The Immediate Effects of Different Types of Augmented Feedback on Fast Walking Speed Performance and Intrinsic Motivation After Stroke.

Objective: To examine the immediate effects of different types of augmented feedback on walking speed and intrinsic motivation post-stroke. Design: A within-subjects repeated-measures design. Setting: A university rehabilitation center. Participants: Eighteen individuals with chronic stroke hemiparesis with a mean age of 55.67±13.63 years and median stroke onset of 36 (24, 81) months (N=18). Interventions: Not applicable. Primary outcome: Fast walking speed measured on a robotic treadmill for 13 meters without feedback and 13 meters with augmented feedback on each of the 3 experimental conditions: (1) without virtual reality (VR), (2) with a simple VR interface, and (3) with VR-exergame. Intrinsic motivation was measured using the Intrinsic Motivation Inventory (IMI). Results: Although the differences were not statistically significant, fast-walking speed was higher in the augmented feedback without VR (0.86±0.44 m/s); simple VR interface (0.87±0.41 m/s); VR-exergame (0.87±0.44 m/s) conditions than in the fast-walking speed without feedback (0.81±0.40 m/s) condition. The type of feedback had a significant effect on intrinsic motivation (P=.04). The post hoc analysis revealed borderline significance on IMI-interest and enjoyment between the VR-exergame condition and the without-VR condition (P=.091). Conclusion: Augmenting feedback affected the intrinsic motivation and enjoyment of adults with stroke asked to walk fast on a robotic treadmill. Additional studies with larger samples are warranted to examine the relations among these aspects of motivation and ambulation training outcomes.

Using Nursing Assessments of Mobility and Activity to Prioritize Patients Most Likely to Need Rehabilitation Services.

OBJECTIVE: To identify nursing assessments of mobility and activity associated with lower-value rehabilitation services. DESIGN: Retrospective cohort analysis of admissions from December 2016 to September 2019 SETTING: Medicine, neurology, and surgery units (n=47) at a tertiary hospital. PARTICIPANTS: We included patients with a length of stay ≥7 days on units that routinely assessed patient function (n=18,065 patients). INTERVENTIONS: Not applicable. MAIN OUTCOME: We examined the utility of nursing assessments of function to identify patients who received lower-value rehabilitation consults, defined as those who received ≤1 therapy visit. MEASURES: Patient function was assessed using 2 Activity Measure for Post-Acute Care (AM-PAC or "6 clicks") inpatient short forms: (1) basic mobility (eg, bed mobility, walking) and (2) daily activity (eg, grooming, toileting). RESULTS: Using an AM-PAC cutoff value of ≥23 correctly identified 92.5% and 98.7% of lower-value physical therapy and occupational therapy visits, respectively. In our cohort, using a cutoff value of ≥23 on the AM-PAC would have eliminated 3482 (36%) of lower-value physical therapy consults and 4076 (34%) of lower-value occupational therapy consults. CONCLUSIONS: Nursing assessment, using AM-PAC scores, can be used to help identify lower-value rehabilitation consults, which can then be reallocated to patients with greater rehabilitation needs. Based on our results, an AM-PAC cutoff value of ≥23 can be used as a guide to help prioritize patients with greater rehabilitation needs.

Revealing the tension: The relationship between high fall risk categorization and low patient mobility.

BACKGROUND: Using an inpatient fall risk assessment tool helps categorize patients into risk groups which can then be targeted with fall prevention strategies. While potentially important in preventing patient injury, fall risk assessment may unintentionally lead to reduced mobility among hospitalized patients. Here we examined the relationship between fall risk assessment and ambulatory status among hospitalized patients. METHODS: We conducted a retrospective cohort study of consecutively admitted adult patients (n = 48,271) to a quaternary urban hospital that provides care for patients of broad socioeconomic and demographic backgrounds. Non-ambulatory status, the primary outcome, was defined as a median Johns Hopkins Highest Level of Mobility <6 (i.e., patient walks less than 10 steps) throughout hospitalization. The primary exposure variable was the Johns Hopkins Fall Risk Assessment Tool (JHFRAT) category (Low, Moderate, High). The capacity to ambulate was assessed using the Activity Measure for Post-Acute Care (AM-PAC). Multivariable regression analysis controlled for clinical demographics, JHFRAT items, AM-PAC, comorbidity count, and length of stay. RESULTS: 8% of patients at low risk for falls were non-ambulatory, compared to 25% and 54% of patients at moderate and high risk for falls, respectively. Patients categorized as high risk and moderate risk for falls were 4.6 (95% CI: 3.9-5.5) and 2.6 (95% CI: 2.4-2.9) times more likely to be non-ambulatory compared to patients categorized as low risk, respectively. For patients with high ambulatory potential (AM-PAC 18-24), those categorized as high risk for falls were 4.3 (95% CI: 3.5-5.3) times more likely to be non-ambulatory compared to patients categorized as low risk. CONCLUSIONS: Patients categorized into higher fall risk groups had decreased mobility throughout their hospitalization, even when they had the functional capacity to ambulate.

Rehabilitating the Patient, the Self, and the Profession: The Journey of an Afro-Latina in Physical Therapy.

Higher education is not immune to inequities, although universities often state that those inequities do not align with their mission. Change is often obstructed by blindness to flaws, especially structural barriers that lead to unequal success. In this article, the author utilizes her lived experience to highlight structures at play that go beyond a single story. These experiences are divided in five major themes: 1) representation, 2) belonging, 3) language, 4) class, and 5) sexuality and harassment. The author analyzes each theme combining detailed descriptions of how multiple identities and the socio-political-cultural environment intersect to impact success in all aspects of rehabilitation. In particular, she explores the conflict that occurs when acceptable behaviors, skills, and identities are not embodied by the people who have been underrepresented and marginalized in rehabilitation. Each section concludes with ideas on how to challenge deep-rooted hierarchies that foster division and exclusion. To truly serve diverse communities equitably, we must 1) transform rehabilitation education, clinical practice, and research; 2) embed ourselves into the communities that surround our universities; 3) develop a collective cyclical process of learning to replace behaviors that harm others; and 4) dismantle old practices that prevent everyone from belonging. Until that happens, well-intentioned attempts to diversify the field will remain hollow, ineffective, and harmful.

Injustice Through Cultural Lens: A Pilot Qualitative Exploration of Pain-Related Injustice Appraisals Among Arab-Americans with Chronic Low Back Pain.

The current qualitative study sought to obtain an in-depth understanding of how Arab-Americans conceptualize perceived injustice concerning their chronic low back pain (CLBP) by reflecting on the Injustice Experience Questionnaire (IEQ). Twelve Arab-American adults with CLBP were recruited from a metropolitan area in Alabama using a purposive sampling technique. Participants took part in individual, face-to-face, semi-structured interviews reflecting on each statement from the IEQ. Descriptive data analysis was generated for demographic and pain variables. Directed content analysis was conducted to identify themes and sub-themes. 'Blame and unfairness' and 'severity and irreparability of loss,' the 2 established theoretical factors comprising pain-related injustice appraisal were used as predominant themes. Acceptance emerged as an inductive theme with the following sub-themes: positive appraisal and resilience, attempts to reduce pain, religious values and fate, and belief that everything happening for a reason. The influence of religion was noted across all themes. The current pilot findings suggest that Arabic culture, heavily infused with Islamic beliefs, influences how Arab-Americans conceptualize pain-related injustice appraisals. Additional exploration of the cultural appropriateness of the IEQ among individuals of Arab background is needed to further elaborate on the subject of faith and religious belief suggested by the current study. Perspective: Although the study findings largely reflected established injustice literature constructs, several emergent themes regarding pain-related injustice appraisal were influenced by the participants' culture and religious beliefs. These findings may indicate that specific psychotherapeutic approaches that have been proven effective among some groups may not function similarly in other populations.

Effects of different types of augmented feedback on intrinsic motivation and walking speed performance in post-stroke: A study protocol.

INTRODUCTION: During recovery from stroke, augmented performance feedback can be applied with simple displays of metrics, as well as enhanced with virtual reality (VR) and exergames. VR, as augmented feedback, can provided to enhance walking speed after six months of stroke onset. There are several mechanisms to induce improved motor performance and motivation. Our objective is to design a study to demonstrate the different effects of augmented feedback, simple VR and exergaming applications on motivation and walking speed performance in post stroke. METHODS: Eighteen individuals with chronic stroke will be recruited and asked to walk as fast and safely as they can while on a robotic, user speed-driven treadmill (KineAssist-MX®) in three conditions: (1) with simple visual augmented feedback, but without a VR interface, (2) with a basic VR interface and (3) with a VR exergame. The main outcome measures are 30 s of fast walking speed and intrinsic motivation measured using the Intrinsic Motivation Inventory-Interest and Enjoyment Subscale. A within-subjects repeated measure ANOVA test and post hoc analysis will be used to determine the differences in changes of maximum walking speeds among the three performance conditions. DISCUSSION: The additive impact of augmented feedback with or without VR and VR-exergames on motivation and walking speed during stroke rehabilitation is unknown, a gap we aim to address. Our findings will contribute key details regarding the effects of different types of augmented feedback on walking speed and intrinsic motivation and to the refinement of theoretical frameworks that guide the design and implementation of augmented feedback during recovery after stroke.

A comparative approach to quantifying provision of acute therapy services.

ABSTRACT: This study aims to compare delivery of acute rehabilitation therapy using metrics reflecting distinct aspects of rehabilitation therapy services. Seven general medical-surgical hospitals in Illinois and Indiana prospectively collected rehabilitation therapy data. De-identified data on all patients who received any type of acute rehabilitation therapy (n = 35,449) were extracted and reported as aggregate of minutes of therapy services per discipline. Metrics included therapy types, total minutes, and minutes per day (intensity), as charted by therapists. Extended hospital stay was defined as a length of stay (LOS) longer than Medicare's geometric mean LOS. Discharge destination was coded as postacute care or home discharge. Substantial variability was observed in types, number of minutes, and intensity of therapy services by condition and hospital. The odds of an extended hospital stay increased with increased number of minutes, increased number of therapy types, and decreased with increased rehabilitation intensity. This comparative approach to assessing provision of acute therapy services reflect differential effects of service provision on LOS and discharge destination. Investigators, policymakers, and hospital administrators should examine multiple metrics of rehabilitation therapy provision when evaluating the impact of health care processes on patient outcomes.

Trade-Offs in Quality-of-Life Assessment Between the Modified Rankin Scale and Neuro-QoL Measures.

INTRODUCTION: We aimed to describe the physical and cognitive health of patients with differing levels of post-stroke disability, as defined by modified Rankin Scale (mRS) scores. We also compared cross-sectional correlations between the mRS and the Quality of Life in Neurological Disorders (Neuro-QoL) T-scores to longitudinal correlations of change estimates from each measure. METHODS: Mean Neuro-QoL T-scores representing mobility, dexterity, executive function, and cognitive concerns were compared among mRS subgroups. Fixed-effects regression models with robust standard errors estimated correlations among mRS and Neuro-QoL domain scores and correlations among longitudinal change estimates. These change estimates were then compared to distribution-based estimates of minimal clinically important differences. RESULTS: Seven hundred forty-five patients with ischemic stroke (79%) or transient ischemic attack (21%) were enrolled in this longitudinal observational study of post-stroke outcomes. Larger differences in cognitive function were observed in the severe mRS groups (ie, 4-5) while larger differences in physical function were observed in the mild-moderate mRS groups (ie, 0-2). Cross-sectional correlations among mRS and Neuro-QoL T-scores were high (r = 0.61-0.83), but correlations among longitudinal change estimates were weak (r = 0.14-0.44). CONCLUSIONS: Findings from this study undermine the validity and utility of the mRS as an outcome measure in longitudinal studies in ischemic stroke patients. Nevertheless, strong correlations indicate that the mRS score, obtained with a single interview, is efficient at capturing important differences in patient-reported quality of life, and is useful for identifying meaningful cross-sectional differences among clinical subgroups.

Differential Effects of Time to Initiation of Therapy on Disability and Quality of Life in Patients With Mild and Moderate to Severe Ischemic Stroke.

OBJECTIVE: To assess the effect of time to acute therapy on health-related quality of life (HRQoL) and disability after ischemic stroke. DESIGN: Prospective cohort study. SETTING: Comprehensive stroke care center in a large metropolitan city. PARTICIPANTS: Patients (N=553; mean age, 67 y; 51.9% male; 64.4% white; 88.8% ischemic stroke) with ischemic stroke or transient ischemic attack (TIA) enrolled in a longitudinal observational study between August 2012 to January 2014 who received rehabilitation services. INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: Disability status was assessed with the modified Rankin Scale (mRS) and Barthel Index (BI). HRQoL was assessed using the Quality of Life in Neurological Disorders measures of executive function, general cognitive concerns, upper extremity dexterity, and lower extremity mobility. Time to therapy consult and treatment were defined as the number of days from hospital admission to initial consult by a therapist and number of days from hospital admission to initial treatment, respectively. RESULTS: Among the participants, the median number of days from hospital admission to acute therapy consult was 2 days (interquartile range, 1-3d). Multivariable linear and logistic regression models indicated that for those with the National Institutes of Health Stroke Scale (NIHSS) score<5, longer time to therapy consult was associated with worse BI scores (BI=100; odds ratio [OR], 0.818; P=.008), executive function T scores (b=-0.865; P=.001), and general cognitive concerns T scores (b=-0.609; P=.009) at 1-month in adjusted analyses. In those with NIHSS score≥5, longer time to therapy treatment led to increased disability (ie, mRS≥ 2; OR, 1.15; P=.039) and lower extremity mobility T scores (b=-0.591; P=.046) at 1 month in adjusted analyses. CONCLUSIONS: Longer time to initiation of acute therapy has differential effects on poststroke disability and HRQoL up to 1-month after ischemic stroke and TIA. The effect of acute therapy consult is more notable for those with mild deficits, while the effect of acute therapy treatment is more notable for those with moderate to severe deficits. Minimizing time to therapy consults and treatments in the acute hospital period might improve outcomes after ischemic stroke and TIA.

Association between ambulatory status and call bell use in hospitalized patients-A retrospective cohort study.

AIM: Characterize the relationship between patient ambulatory status and in-hospital call bell use. BACKGROUND: Although call bells are frequently used by patients to request help, the relationship between physical functioning and call bell use has not been evaluated. METHODS: Retrospective cohort study of 944 neuroscience patients hospitalized in a large academic urban medical centre between April 1, 2014 and August 1, 2014. We conducted multiple linear regression analyses with number of daily call bells from each patient as the primary outcome and patients' average ambulation status as the primary exposure variable. RESULTS: The mean number of daily call bell requests for all patients was 6.9 (6.1), for ambulatory patients 5.6 (4.8), and for non-ambulatory patients, it was 7.7 (6.6). Compared with non-ambulatory patients, ambulatory patients had a mean reduction in call bell use by 1.7 (95% CI 2.5 to -0.93, p < .001) calls per day. In a post hoc analysis, patients who could walk >250 feet had 5 fewer daily call bells than patients who were able to perform in-bed mobility. CONCLUSION: Ambulatory patients use their call bells less frequently than non-ambulatory patients. IMPLICATIONS FOR NURSING MANAGEMENT: Frequent use of call bells by non-ambulatory patients can place additional demands on nursing staff; patient mobility status should be considered in nurse workload/patient assignment.

Longer Time Before Acute Rehabilitation Therapy Worsens Disability After Intracerebral Hemorrhage.

OBJECTIVE: Assess the association of time to initiation of acute rehabilitation therapy with disability after intracerebral hemorrhage (ICH) and identify predictors of time to initiation of rehabilitation therapy. DESIGN: Retrospective data analysis of prospectively collected data from an ongoing observational cohort study. SETTING: Large comprehensive stroke center in a metropolitan area. PARTICIPANTS: Adults with ICH consecutively admitted (n=203). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Disability was assessed with the modified Rankin Scale (mRS), with poor outcome defined as mRS 4-6 (dependence or worse). Time to initiation of acute rehabilitation therapy was defined as the number of days between hospital admission and the first consult by any rehabilitation therapy specialist (eg, physical therapy, occupational therapy, speech therapy). RESULTS: The median number of days from hospital admission to initiation of acute rehabilitation therapy was 3 (range=2-7). Multivariable logistic regression models indicated that each additional day between admission and initiation of acute rehabilitation therapy was associated with increased odds of poor outcome at 30 days (adjusted odds ratio [OR]=1.151; 95% confidence interval [CI]=1.044-1.268; P=.005) and at 90 days (adjusted OR=1.107; 95% CI=1.003-1.222; P=.044) for patients with ICH. A multivariable linear regression model used to identify the predictors of time to initiation of rehabilitation therapy identified heavy drinking (>5 drinks per day), premorbid mRS<4, presence of pulmonary embolism, and longer length of stay in the intensive care unit as independent predictors of later initiation of acute rehabilitation therapy. CONCLUSIONS: Longer time to initiation of acute rehabilitation therapy after ICH may have persistent effects on poststroke disability. Delays in acute rehabilitation therapy consults should be minimized and may improve outcomes after ICH.

Measuring Self-Reported Physical Function in Individuals With TBI: Development of the TBI-QOL Mobility and Upper Extremity Item Banks and Short Forms.

OBJECTIVES: To describe the development and field testing of the patient-reported outcome measures of Mobility and Upper Extremity function from the Traumatic Brain Injury Quality of Life (TBI-QOL) measurement system, and to evaluate the use of computer adaptive testing. SETTING: Five rehabilitation facilities funded as part of the TBI Model Systems network. PARTICIPANTS: Individuals with complicated mild, moderate, or severe traumatic brain injury (n = 590). INTERVENTIONS: Not available. OUTCOME MEASURES: TBI-QOL Mobility and Upper Extremity item banks. RESULTS: Item response theory and factor analyses supported the unidimensionality of the Mobility and Upper Extremity banks. Descriptive statistics showed a ceiling effect for both measures. Simulated computer adaptive tests (CATs) showed that measurement precision was maintained across administration formats for both measures. The Upper Extremity CAT showed a loss of precision for individuals without impairment and that a higher number of items were required to achieve sufficiently precise measurement, compared to the Mobility CAT. CONCLUSIONS: The TBI-QOL Upper Extremity and Mobility item banks achieved good breadth of coverage, particularly among those individuals who have experienced some degree of functional limitation. The use of CAT administration minimizes respondent burden, while allowing for the comprehensive assessment of adults with TBI. The combined use of the TBI-QOL with performance-based measures could guide the development of targeted rehabilitation treatments.

Patients With Greater Stroke Severity and Premorbid Disability Are Less Likely to Receive Therapist Consultations and Intervention During Acute Care Hospitalization.

BACKGROUND: A substantial number of patients with stroke never receive acute care therapy services, despite the fact that therapy after stroke reduces the odds of death and disability and improves patients' functioning. OBJECTIVE: The aim of this study was to estimate the proportion of and factors associated with receipt of therapist consultations and interventions during acute care hospitalization following ischemic and hemorrhagic stroke. DESIGN: This was a single-center longitudinal observational study. METHODS: Adults with a diagnosis of ischemic or hemorrhagic stroke (N = 1366) were enrolled during their hospitalization in an acute stroke center in a large metropolitan area. The main outcomes were receipt of therapist consultations, interventions, or both. RESULTS: Participants with acute hemorrhagic stroke (intracerebral: odds ratio [OR] = 0.34 [95% CI = 0.19-0.60]; subarachnoid: OR = 0.52 [95% CI = 0.28-0.99]) and with greater stroke severity by National Institutes of Health Stroke Scale (NIHSS) score (NIHSS score of > 15: OR = 0.34 [95% CI = 0.23-0.51]) were less likely to receive therapist consultations. Participants with moderate stroke severity (NIHSS score of 6-15: OR = 1.43 [95% CI = 1.01-2.33]) were more likely to receive therapy interventions. Those who were able to ambulate before admission were more than 5 times as likely to receive therapy interventions (OR = 5.08 [95% CI = 1.91-13.52]). Also, participants with longer lengths of stay (ie, more intensive care unit and non-intensive care unit days) were more likely to receive therapist consultations and interventions. Tests or procedures were the most common reasons for unsuccessful attempts to complete therapist consultations. LIMITATIONS: Lack of operational and qualitative data prohibited detailed explorations of barriers to delivery of therapist consultations and interventions. CONCLUSIONS: Approximately 1 in 4 participants with acute stroke received neither a consultation nor an intervention. Efforts to improve the delivery of acute care therapy services are needed to optimize care for these people.

Classification of Mild Stroke: A Mapping Review.

Persons with mild stroke experience motor and cognitive impairments that negatively affect their health and quality of life. To address these deficits, it is essential for clinicians and researchers to precisely identify mild stroke survivors. Despite the fact that half of all strokes are categorized as mild, no standards exist on what constitutes a "mild" stroke. The purpose of this study is to summarize the current classification of mild stroke using a mapping review approach. Strategies to categorize "mild stroke" severity were explored in 188 papers indexed in the PubMed database. The results indicate that there was substantial variability in the procedures and scoring criteria used to determine mild stroke. To identify persons with mild stroke, researchers have largely applied assessment instruments developed to inform acute stroke care (eg, National Institutes of Health Stroke Scale, Modified Rankin Scale, Barthel Index). Unfortunately, these approaches demonstrate floor effects and fail to detect the long-term disabling impairments that often limit the outcomes of mild stroke survivors. Additional research is warranted to suggest an evidence-based mild stroke categorization strategy that enhances diagnosis, treatment, and referral decisions to the benefit of mild stroke survivors.

Data Sharing and Data Registries in Physical Medicine and Rehabilitation.

The field of physical medicine & rehabilitation (PM&R), along with all the disciplines it encompasses, has evolved rapidly in the past 50 years. The number of controlled trials, systematic reviews, and meta-analyses in PM&R increased 5-fold from 1998 to 2013. In recent years, professional, private, and governmental institutions have identified the need to track function and functional status across providers and settings of care and on a larger scale. Because function and functional status are key aspects of PM&R, access to and sharing of reliable data will have an important impact on clinical practice. We reviewed the current landscape of PM&R databases and data repositories, the clinical applicability and practice implications of data sharing, and challenges and future directions. We included articles that (1) addressed any aspect of function, disability, or participation; (2) focused on recovery or maintenance of any function; and (3) used data repositories or research databases. We identified 398 articles that cited 244 data sources. The data sources included 66 data repositories and 179 research databases. We categorized the data sources based on their purposes and uses, geographic distribution, and other characteristics. This study collates the range of databases, data repositories, and data-sharing mechanisms that have been used in PM&R internationally. In recent years, these data sources have provided significant information for the field, especially at the population-health level. Implications and future directions for data sources also are discussed.

Effect of progressive horizontal resistive force on the comfortable walking speed of individuals post-stroke.

BACKGROUND: Individuals post-stroke select slow comfortable walking speeds (CWS) and the major factors used to select their CWS is unknown. OBJECTIVE: To determine the extent to which slow CWS post-stroke is achieved through matching a relative force output or targeting a particular walking speed. METHODS: Ten neurologically nonimpaired individuals and fourteen chronic stroke survivors with hemiplegia were recruited. Participants were instructed to "walk at the speed that feels most comfortable" on a treadmill against 12 progressively increasing horizontal resistive force levels applied at the pelvis using a robotic system that allowed participant to self-select their walking speed. We compared slope coefficients of the simple linear regressions between the observed normalized force vs. normalized speed relationship in each group to a slope of -1.0 (i.e. ideal slope for a constant relative force output) and 0.0 (i.e. ideal slope for a constant relative speed). We also compared slope coefficients between groups. RESULTS: The slope coefficients were significantly greater than -1.0 (p < 0.001 for both) and significantly less than 0 (p < 0.001 for both). However, compared with nonimpaired individuals, people post-stroke were less able to maintain their walking speed (p = 0.003). CONCLUSIONS: The results of this study provide evidence for a complex interaction between the regulation of relative force output and intention to move at a particular speed in the selection of the CWS for individuals post-stroke. This would suggest that therapeutic interventions should not only focus on task specific lower-limb strengthening exercises (e.g. walking against resistance), but should also focus on increasing the range of speeds at which people can safely walk.

Characteristics of horizontal force generation for individuals post-stroke walking against progressive resistive forces.

BACKGROUND: Walking, while experiencing horizontal resistive forces, can allow researchers to assess characteristics of force generation in a task specific manner for individuals post-stroke. METHODS: Ten neurologically nonimpaired individuals (mean age 52 years) and fourteen chronic stroke survivors (mean age 54 years) with hemiparesis walked in the treadmill-based KineAssist Walking and Balance System, while experiencing twelve progressive horizontal resistive forces at their comfortable walking speed. Slope coefficients of the observed force-velocity relationship were quantified and submitted to an iterative k-means cluster analysis to test for subgroups within the post-stroke sample. Extrapolated force values for individuals were quantified by extrapolating the line of best fit of the force-velocity relationship to the x-intercept. FINDINGS: Within the post-stroke group, six individuals were clustered into a high sensitivity group, i.e., large reduction in speed with resistance, and eight were clustered into a low sensitive group, i.e., small reduction in speed with resistance. The low sensitivity group was similar to non-impaired individual. The extrapolated force was significantly higher for non-impaired individuals compared to individuals post-stroke in either the high or low sensitivity group. The differences between low and high sensitivity group suggest that high sensitivity of walking speed to applied resistive force is indicative of overall weakness. INTERPRETATION: Individuals with high sensitivity to horizontal resistive force may be walking at or near their maximum force generating capacity when at comfortable walking speed, while low sensitivity individuals may have greater reserve force generating capacity when walking at a particular comfortable walking speed.

Biomechanical deficiencies in women with semitendinosus-gracilis anterior cruciate ligament reconstruction during drop jumps.

OBJECTIVE: To compare landing mechanics and neuromuscular recruitment strategies between women with semitendinosus-gracilis anterior cruciate ligament reconstruction (SG-ACLr) and noninjured women during double- and single-legged drop jumps. DESIGN: Cross-sectional biomechanical study. SETTING: Single university-based biomechanics laboratory. PARTICIPANTS: Fourteen women 1-5 years post-SG-ACLr and 16 noninjured women participated in this study. METHODS: After anthropometric measurements, warm-up, and familiarization procedures, participants performed 5 trials of a double- and single-legged drop jumps. MAIN OUTCOME MEASUREMENTS: Dynamic knee valgus was measured as the distance between knee joints during the landing phase of the double-leg drop jumps. Medial knee displacement was the outcome considered during the landing phase of the single-leg drop jumps. For both drop jump tasks, neuromuscular recruitment was evaluated through rectified normalized electromyographic activity of the quadriceps and hamstrings (amplitude and latency), and quadriceps/hamstrings electromyographic co-contraction ratio. RESULTS: Although the SG-ACLr group demonstrated a tendency toward a greater dynamic knee valgus during both drop jumps, these differences did not reach statistical significance. EMG data revealed different neuromuscular strategies for each group, depending on the specific jump. CONCLUSIONS: These findings suggest that women with SG-ACLr have a tendency toward greater dynamic knee valgus that could predispose to additional knee injuries. Rehabilitation specialists need to be aware of existing kinematic and neuromuscular deficiencies years after SG-ACLr. Taking this into consideration will aid in prescribing appropriate interventions designed to prevent re-injury.

Maximum walking speeds obtained using treadmill and overground robot system in persons with post-stroke hemiplegia.

BACKGROUND: Previous studies demonstrated that stroke survivors have a limited capacity to increase their walking speeds beyond their self-selected maximum walking speed (SMWS). The purpose of this study was to determine the capacity of stroke survivors to reach faster speeds than their SMWS while walking on a treadmill belt or while being pushed by a robotic system (i.e. "push mode"). METHODS: Eighteen chronic stroke survivors with hemiplegia were involved in the study. We calculated their self-selected comfortable walking speed (SCWS) and SMWS overground using a 5-meter walk test (5-MWT). Then, they were exposed to walking at increased speeds, on a treadmill and while in "push mode" in an overground robotic device, the KineAssist, until they were tested at a speed that they could not sustain without losing balance. We recorded the time and number of steps during each trial and calculated gait speed, average cadence and average step length. RESULTS: Maximum walking speed in the "push mode" was 13% higher than the maximum walking speed on the treadmill and both were higher ("push mode": 61%; treadmill: 40%) than the maximum walking speed overground. Subjects achieved these faster speeds by initially increasing both step length and cadence and, once individuals stopped increasing their step length, by only increasing cadence. CONCLUSIONS: With post-stroke hemiplegia, individuals are able to walk at faster speeds than their SMWS overground, when provided with a safe environment that provides external forces that requires them to attempt dynamic stability maintenance at higher gait speeds. Therefore, this study suggests the possibility that, given the appropriate conditions, people post-stroke can be trained at higher speeds than previously attempted.