Carmen E. Capo-Lugo

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

BackgroundPrevious 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”).MethodsEighteen 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.ResultsMaximum 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.ConclusionsWith 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.

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.

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

BackgroundIndividuals post-stroke select slow comfortable walking speeds (CWS) and the major factors used to select their CWS is unknown.ObjectiveTo determine the extent to which slow CWS post-stroke is achieved through matching a relative force output or targeting a particular walking speed.MethodsTen 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.ResultsThe 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).ConclusionsThe 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.

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.

Reduced Functional and Quality of Life Outcomes Associated With Delays in Evaluation for Acute Rehabilitation Services

Objective(s): To assess the impact of delays in evaluation for rehabilitation services on disability and health-related quality of life (HRQoL) after ischemic stroke and transient ischemic attack (TIA). Design: Rehabilitation evaluations (i.e., PT: physical therapy; OT: occupational therapy) were obtained from a retrospective chart review and HRQoL measures from a longitudinal observational study of poststroke outcomes. Setting: Stroke Center provided rehabilitation-related data. Participants in the community provided HRQoL data. Participants: Individuals post-stroke (nZ420) who underwent physical or occupational therapy evaluations. The sample was on average 66.2 years old (SDZ15.7), was largely white (64.1%); 47.4% were female, and 13.3% had a TIA diagnosis. Interventions: Usual rehabilitation services. Main Outcome Measure(s): Modified Rankin Scale (mRS) at 1 and 3months post-stroke and Neurological Quality of Life (NeuroQoL) measures of upperand lower-extremity physical function, general cognitive concerns, and executive function. Results: The mean number of days between hospital admission to evaluation (i.e., delay) was 3.2 (SDZ2.9) for PT and 4.4 (SDZ4.5) for OT. After controlling for age, stroke severity and stroke subtype, each additional day of delay resulted in higher levels of disability (mRS: PT, bZ0.06, p<0.01; OT, bZ0.08, p<0.001) and additional decrements in physical function (Upper Extremity: OT, bZ-0.37, p<0.01; Lower Extremity: PT, bZ-0.47, p<0.05; OT, bZ-0.57, p<0.001) and cognitive function (Executive Function: PT, bZ-0.65, p<0.01; OT: bZ-0.84, p<0.001; General Concerns: PT, bZ-0.54, p<0.01; OT, bZ-0.47, p<0.001) at 1-month post-stroke. All effects were maintained at 3-months for OT only. Conclusions: Long-term disability after stroke is associated with delayed evaluation for rehabilitation services. In order to reduce long-term disability, early evaluation should be implemented, but the appropriate timing to initiate rehabilitation post-stroke is still unknown.