Browsing by Author "Henderson, Christopher E."
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Item Clinical Practice Guideline to Improve Locomotor Function Following Chronic Stroke, Incomplete Spinal Cord Injury, and Brain Injury(Wolters Kluwer, 2020-01) Hornby, T. George; Reisman, Darcy S.; Ward, Irene G.; Scheets, Patricia L.; Miller, Allison; Haddad, David; Fox, Emily J.; Fritz, Nora E.; Hawkins, Kelly; Henderson, Christopher E.; Hendron, Kathryn L.; Holleran, Carey L.; Lynskey, James E.; Walter, Amber; Physical Medicine and Rehabilitation, School of MedicineBackground: Individuals with acute-onset central nervous system (CNS) injury, including stroke, motor incomplete spinal cord injury, or traumatic brain injury, often experience lasting locomotor deficits, as quantified by decreases in gait speed and distance walked over a specific duration (timed distance). The goal of the present clinical practice guideline was to delineate the relative efficacy of various interventions to improve walking speed and timed distance in ambulatory individuals greater than 6 months following these specific diagnoses. Methods: A systematic review of the literature published between 1995 and 2016 was performed in 4 databases for randomized controlled clinical trials focused on these specific patient populations, at least 6 months postinjury and with specific outcomes of walking speed and timed distance. For all studies, specific parameters of training interventions including frequency, intensity, time, and type were detailed as possible. Recommendations were determined on the basis of the strength of the evidence and the potential harm, risks, or costs of providing a specific training paradigm, particularly when another intervention may be available and can provide greater benefit. Results: Strong evidence indicates that clinicians should offer walking training at moderate to high intensities or virtual reality–based training to ambulatory individuals greater than 6 months following acute-onset CNS injury to improve walking speed or distance. In contrast, weak evidence suggests that strength training, circuit (ie, combined) training or cycling training at moderate to high intensities, and virtual reality–based balance training may improve walking speed and distance in these patient groups. Finally, strong evidence suggests that body weight–supported treadmill training, robotic-assisted training, or sitting/standing balance training without virtual reality should not be performed to improve walking speed or distance in ambulatory individuals greater than 6 months following acute-onset CNS injury to improve walking speed or distance. Discussion: The collective findings suggest that large amounts of task-specific (ie, locomotor) practice may be critical for improvements in walking function, although only at higher cardiovascular intensities or with augmented feedback to increase patient's engagement. Lower-intensity walking interventions or impairment-based training strategies demonstrated equivocal or limited efficacy. Limitations: As walking speed and distance were primary outcomes, the research participants included in the studies walked without substantial physical assistance. This guideline may not apply to patients with limited ambulatory function, where provision of walking training may require substantial physical assistance. Summary: The guideline suggests that task-specific walking training should be performed to improve walking speed and distance in those with acute-onset CNS injury although only at higher intensities or with augmented feedback. Future studies should clarify the potential utility of specific training parameters that lead to improved walking speed and distance in these populations in both chronic and subacute stages following injury. Disclaimer: These recommendations are intended as a guide for clinicians to optimize rehabilitation outcomes for persons with chronic stroke, incomplete spinal cord injury, and traumatic brain injury to improve walking speed and distance.Item Contributions of Stepping Intensity and Variability to Mobility in Individuals Poststroke(American Heart Association, 2019-08-22) Hornby, T. George; Henderson, Christopher E.; Plawecki, Abbey; Lucas, Emily; Lotter, Jennifer; Holthus, Molly; Brazg, Gabrielle; Fahey, Meghan; Woodward, Jane; Ardestani, Marzieh; Roth, Elliot J.; Physical Medicine and Rehabilitation, School of MedicineBackground and Purpose: The amount of task-specific stepping practice provided during rehabilitation post-stroke can influence locomotor recovery, and reflects one aspect of exercise “dose” that can affect the efficacy of specific interventions. Emerging data suggest that markedly increasing the intensity and variability of stepping practice may also be critical, although such strategies are discouraged during traditional rehabilitation. The goal of this study was to determine the individual and combined contributions of intensity and variability of stepping practice to improving walking speed and distance in individuals post-stroke. Methods: This Phase 2, randomized, blinded assessor clinical trial was performed between May 2015-November 2018. Individuals between 18-85 years old with hemiparesis post-stroke of >6 months duration were recruited. Of the 152 individuals screened, 97 were randomly assigned to 1 of 3 training groups, with 90 completing >10 sessions. Interventions consisted of either high intensity stepping (70-80% heart rate [HR] reserve) of variable, difficult stepping tasks (high-variable), high intensity stepping performing only forward walking (high-forward), and low intensity stepping in variable contexts at 30-40% HR reserve (low-variable). Participants received up to 30 sessions over 2 months, with testing at baseline, post-training and a 3-month follow-up. Primary outcomes included walking speeds and timed distance, with secondary measures of dynamic balance, transfers, spatiotemporal kinematics and metabolic measures. Results: All walking gains were significantly greater following either high-intensity group vs low-variable training (all p<0.001) with significant correlations with stepping amount and rate (r=0.48-60; p<0.01). Additional gains in spatiotemporal symmetry were observed with high-intensity training, and balance confidence increased only following high-variable training in individuals with severe impairments. Conclusion: High intensity stepping training resulted in greater improvements in walking ability and gait symmetry than low-intensity training in individuals with chronic stroke, with potential greater improvements in balance confidence.Item Kinematic and Neuromuscular Adaptations in Incomplete Spinal Cord Injury after High- versus Low-Intensity Locomotor Training(Mary Ann Liebert, 2019-05-28) Ardestani, Marzieh M.; Henderson, Christopher E.; Salehi, Seyed H.; Mahtani, Gordhan B.; Schmit, Brian D.; Hornby, T. George; Physical Medicine and Rehabilitation, School of MedicineRecent data demonstrate improved locomotion with high-intensity locomotor training (LT) in individuals with incomplete spinal cord injury (iSCI), although concerns remain regarding reinforcement of abnormal motor strategies. The present study evaluated the effects of LT intensity on kinematic and neuromuscular coordination in individuals with iSCI. Using a randomized, crossover design, participants with iSCI received up to 20 sessions of high-intensity LT, with attempts to achieve 70–85% of age-predicted maximum heart rate (HRmax), or low-intensity LT (50–65% HRmax), following which the other intervention was performed. Specific measures included spatiotemporal variables, sagittal-plane gait kinematics, and neuromuscular synergies from electromyographic (EMG) recordings. Correlation analyses were conducted to evaluate associations between variables. Significant improvements in sagittal-plane joint excursions and intralimb hip-knee coordination were observed following high- but not low-intensity LT when comparing peak treadmill (TM) speed before and after LT. Neuromuscular complexity (i.e., number of synergies to explain >90% of EMG variance) was also increased following high- but not low-intensity LT. Comparison of speed-matched trials confirmed significant improvements in the knee excursion of the less impaired limb and intralimb hip-knee coordination, as well as improvements in neuromuscular complexity following high-intensity LT. These findings suggest greater neuromuscular complexity may be due to LT and not necessarily differences in speeds. Only selected kinematic changes (i.e., weak hip excursion) was correlated to improvements in treadmill speed. In conclusion, LT intensity can facilitate gains in kinematic variables and neuromuscular synergies in individuals with iSCI.Item Locomotor Kinematics and Kinetics Following High-Intensity Stepping Training in Variable Contexts Poststroke(SAGE, 2020-06-06) Ardestani, Marzieh M.; Henderson, Christopher E.; Mahtani, Gordhan; Connolly, Mark; Hornby, T. George; Physical Medicine and Rehabilitation, School of MedicineBackground and Purpose Previous studies suggest individuals post-stroke can achieve substantial gains in walking function following high-intensity locomotor training (LT). Recent findings also indicate practice of variable stepping tasks targeting locomotor deficits can mitigate selected impairments underlying reduced walking speeds. The goal of this study was to investigate alterations in locomotor biomechanics following three different LT paradigms. Methods This secondary analysis of a randomized trial recruited individuals 18–85 years old and >6 months post-stroke. We compared changes in spatiotemporal, joint kinematics and kinetics following up to 30 sessions of high-intensity (>70% heart rate reserve [HRR]) LT of variable tasks targeting paretic limb and balance impairments (high-variable, HV), high-intensity LT focused only on forward walking (high-forward, HF), or low-intensity LT (<40% HRR) of variable tasks (low-variable, LV). Sagittal spatiotemporal and joint kinematics, and concentric joint powers were compared between groups. Regressions and principle component (PC) analyses were conducted to evaluate relative contributions or importance of biomechanical changes to between and within groups. Results Biomechanical data were available on 50 participants who could walk ≥0.1 m/s on a motorized treadmill. Significant differences in spatiotemporal parameters, kinematic consistency, and kinetics were observed between HV and HF vs LV. Resultant PC analyses were characterized by paretic powers and kinematic consistency following HV, while HF and LV were characterized by non-paretic powers. Conclusion High-intensity LT results in greater changes in kinematics and kinetics as compared to lower-intensity interventions. The results may suggest greater paretic-limb contributions with high-intensity variable stepping training that targets specific biomechanical deficits.Item Predicting Discharge Walking Function With High-Intensity Stepping Training During Inpatient Rehabilitation in Nonambulatory Patients Poststroke(Elsevier, 2020) Henderson, Christopher E.; Fahey, Megan; Brazg, Gabi; Moore, Jennifer L.; Hornby, T. George; Physical Medicine and Rehabilitation, School of MedicineObjective This cohort investigation identified primary predictors of discharge walking function of nonambulatory individuals poststroke with high-intensity training (HIT) during inpatient rehabilitation. Design Observational cohort investigation. Setting Inpatient rehabilitation. Participants Data were collected from individuals (N=257) <6 months poststroke who required assistance to walk at admission. Intervention Clinical physical therapy interventions attempted to maximize stepping practice at higher intensities. Main Outcome Measures Primary outcomes included the discharge level of assistance required during walking (minimal or no assistance) and attainment of specific gait speed thresholds (0.4 and 0.8 m/s) during the 10-m walk test. Independent predictors were demographics, training interventions (including steps/day), baseline Berg Balance Scale (BBS), and paretic leg strength. Results Participants performed a median (interquartile range) of 1270 (533-2297) steps per day throughout inpatient rehabilitation, with significant differences between those who walked with versus without assistance at discharge. Logistic regressions indicate steps per day was a primary predictor of unassisted walking recovery; removal of steps per day resulted in primary predictors of baseline BBS and strength. Receiver operating characteristic (ROC) analyses indicate significant areas under the curve for BBS and relatively low cutoff scores of 5.5 points at admission to walk without assistance at any speed. ROC analyses performed using 1-week outcomes indicate BBS scores of 5-17 points were needed to achieve locomotor thresholds. Conclusion Stepping activity, BBS, and paretic leg strength were primary predictors of walking outcomes in patients performing HIT, and ROC analyses indicated recovery of independent walking could be achieved in low functioning patients early poststroke.Item Task-Specific Versus Impairment-Based Training on Locomotor Performance in Individuals With Chronic Spinal Cord Injury: A Randomized Crossover Study(SAGE, 2020-06-01) Lotter, Jennifer K.; Henderson, Christopher E.; Plawecki, Abbey; Holthus, Molly E.; Lucas, Emily H.; Ardestani, Marzieh M.; Schmit, Brian D.; Hornby, T. George; Physical Medicine and Rehabilitation, School of MedicineBackground: Many research studies attempting to improve locomotor function following motor incomplete spinal cord injury (iSCI) focus on providing stepping practice. However, observational studies of physical therapy strategies suggest the amount of stepping practice during clinical rehabilitation is limited; rather, many interventions focus on mitigating impairments underlying walking dysfunction. Objective: The purpose of this blinded-assessor randomized trial was to evaluate the effects of task-specific vs impairment-based interventions on walking outcomes in individuals with iSCI. Methods: Using a crossover design, ambulatory participants with iSCI > 1-year duration performed either task-specific (upright stepping) or impairment-based training for up to 20 sessions over ≤6 weeks, with interventions alternated after >4 weeks delay. Both strategies focused on achieving higher cardiovascular intensities, with training specificity manipulated by practicing only stepping practice in variable contexts or practicing impairment-based tasks targeting impairments underlying locomotor dysfunction (strengthening, balance tasks, and recumbent stepping). Results: Significantly greater increases in fastest overground and treadmill walking speeds were observed following task-specific vs impairment-based training, with moderate associations between differences in amount of practice and outcomes. Gains in balance confidence were also observed following task-specific vs impairment-based training, although incidence of falls was also increased with the former protocol. Limited gains were observed with impairment-based training except for peak power during recumbent stepping tests. Conclusion: The present study reinforces work from other patient populations that the specificity of task practice is a critical determinant of locomotor outcomes and suggest impairment-based exercises may not translate to improvements in functional tasks.