13 ± 0.23 m/s) and healthy adults (n = 12, 61.2 ± 16.2 years, forward speed: 1.40 ± 0.13 m/s) performed forward walking (FW) and BW during a single session. Step characteristics and peak lower extremity joint angles were extracted using 3D motion analysis and analyzed with mixed-method ANOVAs (group, walking condition). Results: The stroke group demonstrated greater reductions in speed, step length and cadence and a greater increase in double-support time during BW compared to FW (p < .01). Compared to FW, the post-stroke group demonstrated greater reductions in hip extension and knee flexion during BW (p < .05). The control group demonstrated decreased plantarflexion and increased dorsiflexion during BW, but these increases were attenuated in the post-stroke group (p < .05). Conclusions: Assessment of BW can unmask post-stroke walking impairments not detected during typical FW. BW impairments may contribute to the mobility difficulties reported by adults post-stroke. Therefore, BW should be assessed when determining readiness for home and community ambulation.

Validation of a speed-based classification system using quantitative measures of walking performance poststroke.

BACKGROUND: For clinical trials in stroke rehabilitation, self-selected walking speed has been used to stratify persons to predict functional walking status and to define clinical meaningfulness of changes. However, this stratification was validated primarily using self-report questionnaires. OBJECTIVE: This study aims to validate the speed-based classification system with quantitative measures of walking performance. METHODS: A total of 59 individuals who had hemiparesis for more than 6 months after stroke participated in this study. Spatiotemporal and kinetic measures included the percentage of total propulsion generated by the paretic leg (Pp), the percentage of the stride length accounted for by the paretic leg step length (PSR), and the percentage of the gait cycle spent in paretic preswing (PPS). Additional measures included the synergy portion of the Fugl-Meyer Assessment and the average number of steps/day in the home and community measured with a step activity monitor. Participants were stratified by self-selected gait speed into 3 groups: household (<0.4 m/s), limited community (0.4-0.8 m/s), and community (>0.8 m/s) ambulators. Group differences were analyzed using a Kruskal-Wallis H test with rank sums test post hoc analyses. RESULTS: Analyses demonstrated a main effect in all measures, but only steps/day and PPS demonstrated a significant difference between all 3 groups. CONCLUSIONS: Classifying individuals poststroke by self-selected walking speed is associated with home and community-based walking behavior as quantified by daily step counts. In addition, PPS distinguishes all 3 groups. Pp differentiates the moderate from the fast groups and may represent a contribution to mechanisms of increasing walking speed. Speed classification presents a useful yet simple mechanism to stratify subjects poststroke and may be mechanically linked to changes in PPS.

Addressing limitations of the Gait Variability Index to enhance its applicability: The enhanced GVI (EGVI).

Prior research has established the Gait Variability Index (GVI) as a composite measure of gait variability, based on spatiotemporal parameters, that is associated with functional outcomes. However, under certain circumstances the magnitude and directional specificity of the GVI is adversely affected by shortcomings in the calculation method. Here we present an enhanced gait variability index (EGVI) that addresses those shortcomings and improves the utility of the measure. The EGVI was further enhanced by removing some input spatiotemporal variables that captured overlapping/redundant information. The EGVI was used to reanalyze data from four previously published studies that used the original GVI. After removing data affected by the GVI's prior shortcomings, the association between EGVI and GVI values was stronger for the pooled dataset (r2 = 0.95) and for the individual studies (r2 = 0.88-0.98). The EGVI also revealed stronger associations between the index value and functional outcomes for some studies. The EGVI successfully addresses shortcomings in the GVI calculation that affected magnitude and directional specificity of the index. We have confirmed the validity of prior published work that used the original GVI, while also demonstrating even stronger results when these prior data were re-analyzed with the EGVI. We recommend that future research should use the EGVI as a composite measure of gait variability.

Sympathetic nervous system activity measured by skin conductance quantifies the challenge of walking adaptability tasks after stroke.

BACKGROUND: Walking adaptability tasks are challenging for people with motor impairments. The construct of perceived challenge is typically measured by self-report assessments, which are susceptible to subjective measurement error. The development of an objective physiologically-based measure of challenge may help to improve the ability to assess this important aspect of mobility function. The objective of this study to investigate the use of sympathetic nervous system (SNS) activity measured by skin conductance to gauge the physiological stress response to challenging walking adaptability tasks in people post-stroke. METHODS: Thirty adults with chronic post-stroke hemiparesis performed a battery of seventeen walking adaptability tasks. SNS activity was measured by skin conductance from the palmar surface of each hand. The primary outcome variable was the percent change in skin conductance level (ΔSCL) between the baseline resting and walking phases of each task. Task difficulty was measured by performance speed and by physical therapist scoring of performance. Walking function and balance confidence were measured by preferred walking speed and the Activities-specific Balance Confidence Scale, respectively. RESULTS: There was a statistically significant negative association between ΔSCL and task performance speed and between ΔSCL and clinical score, indicating that tasks with greater SNS activity had slower performance speed and poorer clinical scores. ΔSCL was significantly greater for low functioning participants versus high functioning participants, particularly during the most challenging walking adaptability tasks. CONCLUSION: This study supports the use of SNS activity measured by skin conductance as a valuable approach for objectively quantifying the perceived challenge of walking adaptability tasks in people post-stroke.

Dynamic balance during walking adaptability tasks in individuals post-stroke.

Maintaining dynamic balance during community ambulation is a major challenge post-stroke. Community ambulation requires performance of steady-state level walking as well as tasks that require walking adaptability. Prior studies on balance control post-stroke have mainly focused on steady-state walking, but walking adaptability tasks have received little attention. The purpose of this study was to quantify and compare dynamic balance requirements during common walking adaptability tasks post-stroke and in healthy adults and identify differences in underlying mechanisms used for maintaining dynamic balance. Kinematic data were collected from fifteen individuals with post-stroke hemiparesis during steady-state forward and backward walking, obstacle negotiation, and step-up tasks. In addition, data from ten healthy adults provided the basis for comparison. Dynamic balance was quantified using the peak-to-peak range of whole-body angular-momentum in each anatomical plane during the paretic, nonparetic and healthy control single-leg-stance phase of the gait cycle. To understand differences in some of the key underlying mechanisms for maintaining dynamic balance, foot placement and plantarflexor muscle activation were examined. Individuals post-stroke had significant dynamic balance deficits in the frontal plane across most tasks, particularly during the paretic single-leg-stance. Frontal plane balance deficits were associated with wider paretic foot placement, elevated body center-of-mass, and lower soleus activity. Further, the obstacle negotiation task imposed a higher balance requirement, particularly during the trailing leg single-stance. Thus, improving paretic foot placement and ankle plantarflexor activity, particularly during obstacle negotiation, may be important rehabilitation targets to enhance dynamic balance during post-stroke community ambulation.

Walking on uneven terrain in healthy adults and the implications for people after stroke.

BACKGROUND: One third of individuals after stroke report an inability to walk in the community. Community mobility requires walking adaptability - the ability to adjust one's stepping pattern to meet environmental demands and task goals. Walking on uneven terrain (e.g. grass, gravel) has unique requirements and is a critical component of walking adaptability that has not been investigated in the post-stroke population. OBJECTIVE: To summarize current knowledge of biomechanical and neuromuscular modifications during uneven terrain negotiation in healthy individuals and discuss implications of post-stroke impairments. METHODS: Review of eleven studies, identified through a search of relevant literature on PubMed and CINAHL. RESULTS: On uneven terrain, healthy adults demonstrate numerous gait modifications including a lowered center of mass, increased muscle co-contraction during stance and exaggerated or increased toe clearance during swing. After stroke, changes in muscle activity and limb coordination will likely result in difficulty or inability performing these modifications that healthy adults use to maintain stability and safety when walking on uneven terrain. CONCLUSIONS: Studies of biomechanical and neuromuscular control of walking on uneven terrain are needed to quantify mobility limitations in adults post-stroke. Such investigations will contribute to the understanding of mobility impairments after stroke and the design of critically important intervention strategies.

Anterior-posterior ground reaction forces as a measure of paretic leg contribution in hemiparetic walking.

BACKGROUND AND PURPOSE: Walking after stroke is characterized by slow gait speed, poor endurance, reduced quality and adaptability of walking patterns, and an inability to coordinate the legs. Estimates based on mechanical work calculations have suggested that the paretic leg does 30% to 40% of the total mechanical work over the gait cycle, regardless of hemiparetic severity, but these work estimates may not describe the contribution of each leg to forward propulsion. The purpose of this study was to establish a quantifiable link between hemiparetic severity and paretic leg contribution to propulsion during walking, which we propose to quantify using a measure based on the anterior-posterior ground reaction forces (A-P GRFs). METHODS: A total of 47 participants with chronic hemiparesis walked at self-selected speeds to collect spatiotemporal parameters and 3D GRFs. A 16-person subset also participated in a pedaling protocol to compare A-P GRF measures to established measures of paretic leg output. RESULTS: A-P GRF measures were correlated with both walking speed and hemiparetic severity. These measures were also strongly correlated with positive work and net work values obtained during the pedaling task. The percentage of total propulsion generated by the paretic leg (PP) was calculated and found to be 16%, 36%, and 49% for those with high, moderate, and low hemiparetic severity, respectively. CONCLUSIONS: PP was found to provide a quantitative measure of the coordinated output of the paretic leg. Further research on this measure of forward propulsion may lead to the provision of an effective tool for distinguishing functional compensation from physiological restitution.

The community balance and mobility scale alleviates the ceiling effects observed in the currently used gait and balance assessments for the community-dwelling older adults.

BACKGROUND AND PURPOSE: Currently used balance assessments show a ceiling effect and lack activities essential for community mobility in higher-functioning older adults. The aim of this study was to investigate the reliability and validity of the Community Balance and Mobility (CB&M) Scale in a high-functioning community-dwelling older adult population since the CB&M Scale includes assessment of several challenging tasks and may alleviate the ceiling effects observed in commonly used gait and balance assessments for this cohort. METHODS: A convenience sample of 40 older adults (73.4 ± 6.9 years) participated in this cross-sectional study. Previously standardized balance and mobility assessments measuring similar constructs as the CB&M were used for validation. Outcomes included Timed Up and Go Test, Berg Balance Scale (BBS), Dynamic Gait Index (DGI), Functional Reach Test (FRT), Short Physical Performance Battery (SPPB), 6-Minute Walk Test (6MWT), Activities Specific Balance Confidence scale (ABC), gait speed, and intraindividual gait variability. A falls questionnaire documented the history of falls. RESULTS: Rater reliability (ICC > 0.95) and internal consistency (α= .97) of the CB&M scale were high. CB&M scores demonstrated strong correlations with DGI, BBS, SPPB, and 6MWT (ρ= 0.70-0.87; P < .01); moderate correlations with falls history, TUG, ABC, and gait speed (ρ= 0.44-0.65; P < .01); and low correlations with FRT, swing and stance time variability (ρ= 0.34-0.37; P < .05). Dynamic Gait Index, BBS, SPPB, and ABC assessments demonstrated ceiling effects (7.5%-32.5%), while no floor or ceiling effects were noted on the CB&M. Logistic regression model showed that the CB&M scores significantly predicted falls history (χ(2) = 6.66, odds ratio = 0.92; P < .01). Area under the curve for the CB&M scale was 0.80 (95% CI: 0.65-0.95). A score of CB&M ≤ 39 was the optimal trade-off between sensitivity and specificity (sensitivity = 79%, specificity = 76%) and a score of CB&M ≤ 45 maximized sensitivity (sensitivity = 93%, specificity = 60%) to discriminate persons with 2 or more falls from those with fewer than 2 falls in the past year. DISCUSSION AND CONCLUSIONS: CB&M scale is reliable and valid to evaluate gait, balance, and mobility in community-dwelling older adults. Unlike some currently used balance and mobility assessments for the community-dwelling older adults, the CB&M scale did not show a ceiling in detection of balance and mobility deficits. In addition, cutoff scores have been proposed that might serve as criteria to discriminate older adults with balance and mobility deficits. The CB&M scale might enable assessment of balance and mobility limitations masked by other assessments and help design interventions to improve community mobility and sustain independence in the higher-functioning community-dwelling older adult.

Validity of the gait variability index in older adults: effect of aging and mobility impairments.

Gait variability, defined as the fluctuation in spatiotemporal characteristics between steps, is suggested to be a sensitive indicator of mobility deficits with aging and pathological processes. A challenge in quantifying gait variability is the decision of which spatiotemporal parameters to assess because gait parameters may exhibit different amounts of variability and may differentially relate to mobility performance. The Gait Variability Index (GVI), a composite measure of variability across several gait parameters, was previously developed to overcome this challenge. The present study seeks to validate the use of GVI in the older adult population. A retrospective analysis of gait and clinical data was conducted using data pooled from five prior studies. The final data set included 105 younger adults (YA, age<65) and 81 older adults (OA, age≥65). The GVI of OA (91.92±8.75) was significantly lower compared to the GVI of YA (100.79±7.99). Within OA, the GVI was significantly lower (p<0.0001) in individuals with mobility deficits (84.35±9.03) compared to those with high mobility function (96.35±8.86). Furthermore, GVI was associated with mobility function, including walking speed and performance on the Berg Balance Scale. Our findings imply that the GVI is a valid assessment for gauging spatiotemporal gait variability in older adults, is sensitive to differentiate between high-functioning older adults and those with mild to moderate mobility deficits and is associated with some clinical measures of functional mobility and balance.

How Well Do Functional Assessments of Mobility and Balance Discriminate Fallers and Recurrent Fallers from Non-Fallers among Ambulatory Older Adults in the Community?

PURPOSE: 1) To compare the ability of functional mobility and balance assessments in discriminating fallers from non-fallers and recurrent fallers from those with fewer or no falls. 2) To compare the discriminatory accuracy of cut-off scores specific to this study sample with that of cut-off scores proposed in the literature for community-dwelling older adults. METHODS: In a sample of 39 ambulatory older adults living independently in the community, fallers were identified on the basis of number of falls in the past year. Seven functional tests of mobility and balance were used to identify fallers and recurrent fallers on the basis of their fall history. RESULTS: Discrimination of fallers from non-fallers was poor: Only a high-level balance assessment significantly discriminated these groups (p=0.0498, area under the curve [AUC]=0.68). Four assessments significantly discriminated recurrent fallers from those with fewer or no falls (ps=0.006-0.009), but their discriminatory powers were not significantly different from one another (AUCs=0.77-0.80, p>0.05). For two assessments, cutoff scores based on the study sample enhanced discriminatory accuracy relative to the literature-based cutoff scores. CONCLUSIONS: To improve fall prediction for ambulatory community-dwelling older adults, future prospective studies should consider including high-level mobility and balance assessments and targeting cutoff scores to the level of function of this relatively high-functioning population.

Objet : Comparer la capacité qu'ont les évaluations de la mobilité fonctionnelle et de l'équilibre d'établir une distinction entre les personnes qui chutent et les personnes qui ne chutent pas, et entre celles qui chutent fréquemment et celles qui chutent peu ou jamais; comparer la précision en matière de distinction des points de coupure propres à l'échantillon de cette étude par rapport à ceux proposés dans la littérature concernant les personnes âgées qui résident dans la collectivité. Méthodes : Dans un échantillon de 39 personnes âgées mobiles qui vivent en autonomie dans la collectivité, les personnes qui chutent ont été déterminées selon le nombre de chutes faites au cours de l'année précédente. Sept tests fonctionnels concernant la mobilité et l'équilibre ont été utilisés pour déterminer les personnes qui chutent et les personnes qui chutent fréquemment selon leurs antécédents en matière de chutes. Résultats : La distinction des personnes qui chutent des personnes qui ne chutent pas était faible: seule une évaluation avancée de l'équilibre a établi une distinction importante entre ces groupes (p=0,0498, AUC=0,68). Quatre évaluations ont établi une distinction importante entre les personnes qui chutent fréquemment par rapport à celles qui chutent peu souvent ou jamais (p=0,006 à 0,009), mais leurs puissances de distinction n'étaient pas assez différentes les unes des autres (AUC=0,77 à 0.80, p>0,05). Dans le cadre de deux évaluations, les points de coupure fondés sur l'échantillon de l'étude ont amélioré la précision en matière de distinction des points de coupure établis selon la littérature. Conclusions : Pour améliorer la prédiction des chutes chez les personnes âgées qui résident dans la collectivité, les prochaines études prospectives doivent prendre en considération l'inclusion d'évaluations avancées de la mobilité et de l'équilibre et cibler les points de coupure au niveau de cette population hautement fonctionnelle.

Walking adaptability after a stroke and its assessment in clinical settings.

Control of walking has been described by a tripartite model consisting of stepping, equilibrium, and adaptability. This review focuses on walking adaptability, which is defined as the ability to modify walking to meet task goals and environmental demands. Walking adaptability is crucial to safe ambulation in the home and community environments and is often severely compromised after a stroke. Yet quantification of walking adaptability after stroke has received relatively little attention in the clinical setting. The objectives of this review were to examine the conceptual challenges for clinical measurement of walking adaptability and summarize the current state of clinical assessment for walking adaptability. We created nine domains of walking adaptability from dimensions of community mobility to address the conceptual challenges in measurement and reviewed performance-based clinical assessments of walking to determine if the assessments measure walking adaptability in these domains. Our literature review suggests the lack of a comprehensive well-tested clinical assessment tool for measuring walking adaptability. Accordingly, recommendations for the development of a comprehensive clinical assessment of walking adaptability after stroke have been presented. Such a clinical assessment will be essential for gauging recovery of walking adaptability with rehabilitation and for motivating novel strategies to enhance recovery of walking adaptability after stroke.

Revisiting physiologic and psychologic triggers that increase spasticity.

OBJECTIVE: The aims of this study were to systematically identify and summarize the literature examining the impact of physiologic and psychologic triggers on spasticity and discuss the evidence supporting various types of triggers. DESIGN: PubMed, EMBASE, CINAHL, and PEDro databases were searched using specific keyword combinations. Only studies using clinical tests or self-reports of spasticity were included. RESULTS: A total of 1152 articles were scanned for relevance, and of 44 relevant articles, 24 were reviewed. Pregnancy, posture, cold, circadian rhythm, and skin conditions increased spasticity and were measured using objective clinical tests. Self-reports of spasticity suggest that triggers such as bowel- and bladder-related issues, menstrual cycle, mental stress, and tight clothing can all increase spasticity. No literature evidence of increase in spasticity in response to heterotopic ossification, hemorrhoids, deep vein thrombosis, fever, and sleep patterns was found. CONCLUSIONS: Although self-reports indicate a strong possibility of increasing spasticity, without objective examination, the true effects of these triggers on spasticity remain inconclusive. Most studies reviewed here were performed in the spinal cord injury population; therefore, it is not known whether these triggers induce similar effects in persons with other neurologic etiologies.

Foot placement in a body reference frame during walking and its relationship to hemiparetic walking performance.

BACKGROUND: Foot placement during walking is closely linked to the body position, yet it is typically quantified relative to the other foot. The purpose of this study was to quantify foot placement patterns relative to body post-stroke and investigate its relationship to hemiparetic walking performance. METHODS: Thirty-nine participants with hemiparesis walked on a split-belt treadmill at their self-selected speeds and 20 healthy participants walked at matched slow speeds. Anterior-posterior and medial-lateral foot placements (foot center-of-mass) relative to body (pelvis center-of-mass) quantified stepping in body reference frame. Walking performance was quantified using step length asymmetry ratio, percent of paretic propulsion and paretic weight support. FINDINGS: Participants with hemiparesis placed their paretic foot further anterior than posterior during walking compared to controls walking at matched slow speeds (P<.05). Participants also placed their paretic foot further lateral relative to pelvis than non-paretic (P<.05). Anterior-posterior asymmetry correlated with step length asymmetry and percent paretic propulsion but some persons revealed differing asymmetry patterns in the translating reference frame. Lateral foot placement asymmetry correlated with paretic weight support (r=.596; P<.001), whereas step widths showed no relation to paretic weight support. INTERPRETATION: Post-stroke gait is asymmetric when quantifying foot placement in a body reference frame and this asymmetry related to the hemiparetic walking performance and explained motor control mechanisms beyond those explained by step lengths and step widths alone. We suggest that biomechanical analyses quantifying stepping performance in impaired populations should investigate foot placement in a body reference frame.

Variability in spatiotemporal step characteristics and its relationship to walking performance post-stroke.

Gait variability is suggested to be a quantifiable measure to evaluate mobility impairments. However, it is unknown whether gait variability could be used as a marker of impaired walking performance post-stroke. Therefore, the purpose of this study was to determine whether gait variability measures could be used as walking performance measures post-stroke. Hemiparetic variability was compared to healthy gait variability and associated to clinical assessments that evaluate impaired performance post-stroke. Spatiotemporal characteristics were collected from 94 persons with post-stroke hemiparesis and 22 similarly aged healthy persons as they walked over an instrumented mat. Gait variability was calculated as the standard deviation in step lengths, stride widths, pre-swing, swing and stride times. Hemiparetic performance was evaluated using lower-extremity Fugl-Meyer grading, dynamic gait index scale (available in population sub-sets) and an asymmetry index. Results revealed that variability increased in step length, swing, pre-swing and stride times (p<.001) during hemiparetic walking as compared to healthy gait. Paretic leg swing time variability was increased compared to the non-paretic during hemiparetic walking (p<.001). Between-leg differences in variability for other spatiotemporal characteristics were revealed in participants with the most impaired performance. Further, increased step variability and reduced width variability related to poor performance outcomes (severe hemiparesis, asymmetrical gait and poor balance). Patterns of gait variability were evident within sub-groups of the hemiparetic population. Results of this study suggest that between-leg differences in swing and pre-swing time variability, increased step length and stride time variability and decreased width variability are quantifiable markers of impaired walking performance poststroke.

Relationship between step length asymmetry and walking performance in subjects with chronic hemiparesis.

OBJECTIVE: To understand the relationship between step length asymmetry and hemiparetic walking performance. DESIGN: Descriptive. SETTING: Gait analysis laboratory. PARTICIPANTS: Convenience sample of 49 subjects with chronic hemiparesis. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Subjects walked at their self-selected walking speed over both an instrumented mat and forceplates to collect spatiotemporal parameters and ground reaction forces, respectively. Step length asymmetry was quantified by using a step length ratio (SLR) defined as paretic step length divided by nonparetic step length. Paretic leg propulsion, self-selected walking speed, hemiparetic severity (assessed by Brunnstrom stages of motor recovery), and some spatiotemporal walking parameters quantified the hemiparetic walking performance. Paretic leg propulsion was quantified by the paretic propulsion (P(P)) ratio, calculated as the percentage contribution of paretic leg to the total propulsive impulse. RESULTS: Significant negative correlation (r=-.78) was revealed between SLR and P(P), indicating that subjects generating less propulsive force with the paretic leg walked asymmetrically with longer paretic steps than nonparetic steps. SLR and self-selected walking speed revealed a weaker correlation (r=-.35), whereas hemiparetic severity correlated strongly with SLR (rho=-.53). CONCLUSIONS: Step length asymmetry is related to propulsive force generation during hemiparetic walking. Subjects generating least paretic propulsion walk with relatively longer paretic steps. This suggests that one of the mechanisms for the longer paretic step may be the relatively greater compensatory nonparetic leg propulsion. Further, those with more severe hemiparesis (those dependent on abnormal flexor and extensor synergies) walk with the longest paretic steps relative to nonparetic. Finally, our results indicated that asymmetrical step lengths may not necessarily limit the self-selected walking speed, likely due to other compensatory mechanisms.