IU Indianapolis ScholarWorks :: Browsing by Author "Hornby, T. George"

Browsing by Author "Hornby, T. George"

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Altered Sagittal- and Frontal-Plane Kinematics Following High-Intensity Stepping Training Versus Conventional Interventions in Subacute Stroke
(Oxford, 2016) Mahtani, Gordhan B.; Kinnaird, Catherine R.; Connolly, Mark; Holleran, Carey L.; Hennessy, Patrick W.; Woodward, Jane; Brazg, Gabrielle; Roth, Elliot J.; Hornby, T. George; Physical Medicine and Rehabilitation, School of Medicine
Background Common locomotor deficits observed in people poststroke include decreased speeds and abnormal kinematics, characterized by altered symmetry, reduced sagittal-plane joint excursions, and use of compensatory frontal-plane behaviors during the swing phase of gait. Conventional interventions utilized to mitigate these deficits often incorporate low-intensity, impairment-based or functional exercises focused on normalizing kinematics, although the efficacy of these strategies is unclear. Conversely, higher-intensity training protocols that provide only stepping practice and do not focus on kinematics have demonstrated gains in walking function, although minimal attention toward gait quality may be concerning and has not been assessed. Objective The present study evaluated changes in spatiotemporal and joint kinematics following experimental, high-intensity stepping training compared with conventional interventions. Design Kinematic data were combined from a randomized controlled trial comparing experimental and conventional training and from a pilot experimental training study. Methods Individuals with gait deficits 1 to 6 months poststroke received up to 40 sessions of either high-intensity stepping training in variable contexts or conventional lower-intensity interventions. Analyses focused on kinematic changes during graded treadmill testing before and following training. Results Significant improvements in speed, symmetry, and selected sagittal-plane kinematics favored experimental training over conventional training, although increases in compensatory strategies also were observed. Changes in many kinematic patterns were correlated with speed changes, and increased compensatory behaviors were associated with both stride length gains and baseline impairments. Limitations Limitations include a small sample size and use of multiple statistical comparisons. Conclusions Improved speeds and selected kinematics were observed following high-intensity training, although such training also resulted in increased use of compensatory strategies. Future studies should explore the consequences of utilizing these compensatory strategies despite the observed functional gains.
Applying the Knowledge-to-Action Framework to Implement Gait and Balance Assessments in Inpatient Stroke Rehabilitation
(Elsevier, 2020-11) Moore, Jennifer L.; Virva, Roberta; Henderson, Chris; Lenca, Lauren; Butzer, John F.; Lovell, Linda; Roth, Elliot; Graham, Ian D.; Hornby, T. George; Physical Medicine and Rehabilitation, School of Medicine
Objectives The overall objectives of this project were to implement and sustain use of a gait assessment battery (GAB) that included the Berg Balance Scale, 10-meter walk test, and 6-minute walk test during inpatient stroke rehabilitation. The study objective was to assess the effect of the study intervention on clinician adherence to the recommendations and its effect on clinician perceptions and the organization. Design Pre- and post-training intervention study. Setting Subacute inpatient rehabilitation facility. Participants Physical therapists (N=6) and physical therapist assistants (N=2). Intervention The intervention comprised a bundle of activities, including codeveloping and executing the plan with clinicians and leaders. The multicomponent implementation plan was based on the Knowledge-to-Action Framework and included implementation facilitation, implementation leadership, and a bundle of knowledge translation interventions that targeted barriers. Implementation was an iterative process in which results from one implementation phase informed planning of the next phase. Main Outcome Measures Clinician administration adherence, surveys of perceptions, and organizational outcomes. Results Initial adherence to the GAB was 46% and increased to more than 85% after 6 months. These adherence levels remained consistent 48 months after implementation. Clinician perceptions of measure use were initially high (>63%), with significant improvements in knowledge and use of one measure after implementation. Conclusions We successfully implemented the assessment battery with high levels of adherence to recommendations, likely because of using the bundle of knowledge translation activities, facilitation, and use of a framework to codevelop the plan. These changes in practice were sustainable, as determined by a 4-year follow-up.
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 Medicine
Background: 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.
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 Medicine
Background 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.
Development and Results of an Implementation Plan for High-Intensity Gait Training
(Wolters Kluwer, 2021) Moore, Jennifer L.; Bø, Elisabeth; Erichsen, Anne; Rosseland, Ingvild; Halvorsen, Joakim; Bratlie, Hanne; Hornby, T. George; Nordvik, Jan Egil; Physical Medicine and Rehabilitation, School of Medicine
Background and purpose: High-intensity gait training is recommended in stroke rehabilitation to improve gait speed, walking distance, and balance. However, identifying effective and efficient implementation methods is a challenge for rehabilitation providers. This article describes the development of an implementation plan, presents findings of each implementation phase, and identifies the project's impact on clinicians and the health system. Methods: Two inpatient rehabilitation facilities, including 9 physical therapists, collaborated with a knowledge translation center to implement this program. We developed an implementation plan using the Knowledge-to-Action Framework and utilized the Consolidated Framework for Implementation Research to identify barriers and select implementation strategies. Using mix-methods research, including surveys and informal discussions, we evaluated current practice, barriers, outcomes, and the sustainability of high-intensity gait training in practice. Results: A multicomponent implementation plan that targeted barriers was developed. Before implementation, clinicians reported providing several balance, strength training, and gait interventions to improve walking. Barriers to using high-intensity gait training included knowledge, beliefs, adaptability of high-intensity gait training, resources, culture, and others. Twenty-six implementation strategies were selected to target the barriers. Surveys and informal discussions identified significant changes in perceived practice, adoption of high-intensity gait training, and positive impacts on the health system. The 2-year follow-up survey indicated that the new practice was sustained. Discussion and conclusions: Using a multicomponent implementation plan that targeted barriers, we successfully implemented high-intensity gait training in clinical practice. Contributors to successful implementation may include the implementation methods, usual care interventions, and clinicians' readiness for this change. Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A352.).
Effect of Investigator Observation on Gait Parameters in Individuals with Stroke
(Elsevier, 2020-02-13) Ardestani, Marzieh M.; Hornby, T. George; Physical Medicine and Rehabilitation, School of Medicine
Improvements in gait speed following various training paradigms applied to patients post-stroke does not always lead to changes in walking performance, defined as gains in daily stepping activity. We hypothesized that testing conditions, specifically the presence of an observer, influences patient behaviors and resultant outcomes may overestimate their true walking capacity. This potential Hawthorne effect on spatiotemporal and biomechanical measures of locomotor function in individuals post-stroke has not been assessed previously. Fifteen ambulatory individuals with chronic stroke wore instrumented insoles and performed two separate normal-pace walking assessments, including unobserved conditions during which participants were unattended and unaware of data collection, and observed conditions with an investigator present. Gait analysis was conducted outside of a laboratory setting using instrumented insoles equipped with a 3D accelerometer and pressure sensors which captured the spatiotemporal kinematics, vertical ground reaction forces and foot acceleration. Data were compared using paired comparisons, with subsequent correlation and stepwise regression analyses to explore potential associations between Hawthorne-induced changes in walking strategies, gait speed and locomotor performance (daily stepping). Except for cadence, other measures of spatiotemporal parameters and swing kinematics (acceleration) were not significantly different between observed vs unobserved conditions. However, analyses of ground reaction forces revealed significantly greater paretic limb loading (Δ1st peak = 1.5 ± 1.6 N/kg Δ2nd peak = 1.4 ± 1.8 N/kg; p < 0.01) and increases in weight bearing symmetry (11-24%, p < 0.01) during observed vs unobserved conditions. This potential Hawthorne effect was greater in those with slower walking speeds and shorter stride lengths but was not related to daily stepping. The present findings suggest that biomechanical parameters of walking function may be related to the presence of an observer and highlight the need to separately measure locomotor capacity (gait speed) and performance (daily stepping).
Exercise-Induced Alterations in Sympathetic-Somatomotor Coupling in Incomplete Spinal Cord Injury
(Mary Ann Liebert, Inc., publishers, 2019-09-15) Onushko, Tanya; Mahtani, Gordhan B.; Brazg, Gabrielle; Hornby, T. George; Schmit, Brian D.; Physical Medicine and Rehabilitation, School of Medicine
The aim of this study was to understand how high- and low-intensity locomotor training (LT) affects sympathetic-somatomotor (SS) coupling in people with incomplete spinal cord injury (SCI). Proper coupling between sympathetic and somatomotor systems allows controlled regulation of cardiovascular responses to exercise. In people with SCI, altered connectivity between descending pathways and spinal segments impairs sympathetic and somatomotor coordination, which may have deleterious effects during exercise and limit rehabilitation outcomes. We postulated that high-intensity LT, which repeatedly engages SS systems, would alter SS coupling. Thirteen individuals (50 ± 7.2 years) with motor incomplete spinal cord injuries (American Spinal Injury Association Impairment Scale C or D; injury level >T6) participated in a locomotor treadmill training program. Patients were randomized into either a high-intensity (high-LT; 70–85% of maximum predicted heart rate; n = 6) group or a low-intensity (low-LT; 50–65% of maximum predicted heart rate; n = 7) group and completed up to 20 LT training sessions over 4–6 weeks, 3–5 days/week. Before and after taining, we tested SS coupling by eliciting reflexive sympathetic activity through a cold stimulation, noxious stimulation, and a mental math task while we measured tendon reflexes, blood pressure, and heart rate. Participants who completed high- versus low-LT exhibited significant decreases in reflex torques during triggered sympathetic activity (cold: −83 vs. 13%, p < 0.01; pain: −65 vs. 54%, p < 0.05; mental math: −43 vs. 41%; p < 0.05). Mean arterial pressure responses to sympathetic stimuli were slightly higher following high- versus low-LT (cold: 30 vs. −1.5%; pain: 6 vs. −12%; mental math: 5 vs. 7%), although differences were not statistically significant. These results suggest that high-LT may be advantageous to low-LT to improve SS coupling in people with incomplete SCI.
Gains in Daily Stepping Activity in People With Chronic Stroke After High-Intensity Gait Training in Variable Contexts
(Oxford University Press, 2022) Hornby, T. George; Plawecki, Abbey; Lotter, Jennifer K.; Scofield, Molly E.; Lucas, Emily; Henderson, Christopher E.; Physical Medicine and Rehabilitation, School of Medicine
Objective: Many physical therapist interventions provided to individuals with chronic stroke can lead to gains in gait speed or endurance (eg, 6-Minute Walk Test [6MWT]), although changes in objective measures of participation are not often observed. The goal of this study was to determine the influence of different walking interventions on daily stepping (steps per day) and the contributions of demographic, training, and clinical measures to these changes. Methods: In this secondary analysis of a randomized clinical trial, steps per day at baseline and changes in steps per day following 1 of 3 locomotor interventions were evaluated in individuals who were ambulatory and >6 months after stroke. Data were collected on 58 individuals who received ≤30 sessions of high-intensity training (HIT) in variable contexts (eg, tasks and environments; n = 19), HIT focused on forward walking (n = 19), or low-intensity variable training (n = 20). Primary outcomes were steps per day at baseline, at post-training, and at a 3-month follow-up, and secondary outcomes were gait speed, 6MWT, balance, and balance confidence. Correlation and regression analyses identified demographic and clinical variables associated with steps per day. Results: Gains in steps per day were observed across all groups combined, with no between-group differences; post hoc within-group analyses revealed significant gains only following HIT in variable contexts. Both HIT groups showed gains in endurance (6MWT), with increases in balance confidence only following HIT in variable contexts. Changes in steps per day were associated primarily with gains in 6MWT, with additional associations with baseline 6MWT, lower-extremity Fugl-Meyer scores, and changes in balance confidence. Conclusion: HIT in variable contexts elicited gains in daily stepping, with changes primarily associated with gains in gait endurance. Impact: Providing HIT in variable contexts appears to improve measures of participation (eg, daily stepping) that may be associated with clinical measures of function. Gains in multiple measures of mobility and participation with HIT in variable contexts may improve the efficiency and value of physical therapy services.
High intensity variable stepping training in persons with motor incomplete spinal cord injury: a case series
(Lippincott, Williams & Wilkins, 2020-04-05) Holleran, Carey L.; Hennessey, Patrick W.; Leddy, Abigail L.; Mahtani, Gordhan B.; Brazg, Gabrielle; Schmit, Brian D.; Hornby, T. George; Physical Medicine and Rehabilitation, School of Medicine
Background and Purpose: Previous data suggest that large amounts of high intensity stepping training in variable contexts (tasks and environments) may improve locomotor function, aerobic capacity and treadmill gait kinematics in individuals post-stroke. Whether similar training strategies are tolerated and efficacious for patients with other acute-onset neurological diagnoses, such as motor incomplete spinal cord injury (iSCI) is unknown, particularly with potentially greater, bilateral impairments. This case series evaluated the feasibility and preliminary short and long-term efficacy of high intensity variable stepping practice in ambulatory participants >1 year post-iSCI. Case Series Description: Four participants with iSCI (neurological levels C5-T3) completed up to 40 1-hr sessions over 3–4 months. Stepping training in variable contexts was performed at up to 85% maximum predicted heart rate, with feasibility measures of patient tolerance, total steps/session, and intensity of training. Clinical measures of locomotor function, balance, peak metabolic capacity and gait kinematics during graded treadmill assessments were performed at baseline and post-training, with >1 year follow-up. Outcomes: Participants completed 24–40 sessions over 8–15 weeks, averaging 2222±653 steps/session, with primary adverse events of fatigue and muscle soreness. Modest improvements in locomotor capacity where observed at post-training, with variable changes in lower extremity kinematics during treadmill walking. Discussion: High intensity, variable stepping training was feasible and tolerated by participants with iSCI although only modest gains in gait function or quality were observed. The utility of this intervention in patients with more profound impairments may be limited.
Immediate Adaptations to Post-Stroke Walking Performance Using a Wearable Robotic Exoskeleton
(Elsevier, 2019) Jayaraman, Arun; O'Brien, Megan K.; Madhavan, Sangeetha; Oikawa, Kiyoshi; Endo, Yosuke; Kantak, Shailesh; Stinear, James; Hornby, T. George; Rymer, William Zev; Physical Medicine and Rehabilitation, School of Medicine
Objective To examine the immediate effects of a hip-assistive wearable robotic exoskeleton on clinical walking performance, walking energetics, gait kinematics, and corticomotor excitability in individuals with stroke. Design Randomized cross-over trial. Setting Research laboratory of a rehabilitation hospital. Participants Twelve individuals (4F/8M, mean age 57.8±7.2) with chronic hemiparetic stroke. Interventions Honda’s Stride Management Assist (SMA) exoskeleton, which provides torque-based flexion and extension assistance at the hip joints during walking. Main Outcome Measures The primary outcome measure was change in self-selected walking speed with the device off vs. with the device on. Secondary outcome measures included changes in clinical endurance, energy expenditure, kinematics, and corticomotor excitability of lower limb muscles. Results In a single session using the device, participants exhibited adaptations over most outcome measures. Self-selected walking speed and peak treadmill speed increased, while oxygen consumption rate decreased during overground and treadmill endurance tests. More symmetric walking patterns were observed during treadmill walking. Changes in corticomotor excitability were highly variable among participants, with a non-significant increase in excitability for the paretic rectus femoris. Conclusions The SMA hip exoskeleton causes immediate positive adaptations in walking performance in individuals with stroke when the device is in use.

Browsing by Author "Hornby, T. George"

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