Overground Locomotor Training Research Articles

Dynamic Postural Stability Among Individuals With Parkinson's Disease Following Performance-Based Overground Locomotor Training

Individuals with Parkinson’s disease (PD) exhibit compromised dynamic postural stability with impaired gait and balance, which contribute to walking limitations. Performing turns while walking perturbs mediolateral stability, challenges the daily functioning of people with PD, and is attributed to altered thoracic movement patterns that include reducing peak turn velocity (°/s). Although previous studies in our lab demonstrated that individuals with neurological impairments improved walking capacity following performance-based overground locomotor training (OLT), dynamic postural stability changes following OLT in people with PD remain unknown. PURPOSE: Characterize changes in dynamic postural stability during turns while walking among individuals with PD following OLT, evidenced by peak turn velocity change. METHODS: Twelve participants with PD (7 Male / 5 Female; Age: 68.5 ± 6.4 years; Hoehn and Yahr: 1-3) completed 24 60-minute OLT sessions twice-weekly. Baseline (PRE) and follow-up (POST) assessments included the 10-minute walk test (10MWT) indoors along a 60-meter corridor while wearing inertial sensors around the fourth lumbar vertebra and the sternum. Angular velocity was collected from each sensor and processed offline. First, turns were identified using integrated lumbar data and extracted from the sternum sensor. Next, peak turn velocity was averaged across all turns at PRE and POST, respectively. Finally, the mean peak turn velocity changes were calculated in the frontal (PTVF) and transverse (PTVT) planes of motion. Positive (+) change reflects improved dynamic postural stability during turns. Statistical analysis included one-tailed t-tests and Cohen’s d effect size. RESULTS: Completed turns increased after OLT (+1.5 ± 1.51; p < 0.01). PTVF showed a moderate and significant increase following OLT (+1.59 ± 2.18 °/s; 95%CI: 0.20, 2.98; p = 0.014; Cohen’s d = 0.43) while PTVT change was small and not significant (+0.88 ± 3.18 °/s; 95%CI: -2.90, 1.14; p = 0.179; Cohen’s d = 0.25). CONCLUSION: This study provides preliminary evidence suggesting that participants moderately improved frontal plane dynamic postural stability during turns after OLT by adapting thoracic movement patterns in ways that likely attenuated perturbed mediolateral stability.

Effect of repeated locomotor training on ventilatory measures, perceived exertion and walking endurance in persons with motor incomplete spinal cord injury.

Pre-Post, Repeated Measures. To determine if a warm-up bout of exercise could elicit a phasic ventilatory response to constant work rate (CWR) exercise in individuals with incomplete spinal cord injury (iSCI) during unsupported CWR treadmill walking. Describe the changes in ventilatory kinetics, ventilatory variability and ratings of perceived exertion (RPE) before and after 12 and 24 weeks of overground locomotor training (OLT). Investigate the relationship among minute ventilation (VE) variability, RPE, and walking endurance. Laboratory. A 6-min CWR was used as a warm-up preceding a CWR, at the same walking speed, until volitional fatigue or 30 min. Breath-by-breath ventilatory data were examined during the second CWR using a mono-exponential model. VE variability was calculated as the difference between the observed and predicted values. Data were time-matched before and after 12 and 24 weeks of OLT. A Pearson's correlation was used for VE variability, RPE, and walking endurance. A warm-up CWR did elicit a phasic ventilatory response. OLT resulted in faster ventilatory kinetics. Ventilatory variability reduced after 12 weeks of OLT but returned to pre-OLT values after 24 weeks of training. The change in VE variability was correlated with the change in RPE throughout the study. 12 and 24 weeks of OLT resulted in significant improvements in treadmill walking time. SCI patients can achieve a phasic ventilatory response to walking if the exercise bout is preceded by a warm-up. OLT normalizes the ventilatory kinetics and improves walking endurance. The change in VE variability is correlated to RPE.

Walking endurance, muscle oxygen extraction, and perceived fatigability after overground locomotor training in incomplete spinal cord injury: A pilot study

Objective: The purpose of this study was to examine the effects of overground locomotor training (OLT) on walking endurance and gastrocnemius oxygen extraction in people with chronic cervical motor-incomplete spinal cord injury (SCI). Design: Prospective single-arm pre–post pilot study. Setting: Human Performance Research Laboratory. Participants: Adult men with traumatic chronic cervical SCI (n = 6; age = 30.8 ± 12.5). Intervention: Twenty-four sessions of structured OLT. Outcome measures: Walking endurance was determined during a constant work-rate time-to-exhaustion treadmill test. Normalized perceived fatigability was calculated by dividing subjective ratings of tiredness by walking time. Cardiorespiratory outcomes and muscle oxygen extraction were analyzed using breath-by-breath gas-exchange and near-infrared spectroscopy. Results: OLT resulted in large effects on walking endurance (1232 ± 446 s vs 1645 ± 255 s; d = 1.1; P = 0.045) and normalized perceived fatigability (5.3 ± 1.5 a.u. vs 3.6 ± 0.9 a.u.; d = 1.3; P = 0.033). Small-to-medium effects on absolute (2.8 ± 2.5 a.u. vs 4.2 ± 3.5 a.u.; d = 0.42; P = 0.035) and isotime (2.8 ± 2.5 a.u. vs 3.8 ± 3.0 a.u.; d = 0.33; P = 0.023) muscle oxygen extraction were also observed after OLT. Conclusion: These findings provide preliminary data supporting the potential for improved walking endurance, enhanced muscle O2 extraction, and reduced perceived fatigability in people with chronic cervical motor-incomplete SCI following the OLT program described in this study.

Overground Locomotor Training In Parkinson's Disease: Effects On Walking Economy And Performance Fatigability

Walking economy (WE) is a measure of metabolic energy expenditure relative to walking speed, and, when elevated, may contribute to decreased capacity and performance relative to sustained walking in people with Parkinson’s Disease (PD). Coupled with performance fatigability (PF), these factors may increase disability in this population. Although sustained walking underlies many daily activities and impacts physical activity for many people with PD, responses to walking-specific interventions to develop optimal training methods have not been fully investigated in this population. PURPOSE: Determine changes in WE, PF, and physiologic response during sustained walking following a task-specific, performance-based overground locomotor training program (OLT) in people with mild/moderate PD. METHODS: 7 males and 2 females (68.9 ± 7.1 years old, H&Y scores 1-3) completed a 12-week program of 24 OLT sessions lasting 45 - 60 minutes each. Subjects were coached through multiplanar movement drills based on components of the gait cycle emphasizing power, stability and stepping under aerobically challenging conditions (ClinicalTrials.gov. - NCT03864393). Walking performance was measured during an overground 10-minute walk test (10MWT) by total distance (TD) and PF (Δ speed/total distance). During the final 5 minutes of the 10MWT, average heart rate (HR), oxygen consumption (V̇O2), and carbon dioxide production (V̇CO2) were recorded using a portable metabolic system. These values were divided by the average speed in the final 5 minutes of the 10MWT to assess WE and physiologic response. RESULTS: There were moderate to large, significant effects for TD (925.77 ± 175.67 vs 1018.37 ± 133.83, p=0.019, d=0.59), PFS (1.11 ± 0.19 vs 0.98 ± 0.13, p=0.013, d=0.79) and HR/speed (76.46 ± 7.69 vs 71.49 ± 6.71 bpm/m/s, p=0.05, d=0.69). There were small, non-significant effects for V̇O2/speed (12.14 ± 1.99 vs 11.47 ± 2.89 mL/min/kg/m/s, d=0.34) and V̇CO2/speed (790.56 ± 196.8 vs 778.93 ± 197.94 mL/min/m/s, d=0.06). CONCLUSIONS: OLT improved WE and PFS during sustained walking. Despite a moderate effect, HR changes in response to OLT are difficult to interpret without additional measures of cardiorespiratory function. Larger and more mechanistic studies can provide further insight into this potential adaptation.

The Influence Of Overground Locomotor Training Program On Dynamic Balance In People With Parkinson’s Disease

The Influence Of Overground Locomotor Training Program On Dynamic Balance In People With Parkinson’s Disease

Effect of overground locomotor training on ventilatory kinetics and rate of perceived exertion in persons with cervical motor-incomplete spinal cord injury.

Study designPre-post, pilot study.ObjectivesTo characterize ventilatory (VE) responses to exercise following warm-up walking in individuals with chronic incomplete spinal cord injury (iSCI) during constant work rate (CWR) exercise. Secondarily, to investigate VE and tidal volume (VT) variability, and ratings of perceived exertion (RPE) before and after overground locomotor training (OLT).SettingResearch laboratory.MethodsA 6-min CWR walking bout at preferred pace was used as a warm-up followed by 6 min of rest and a second 6-min CWR bout at above preferred walking pace. The second CWR bout was analyzed. Breath-by-breath ventilatory data were examined using a curvilinear least squares fitting procedure with a mono-exponential model. VE and VT variability was calculated as the difference between the observed and predicted values and RPE was taken every 2 min.ResultsParticipants (n = 3, C4–C5) achieved a hyperpneic response to exercise in VE and VT. OLT resulted in faster ventilatory kinetics and reductions of 24 and 29% for VE and VT variability, respectively. A 30% reduction in RPE was concurrent with the reductions in ventilatory variability.ConclusionsOLT may improve ventilatory control during CWR in patients with cervical motor-iSCI. These data suggest that in some participants with iSCI, ventilation may influence RPE during walking. Future research should investigate mechanisms of ventilatory variability and its implications in walking performance in patients with iSCI.

Effects of Performance-Based Training on Gait and Balance in Individuals With Incomplete Spinal Cord Injury

ObjectiveTo determine changes in balance and gait following a task-specific, performance-based training protocol for overground locomotor training (OLT) in individuals with motor-incomplete spinal cord injury (iSCI). DesignConvenience sample, prepilot and postpilot study. SettingHuman performance research laboratory. ParticipantsAdults (N=15; 12 men and 3 women; mean age [y] ± SD, 41.5±16.9), American Spinal Injury Association Impairment Scale C or D, >6 months post-spinal cord injury. InterventionsTwo 90-minute OLT sessions per week over 12 to 15 weeks. OLT sessions were built on 3 principles of motor learning: practice variability, task specificity, and progressive overload (movement complexity, resistance, velocity, volume). Training used only voluntary movements without body-weight support, robotics, electrical stimulation, or bracing. Subjects used ambulatory assistive devices as necessary. Main Outcome MeasuresBerg Balance Scale (BBS), Spinal Cord Injury Functional Ambulation Inventory (SCI-FAI) gait parameters, spatiotemporal measures of gait (step length, step width, percent stance, stance:swing ratio) from 7 participants who walked across a pressure-sensitive walkway. ResultsFourteen participants completed the OLT protocol and 1 participant completed 15 sessions due to scheduled surgery. The BBS scores showed a mean improvement of 4.53±4.09 (P<.001). SCI-FAI scores showed a mean increase of 2.47±3.44 (P=.01). Spatiotemporal measures of gait showed no significant changes. ConclusionThis pilot demonstrated improvements in balance and selected gait characteristics using a task-specific, performance-based OLT for chronic iSCI.

Overground Locomotor Training Duration on Cardiorespiratory Adaptations in Incomplete Spinal Cord Injury

Overground Locomotor Training Duration on Cardiorespiratory Adaptations in Incomplete Spinal Cord Injury

Overground Locomotor Training in Incomplete Spinal Cord Injury

Overground Locomotor Training in Incomplete Spinal Cord Injury

EMG Analysis of Lower Limb Muscle Activation During 6-Minute Treadmill Walking Following Novel Over-Ground Locomotor Training in Incomplete Spinal Cord Injury

EMG Analysis of Lower Limb Muscle Activation During 6-Minute Treadmill Walking Following Novel Over-Ground Locomotor Training in Incomplete Spinal Cord Injury

Cardiorespiratory demand and rate of perceived exertion during overground walking with a robotic exoskeleton in long-term manual wheelchair users with chronic spinal cord injury: A cross-sectional study

BackgroundMany wheelchair users adopt a sedentary lifestyle, which results in progressive physical deconditioning with increased risk of musculoskeletal, cardiovascular and endocrine/metabolic morbidity and mortality. Engaging in a walking program with an overground robotic exoskeleton may be an effective strategy for mitigating these potential negative health consequences and optimizing fitness in this population. However, additional research is warranted to inform the development of adapted physical activity programs incorporating this technology. ObjectivesTo determine cardiorespiratory demands during sitting, standing and overground walking with a robotic exoskeleton and to verify whether such overground walking results in at least moderate-intensity physical exercise. MethodsWe enrolled 13 long-term wheelchair users with complete motor spinal cord injury in a walking program with an overground robotic exoskeleton. Cardiorespiratory measures and rate of perceived exertion (RPE) were recorded by using a portable gas analyzer system during sitting, standing and four 10m walking tasks with the robotic exoskeleton. Each participant also performed an arm crank ergometer test to determine maximal cardiorespiratory ability (i.e., peak heart rate and O2 uptake [HRpeak, VO2peak]). ResultsCardiorespiratory measures increased by a range of 9%–35% from sitting to standing and further increased by 22%–52% from standing to walking with the robotic exoskeleton. During walking, median oxygen cost (O2Walking), relative HR (%HRpeak), relative O2 consumption (%VO2peak) and respiratory exchange ratio (RER) reached 0.29mL/kg/m, 82.9%, 41.8% and 0.9, respectively, whereas median RPE reached 3.2/10. O2Walking was moderately influenced by total number of sessions and steps taken with the robotic exoskeleton since the start of the walking program. ConclusionOverground walking with the robotic exoskeleton over a short distance allowed wheelchair users to achieve a moderate-intensity level of exercise. Hence, an overground locomotor training program with a robotic exoskeleton may have cardiorespiratory health benefits in the population studied.

The Effect of Overground Locomotor Training on Walking Performance in Incomplete Spinal Cord Injured Patients

To report the repeated effects of overground locomotor training (OLT) on walking performance in incomplete spinal cord injury (iSCI).

Overground Locomotor Training in Spinal Cord Injury: A Performance-Based Framework.

Background: Locomotor training (LT) is the most commonly used treatment to improve walking performance following spinal cord injury (SCI). The advancement of LT treatments requires the addition of integrative models accounting for the numerous systems responsible for the recovery of walking function following SCI. Objective: This perspective monograph aims to (a) describe a performance-based framework for overground LT (OLT), (b) describe principles of adaptation and motor learning used to inform OLT program design, and (c) present an example OLT program based on the proposed framework. Methods: Individuals with chronic motor-incomplete SCI (7 male, 1 female) classified according to the American Spinal Injury Association Impairment Scale (AIS) as C and D were included. OLT included two 90-minute sessions performed over 12 weeks for a total of 24 sessions. Outcomes measures included overground walking speed, walking economy, pulmonary oxygen uptake, and muscle oxygen extraction measured via near-infrared spectroscopy. Results: Preliminary findings demonstrate the potential of OLT, as describe here, to increase overground walking speed, improve walking economy, accelerate processes associated with oxygen delivery and utilization at the rest-to-work transition, and lower oxygen extraction requirements of skeletal muscle during walking in individuals with chronic motor-incomplete SCI. Conclusion: The proposed framework offers a valuable template for LT program design in both clinical and research settings. Further research is necessary to better understand the effects of OLT and how principles of specificity, progressive overload, and variation within the performance-based framework can be manipulated to maximize function, health, and quality of life in SCI.

Effects of overground locomotor training on the ventilatory response to volitional treadmill walking in individuals with incomplete spinal cord injury: a pilot study.

Although there has been substantial emphasis on the neuromuscular and cardiovascular adaptations following rehabilitation, pulmonary adaptations in individuals with incomplete SCI (iSCI) in response to locomotor training have been less frequently studied. In healthy individuals, effective transition from rest to work is accomplished by a hyperpneic response, which exhibits an exponential curve with three phases. However, the degree to which our current understanding of exercise hyperpnea can be applied to individuals with iSCI is unknown. The purpose of this case series was to characterize exercise hyperpnea during a rest to constant work rate (CWR) transition before and after 12-15 weeks of overground locomotor training (OLT). Six subjects with cervical motor incomplete spinal cord injury participated in 12-15 weeks of OLT. Subjects were trained in 90-min sessions twice a week. All training activities were weight-bearing and under volitional control without the assistance of body-weight support harnesses, robotic devices or electrical stimulation. Six minutes of CWR treadmill walking was performed at self-selected pace with cardiorespiratory analysis throughout the tests before and after OLT. Averaged group data for tidal volume, breathing frequency or VE showed no difference before and after training. VE variability was decreased by 46.7% after OLT. CWR VE from rest to work was linear throughout the transition. Following OLT, there was a substantial reduction in VE variability. Future research should investigate the lack of a phasic ventilatory response to exercise, as well as potential mechanisms of ventilatory variability and its implications for functional performance.

Effects of Overground Locomotor Training on Walking Performance in Chronic Cervical Motor Incomplete Spinal Cord Injury: A Pilot Study

ObjectiveTo determine the effects of a novel overground locomotor training program on walking performance in people with chronic cervical motor incomplete spinal cord injury (iSCI). DesignBefore-after pilot study. SettingHuman performance research laboratory. ParticipantsAdults (N=6, age >18y) with chronic cervical iSCI with American Spinal Injury Association Impairment Scale grades C and D. InterventionsOverground locomotor training included two 90-minute sessions per week for 12 to 15 weeks. Training sessions alternated between uniplanar and multiplanar stepping patterns. Each session was comprised of 5 segments: joint mobility, volitional muscle activation, task isolation, task integration, and activity rehearsal. Main Outcome MeasuresOverground walking speed, oxygen consumption (V˙o2), and carbon dioxide production (V˙co2). ResultsOverground locomotor training increased overground walking speed (.36±.20 vs .51±.24 m/s, P<.001, d=.68). Significant decreases in V˙o2 (6.6±1.3 vs 5.7±1.4mL·kg·min, P=.038, d=.67) and V˙co2 (753.1±125.5 vs 670.7±120.3mL/min, P=.036, d=.67) during self-selected constant work rate treadmill walking were also noted after training. ConclusionsThe overground locomotor training program used in this pilot study is feasible and improved both overground walking speed and walking economy in a small sample of people with chronic cervical iSCI. Future studies are necessary to establish the efficacy of this overground locomotor training program and to differentiate among potential mechanisms contributing to enhanced walking performance in people with iSCI after overground locomotor training.

Locomotor-Respiratory Coupling During Treadmill Walking Before and After Overground Locomotor Training in Incomplete Spinal Cord Injury

Locomotor-Respiratory Coupling During Treadmill Walking Before and After Overground Locomotor Training in Incomplete Spinal Cord Injury

Effects of a Novel Overground Locomotor Training Program on Muscle Oxygen Extraction in Individuals with Incomplete Spinal Cord Injury

Effects of a Novel Overground Locomotor Training Program on Muscle Oxygen Extraction in Individuals with Incomplete Spinal Cord Injury

Does Exercise Tolerance Testing at 60 Days Poststroke Predict Rehabilitation Performance?

ObjectiveTo assess the relationship between exercise tolerance test (ETT) performance at 6 weeks poststroke and subsequent performance in a treadmill and overground locomotor training program (LTP). DesignProspective cohort study. SettingExercise testing laboratory in either a primary care hospital or outpatient clinic. ParticipantsCommunity-dwelling individuals (N=469), 54.9±19.0 days poststroke, enrolled in the Locomotor Experience Applied Post-Stroke randomized controlled trial. InterventionsNot applicable. Main Outcome MeasuresFor participants randomly assigned to LTP, the number of sessions needed to attain the training goal of 20 minutes of treadmill stepping was determined. Regression analyses determined the contribution of ETT performance (cycling duration), age, and 6-minute walk test (6MWT) distance to attainment of the stepping duration goal. ResultsAge, 6MWT, and ETT performance individually accounted for 10.74%, 10.82%, and 10.76%, respectively, of the variance in the number of sessions needed to attain 20 minutes of stepping. When age and 6MWT were included in the model, the additional contribution of ETT performance was rendered nonsignificant (P=.150). ConclusionsTo the extent that ETT performance can be viewed as a measure of cardiovascular fitness rather than neurologic impairment, cardiovascular fitness at the time of the ETT did not make a significant unique contribution to the number of sessions needed to achieve 20 minutes of stepping. The 6MWT, which involves less intensive exercise than the ETT and therefore is likely to be predominantly affected by neurologic impairment and muscular condition, appeared to account for as much variance as the ETT.

Over-ground and robotic-assisted locomotor training in adults with chronic stroke: a blinded randomized clinical trial

Purpose: The purpose was to compare the effectiveness of robotic-assisted body weight supported treadmill training using the Lokomat® to over-ground gait training (OGT) in adults with chronic stroke. Methods: Participants were randomly assigned to the Lokomat® or OGT interventions. Both protocols included 40 sessions over 8 weeks. Primary outcome measures were the 10-meter walk test and 6-minute walk distance. Secondary measures included the Functional Independence MeasureTM locomotion score, Fugl-Meyer Lower Extremity Motor Score (FM-LE), Barthel Index, and Stroke Impact Scale. Blinded assessors tested the participants at baseline, post-intervention, and 3-month follow-up. Results: Eleven Lokomat® and nine OGT participants completed the study. Within group differences in the FM-LE score and Barthel Index occurred over time from baseline to post-intervention and baseline to 3-month follow-up. No other within group differences and no between group differences were observed. Conclusions: Although walking measures did not show significant changes between groups, LE motor function and physical functional levels improved over time within both groups. The Lokomat® may allow aggressive locomotor training, particularly for the lower functioning patients who wish to improve walking ability due to apparent eased therapist physical burden, when compared to OGT, although an increased risk of skin breakdown is present.Implications for RehabilitationSurvivors of chronic stroke can continue to improve in motor recovery and functional ability after intensive over-ground or robotic-assisted locomotor training.Over-ground and robotic-assisted locomotor training appear to equivalently enhance motor recoveryand functional ability in low functioning survivors of chronic stroke.Risk of skin breakdown is significant with roboticassisted locomotor training.

The Recovery of Running Ability in an Adolescent Male After Traumatic Brain Injury: A Case Study

The purpose of this case study was to document outcomes after a rehabilitation program in an adolescent male after traumatic brain injury. Three years after sustaining an injury in a skiing accident, a 17-year-old boy participated in a rehabilitation program with the goal of acquiring the ability to run one mile with his peers. On initial evaluation, the individual had significant left lower extremity weakness, impaired standing balance, limited endurance, and running limitations. He was able to run 10 m wearing a plastic ankle-foot orthosis on the left side but required supervision for safety. The intervention included strength training once weekly for 17 weeks, body weight-supported, treadmill-based locomotor training once weekly for 15 weeks followed by a combination of overground locomotor training and strengthening exercise once weekly for six weeks. After the intervention, muscle strength of the lower extremities increased and the individual was able to run one mile independently. The quality of his running improved, with better mechanics to absorb forces at impact during the absorption phase and increased lower extremity extension during the propulsion phase. A rehabilitation program consisting of strengthening and locomotor training improved running speed, quality, and endurance in an adolescent male after traumatic brain injury. He was able to progress to a less restrictive carbon fiber brace as a result of gains in lower extremity strength. This change in ability allowed him to participate in physical education by running on a track and playing softball with his peers.