Effects of Training Intensity on Locomotor Performance in Individuals With Chronic Spinal Cord Injury: A Randomized Crossover Study

Background. Many physical interventions can improve locomotor function in individuals with motor incomplete spinal cord injury (iSCI), although the training parameters that maximize recovery are not clear. Previous studies in individuals with other neurologic injuries suggest the intensity of locomotor training (LT) may positively influence walking outcomes. However, the effects of intensity during training of individuals with iSCI have not been tested. Objective. The purpose of this pilot, blinded-assessor randomized trial was to evaluate the effects of LT intensity on walking outcomes in individuals with iSCI. Methods. Using a crossover design, ambulatory participants with iSCI \u3e1 year duration performed either high- or low-intensity LT for ≤20 sessions over 4 to 6 weeks. Four weeks following completion, the training interventions were alternated. Targeted intensities focused on achieving specific ranges of heart rate (HR) or ratings of perceived exertion (RPE), with intensity manipulated by increasing speeds or applying loads. Results. Significantly greater increases in peak treadmill speeds (0.18 vs 0.02 m/s) and secondary measures of metabolic function and overground speed were observed following high- versus low-intensity training, with no effects of intervention order. Moderate to high correlations were observed between differences in walking speed or distances and differences in HRs or RPEs during high- versus low-intensity training. Conclusion. This pilot study provides the first evidence that the intensity of stepping practice may be an important determinant of LT outcomes in individuals with iSCI. Whether such training is feasible in larger patient populations and contributes to improved locomotor outcomes deserves further consideration

Implementation of wearable sensing technology for movement: Pushing forward into the routine physical rehabilitation care field

While the promise of wearable sensor technology to transform physical rehabilitation has been around for a number of years, the reality is that wearable sensor technology for the measurement of human movement has remained largely confined to rehabilitation research labs with limited ventures into clinical practice. The purposes of this paper are to: (1) discuss the major barriers in clinical practice and available wearable sensing technology; (2) propose benchmarks for wearable device systems that would make it feasible to implement them in clinical practice across the world and (3) evaluate a current wearable device system against the benchmarks as an example. If we can overcome the barriers and achieve the benchmarks collectively, the field of rehabilitation will move forward towards better movement interventions that produce improved function not just in the clinic or lab, but out in peoples\u27 homes and communities

High intensity variable stepping training in persons with motor incomplete spinal cord injury: a case series

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

Stepwise Regression and Latent Profile Analyses of Locomotor Outcomes Poststroke

Background and purpose: Previous data suggest patient demographics and clinical presentation are primary predictors of motor recovery poststroke, with minimal contributions of physical interventions. Other studies indicate consistent associations between the amount and intensity of stepping practice with locomotor outcomes. The goal of this study was to determine the relative contributions of these combined variables to locomotor outcomes poststroke across a range of patient demographics and baseline function. Methods: Data were pooled from 3 separate trials evaluating the efficacy of high-intensity training, low-intensity training, and conventional interventions. Demographics, clinical characteristics, and training activities from 144 participants >1-month poststroke were included in stepwise regression analyses to determine their relative contributions to locomotor outcomes. Subsequent latent profile analyses evaluated differences in classes of participants based on their responses to interventions. Results: Stepwise regressions indicate primary contributions of stepping activity on locomotor outcomes, with additional influences of age, duration poststroke, and baseline function. Latent profile analyses revealed 2 main classes of outcomes, with the largest gains in those who received high-intensity training and achieved the greatest amounts of stepping practice. Regression and latent profile analyses of only high-intensity training participants indicated age, baseline function, and training activities were primary determinants of locomotor gains. Participants with the smallest gains were older (≈60 years), presented with slower gait speeds (<0.40 m/s), and performed 600 to 1000 less steps/session. Conclusions: Regression and cluster analyses reveal primary contributions of training interventions on mobility outcomes in patients >1-month poststroke. Age, duration poststroke, and baseline impairments were secondary predictors

Intensive Goal-Directed Treatments in Enriched Environments Augments Patient Outcomes Post-Stroke

Objective: Previous research indicates that patients post-stroke, average 400-800 steps within physical therapy sessions and demonstrate heart rate values of 24-35% of HR Max. This dosage and intensity is inadequate to promote neuroplastic changes and maximize recovery. The goal of this study was to quantify and examine the amount of high-intensity stepping practice that was delivered within an Acute Inpatient Rehabilitation (AIR) setting for individuals with sub-acute stroke. Methods: 14 patients with a diagnosis of sub-acute stroke were admitted to AIR. Standardized outcomes included the 6-Minute Walk Test (6MWT), 10-Meter Walk Test (10MWT), the Berg Balance Scale (BBS) and the Postural Assessment Scale for Stroke Patients (PASS). A step activity monitor with an internal accelerometer was applied on the non-paretic extremity from the hours of 7 am to 5 pm. During therapy sessions, subjects were exposed to a plan of care that involved high-intensity, high-frequency stepping practice through Body Weight Supported Treadmill Training (BWSTT), over-ground stepping, stair climbing, obstacle navigation, dynamic standing balance activities and error augmentation tasks. All individuals were continuously monitored with heart rate monitors, and perceived intensity was recorded within 5-minute intervals and after modification of activity with the Borg Rate of Perceived Exertion (RPE) Scale. Target intensity was defined with heart rate values of 70-85% of HR Max and RPE values of 14-20 (hard to maximal exertion). Time spent in target intensity ranges was collected. Each subject was scheduled for 1-2 hours of physical therapy per day. Results: During the 2-month collection period, subjects demonstrated ability to tolerate a high-intensity, high-frequency stepping gait training program within the intensities defined. Stepping data indicated that subjects received an average daily stepping dosage of 2000-8000 steps per day, well above previously reported values. Conclusion: It is possible to implement a high-intensity, high-frequency stepping gait training program within an acute inpatient rehabilitation setting for the stroke population. However, future research concerning therapy intensity and frequency of stepping should be designed with a larger sample size

Clinical Practice Guideline to Improve Locomotor Function Following Chronic Stroke, Incomplete Spinal Cord Injury, and Brain Injury

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

Altered Sagittal- and Frontal-Plane Kinematics Following High-Intensity Stepping Training Versus Conventional Interventions in Subacute Stroke

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