Guiding task-oriented gait training after stroke or spinal cord injury by means of a biomechanical gait analysis

Task-oriented training for gait rehabilitation in people with multiple sclerosis: A systematic review

OBJECTIVES

This systematic review aims to examine the effects of task-oriented (TO) training on gait function in people with multiple sclerosis (MS) and to determine the most effective TO training protocol.

METHODS

We searched PubMed, Web of Science, Scopus, EMBASE, REHABDATA, and PEDro for studies that examined the effects of TO on gait ability (i.e., gait velocity, gait endurance, functional mobility) in people with MS from 1971 to October 2022. The quality of the selected studies was estimated using the Physiotherapy Evidence Database (PEDro) scale.

RESULTS

Nine studies met the eligibility criteria. A total of 199 people with MS, 58.79% of whom were women, were included. Five studies revealed "good" quality, one revealed "fair", and three exhibited "poor" quality. Four studies administered TO training alone, and five combined TO training with conventional physiotherapy. The selected studies showed varied results for the influences of TO training on gait ability in people with MS.

CONCLUSIONS

The evidence for the impact of TO training on people with MS was limited. The optimal TO training protocol stills vague. Further studies with larger sample sizes are needed.

Gait Impairment Analysis Using Silhouette Sinogram Signals and Assisted Knowledge Learning

The analysis of body motion is a valuable tool in the assessment and diagnosis of gait impairments, particularly those related to neurological disorders. In this study, we propose a novel automated system leveraging artificial intelligence for efficiently analyzing gait impairment from video-recorded images. The proposed methodology encompasses three key aspects. First, we generate a novel one-dimensional representation of each silhouette image, termed a silhouette sinogram, by computing the distance and angle between the centroid and each detected boundary points. This process enables us to effectively utilize relative variations in motion at different angles to detect gait patterns. Second, a one-dimensional convolutional neural network (1D CNN) model is developed and trained by incorporating the consecutive silhouette sinogram signals of silhouette frames to capture spatiotemporal information via assisted knowledge learning. This process allows the network to capture a broader context and temporal dependencies within the gait cycle, enabling a more accurate diagnosis of gait abnormalities. This study conducts training and an evaluation utilizing the publicly accessible INIT GAIT database. Finally, two evaluation schemes are employed: one leveraging individual silhouette frames and the other operating at the subject level, utilizing a majority voting technique. The outcomes of the proposed method showed superior enhancements in gait impairment recognition, with overall F1-scores of 100%, 90.62%, and 77.32% when evaluated based on sinogram signals, and 100%, 100%, and 83.33% when evaluated based on the subject level, for cases involving two, four, and six gait abnormalities, respectively. In conclusion, by comparing the observed locomotor function to a conventional gait pattern often seen in healthy individuals, the recommended approach allows for a quantitative and non-invasive evaluation of locomotion.

Does Music Therapy Improve Gait after Traumatic Brain Injury and Spinal Cord Injury? A Mini Systematic Review and Meta-Analysis

There is a growing body of research examining the potential benefits of music therapy-based auditory stimulation (MT) for individuals with movement disorders in improving gait performance. However, there is limited knowledge about the effects of MT on gait outcomes in individuals with traumatic brain injury (TBI) or spinal cord injury (SCI). A previous review of MT's impact on gait in TBI had limitations, and there are no studies on its effects on gait in SCI. In this study, we conducted a meta-analysis to more thoroughly evaluate the impact of MT on gait outcomes in individuals with TBI and SCI. We systematically searched through eight databases and found six studies on MT in TBI and four on SCI. Our meta-analysis showed that MT has positive medium effect improvements on spatiotemporal aspects of gait in individuals with TBI (Hedge's g: 0.52) and SCI (0.53). These findings suggest that MT could be a practical intervention for enhancing different aspects of gait in these populations, although the limited number and "fair" quality of the studies included in the meta-analysis may affect the generalizability of the outcomes. Further research is needed to fully understand the mechanisms by which MT may influence gait and determine the optimal parameters for its use.

Effects of Task-Specific Training after Cognitive Sensorimotor Exercise on Proprioception, Spasticity, and Gait Speed in Stroke Patients: A Randomized Controlled Study

Background and objectives: Common problems in stroke patients include loss of proprioception, spasticity, and impaired gait. The purpose of this study was to examine the effects of task-specific training (TST) combined with cognitive sensorimotor exercise (CSE) on proprioception, spasticity and gait speed in stroke patients. Materials andMethods: Thirty-seven subjects were randomly divided into three groups; (1) the TST after CSE group (Experimental I, n = 13); (2) the TST group (Experimental II, n = 12), and (3) a conventional physical therapy training group (control group, n = 12). Evaluations were performed before the commencement of training and again eight weeks after training was initiated. An electrogoniometer was used to evaluate proprioception variation. The composite spasticity score (CSS) and MyotonePRO were used to evaluate spasticity. In addition, 10 m walk test was used to assess gait speed. Results: After training, the Experimental I group showed significant improvement in proprioception compared to the Experimental II and control group (p < 0.05). In CSS, gastrocnemius muscle tone (GMT) and gait speed among three groups, Experimental I group differed significantly after eight weeks of training compared to the control group (p < 0.05). Conclusions: These findings suggest that the TST combined with CSE provided significant improvements in proprioception, spasticity, and gait speed.

The Actuation System of the Ankle Exoskeleton T-FLEX: First Use Experimental Validation in People with Stroke

Robotic devices can provide physical assistance to people who have suffered neurological impairments such as stroke. Neurological disorders related to this condition induce abnormal gait patterns, which impede the independence to execute different Activities of Daily Living (ADLs). From the fundamental role of the ankle in walking, Powered Ankle-Foot Orthoses (PAFOs) have been developed to enhance the users’ gait patterns, and hence their quality of life. Ten patients who suffered a stroke used the actuation system of the T-FLEX exoskeleton triggered by an inertial sensor on the foot tip. The VICONmotion capture system recorded the users’ kinematics for unassisted and assisted gait modalities. Biomechanical analysis and usability assessment measured the performance of the system actuation for the participants in overground walking. The biomechanical assessment exhibited changes in the lower joints’ range of motion for 70% of the subjects. Moreover, the ankle kinematics showed a correlation with the variation of other movements analyzed. This variation had positive effects on 70% of the participants in at least one joint. The Gait Deviation Index (GDI) presented significant changes for 30% of the paretic limbs and 40% of the non-paretic, where the tendency was to decrease. The spatiotemporal parameters did not show significant variations between modalities, although users’ cadence had a decrease of 70% of the volunteers. Lastly, the satisfaction with the device was positive, the comfort being the most user-selected aspect. This article presents the assessment of the T-FLEX actuation system in people who suffered a stroke. Biomechanical results show improvement in the ankle kinematics and variations in the other joints. In general terms, GDI does not exhibit significant increases, and the Movement Analysis Profile (MAP) registers alterations for the assisted gait with the device. Future works should focus on assessing the full T-FLEX orthosis in a larger sample of patients, including a stage of training.

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.

An Initial Investigation of the Responsiveness of Temporal Gait Asymmetry to Rhythmic Auditory Stimulation and the Relationship to Rhythm Ability Following Stroke

Temporal gait asymmetry (TGA) is a persistent post-stroke gait deficit. Compared to conventional gait training techniques, rhythmic auditory stimulation (RAS; i.e., walking to a metronome) has demonstrated positive effects on post-stroke TGA. Responsiveness of TGA to RAS may be related to several factors including motor impairment, time post-stroke, and individual rhythm abilities. The purpose of this study was to investigate the relationship between rhythm abilities and responsiveness of TGA when walking to RAS. Assessed using behavioral tests of beat perception and production, participants with post-stroke TGA (measured as single limb support time ratio) were categorized according to rhythm ability (as strong or weak beat perceivers/producers). We assessed change in TGA between walking without cues (baseline) and walking while synchronizing footsteps with metronome cues. Most individuals with stroke were able to maintain or improve TGA with a single session of RAS. Within-group analyses revealed a difference between strong and weak rhythm ability groups. Strong beat perceivers and producers showed significant reduction (improvement) in TGA with the metronome. Those with weak ability did not and exhibited high variability in the TGA response to metronome. Moreover, individuals who worsened in TGA when walking to metronome had poorer beat production scores than those who did not change in TGA. However, no interaction between TGA improvement when walking to metronome and rhythm perception or production ability was found. While responsiveness of TGA to RAS did not significantly differ based on strength of rhythm abilities, these preliminary findings highlight rhythm ability as a potential consideration when treating post-stroke individuals with rhythm-based treatments.

Locomotor Kinematics and Kinetics Following High-Intensity Stepping Training in Variable Contexts Poststroke

Background and Purpose. Previous studies suggest that individuals poststroke 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 3 different LT paradigms. Methods. This secondary analysis of a randomized trial recruited individuals 18 to 85 years old and >6 months poststroke. 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 principal component 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 versus LV. Resultant principal component analyses were characterized by paretic powers and kinematic consistency following HV, while HF and LV were characterized by nonparetic powers. Conclusion. High-intensity LT results in greater changes in kinematics and kinetics as compared with lower-intensity interventions. The results may suggest greater paretic-limb contributions with high-intensity variable stepping training that targets specific biomechanical deficits. Clinical Trial Registration. https://clinicaltrials.gov/ Unique Identifier: NCT02507466.

Lower extremity outcome measures: considerations for clinical trials in spinal cord injury

STUDY DESIGN

This is a focused review article.

OBJECTIVES

To identify important concepts in lower extremity (LE) assessment with a focus on locomotor outcomes and provide guidance on how existing outcome measurement tools may be best used to assess experimental therapies in spinal cord injury (SCI). The emphasis lies on LE outcomes in individuals with complete and incomplete SCI in Phase II-III trials.

METHODS

This review includes a summary of topics discussed during a workshop focusing on LE function in SCI, conceptual discussion of corresponding outcome measures and additional focused literature review.

RESULTS

There are a number of sensitive, accurate, and responsive outcome tools measuring both quantitative and qualitative aspects of LE function. However, in trials with individuals with very acute injuries, a baseline assessment of the primary (or secondary) LE outcome measure is often not feasible.

CONCLUSION

There is no single outcome measure to assess all individuals with SCI that can be used to monitor changes in LE function regardless of severity and level of injury. Surrogate markers have to be used to assess LE function in individuals with severe SCI. However, it is generally agreed that a direct measurement of the performance for an appropriate functional activity supersedes any surrogate marker. LE assessments have to be refined so they can be used across all time points after SCI, regardless of the level or severity of spinal injury.

SPONSORS

Craig H. Neilsen Foundation, Spinal Cord Outcomes Partnership Endeavor.

Protocol for promoting recovery optimization of walking activity in stroke (PROWALKS): a randomized controlled trial

BACKGROUND

Stroke survivors are more physically inactive than even the most sedentary older adults, and low activity is associated with increased risk of recurrent stroke, medical complications, and mortality. We hypothesize that the combination of a fast walking intervention that improves walking capacity, with a step activity monitoring program that facilitates translation of gains from the clinic to the "real-world", would generate greater improvements in real world walking activity than with either intervention alone.

METHODS

Using a single-blind randomized controlled experimental design, 225 chronic (> 6 months) stroke survivors complete 12 weeks of fast walking training, a step activity monitoring program or a fast walking training + step activity monitoring program. Main eligibility criteria include: chronic ischemic or hemorrhagic stroke (> 6 months post), no evidence of cerebellar stroke, baseline walking speed between 0.3 m/s and 1.0 m/s, and baseline average steps / day < 8000. The primary (steps per day), secondary (self-selected and fastest walking speed, walking endurance, oxygen consumption) and exploratory (vascular events, blood lipids, glucose, blood pressure) outcomes are assessed prior to initiating treatment, after the last treatment and at a 6 and 12-month follow-up. Moderation of the changes in outcomes by baseline characteristics are evaluated to determine for whom the interventions are effective.

DISCUSSION

Following completion of this study, we will not only understand the efficacy of the interventions and the individuals for which they are effective, we will have the necessary information to design a study investigating the secondary prevention benefits of improved physical activity post-stroke. This study is, therefore, an important step in the development of both rehabilitative and secondary prevention guidelines for persons with stroke.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02835313 . First Posted: July 18, 2016.

Clinical-oriented Three-dimensional Gait Analysis Method for Evaluating Gait Disorder

Three-dimensional gait analysis (3DGA) is shown to be a useful clinical tool for the evaluation of gait abnormality due to movement disorders. However, the use of 3DGA in actual clinics remains uncommon. Possible reasons could include the time-consuming measurement process and difficulties in understanding measurement results, which are often presented using a large number of graphs. Here we present a clinician-friendly 3DGA method developed to facilitate the clinical use of 3DGA. This method consists of simplified preparation and measurement processes that can be performed in a short time period in clinical settings and intuitive results presentation to facilitate clinicians' understanding of results. The quick, simplified measurement procedure is achieved by the use of minimum markers and measurement of patients on a treadmill. To facilitate clinician understanding, results are presented in figures based on the clinicians' perspective. A Lissajous overview picture (LOP), which shows the trajectories of all markers from a holistic viewpoint, is used to facilitate intuitive understanding of gait patterns. Abnormal gait pattern indices, which are based on clinicians' perspectives in gait evaluation and standardized using the data of healthy subjects, are used to evaluate the extent of typical abnormal gait patterns in stroke patients. A graph depicting the analysis of the toe clearance strategy, which depicts how patients rely on normal and compensatory strategies to achieve toe clearance, is also presented. These methods could facilitate implementation of 3DGA in clinical settings and further encourage development of measurement strategies from the clinician's point of view.

Automatic recognition of gait patterns in human motor disorders using machine learning: A review

BACKGROUND

automatic recognition of human movement is an effective strategy to assess abnormal gait patterns. Machine learning approaches are mainly applied due to their ability to work with multidimensional nonlinear features.

PURPOSE

to compare several machine learning algorithms employed for gait pattern recognition in motor disorders using discriminant features extracted from gait dynamics. Additionally, this work highlights procedures that improve gait recognition performance.

METHODS

we conducted an electronic literature search on Web of Science, IEEE, and Scopus, using "human recognition", "gait patterns'', and "feature selection methods" as relevant keywords.

RESULTS

analysis of the literature showed that kernel principal component analysis and genetic algorithms are efficient at reducing dimensional features due to their ability to process nonlinear data and converge to global optimum. Comparative analysis of machine learning performance showed that support vector machines (SVMs) exhibited higher accuracy and proper generalization for new instances.

CONCLUSIONS

automatic recognition by combining dimensional data reduction, cross-validation and normalization techniques with SVMs may offer an objective and rapid tool for investigating the subject's clinical status. Future directions comprise the real-time application of these tools to drive powered assistive devices in free-living conditions.

Intensive cycle ergometer training improves gait speed and endurance in patients with Parkinson's disease: A comparison with treadmill training

PURPOSE

Cycle ergometer training improves gait in the elderly, but its effect in patients with Parkinson's disease (PD) is not completely known.

METHODS

Twenty-nine PD inpatients were randomized to treadmill (n = 13, PD-T) or cycle ergometer (n = 16, PD-C) training for 3 weeks, 1 hour/day. Outcome measures were distance travelled during the 6-min walking test (6MWT), spatio-temporal variables of gait assessed by baropodometry, the Timed Up and Go (TUG) duration, the balance score through the Mini-BESTest, and the score of the Unified Parkinson's Disease Rating Scale (UPDRS).

RESULTS

Sex, age, body mass index, disease duration, Hoehn-Yahr staging, comorbidity and medication did not differ between groups. At end of training, ANCOVA showed significant improvement, of similar degree, in both groups for 6MWT, speed, step length and cadence of gait, TUG, Mini-BESTest and UPDRS.

CONCLUSIONS

This pilot study shows that cycle ergometer training improves walking parameters and reduces clinical signs of PD, as much as treadmill training does. Gait velocity is accompanied by step lengthening, making the gait pattern close to that of healthy subjects. Cycle ergometer is a valid alternative to treadmill for improving gait in short term in patients with PD.

Feasibility of a Simplified, Clinically Oriented, Three-dimensional Gait Analysis System for the Gait Evaluation of Stroke Patients

Objective

Although previous studies have evidenced the value of three-dimensional gait analysis (3DGA) for evaluating gait disorder, the time-consuming measurement process and space requirement has hampered its use in the clinical setting. The aim of this study was to examine the feasibility of a simplified 3DGA system for stroke patients.

Methods

Thirteen pairs of stroke patients and age- (± 1 year), gender-, and gait speed- (± 0.5 m/s) matched controls were drawn from the Fujita Health University gait analysis database. 3DGA was performed using the KinemaTracer^® treadmill gait analysis system. Comparisons of the spatiotemporal and kinematic parameters were performed between stroke patients and matched controls. The correlations between items from the Wisconsin Gait Scale (WGS) and 3DGA data in stroke patients were also investigated.

Results

3DGA measurements clearly showed reduced toe clearance, hip flexion, and knee flexion in stroke patients compared with the matched controls. In contrast, significant increases were observed in hip elevation, shoulder elevation, shoulder lateral shift, and step width in stroke patients. For the four items drawn from the WGS, a significant correlation with three 3DGA parameters was observed: stance time on the impaired side, stance width, and knee flexion from toe off to midswing.

Conclusions

In this study, significant differences in gait parameters of stroke patients and age-, gender-, and speed-matched controls were found using a simplified 3DGA system. A significant correlation with WGS was also observed. These results support the validity of the clinical measurement of gait parameters using a simplified 3DGA system.

Combining Fast-Walking Training and a Step Activity Monitoring Program to Improve Daily Walking Activity After Stroke: A Preliminary Study

OBJECTIVES

To determine preliminary efficacy and to identify baseline characteristics predicting who would benefit most from fast walking training plus a step activity monitoring program (FAST+SAM) compared with fast walking training (FAST) alone in persons with chronic stroke.

DESIGN

Randomized controlled trial with blinded assessors.

SETTING

Outpatient clinical research laboratory.

PARTICIPANTS

Individuals (N=37) >6 months poststroke.

INTERVENTIONS

Subjects were assigned to either FAST, which was walking training at their fastest possible speed on the treadmill (30min) and overground 3 times per week for 12 weeks, or FAST+SAM. The step activity monitoring program consisted of daily step monitoring with an activity monitor, goal setting, and identification of barriers to activity and strategies to overcome barriers.

MAIN OUTCOME MEASURES

Daily step activity metrics (steps/day [SPD], time walking per day), walking speed, and 6-minute walk test (6MWT) distance.

RESULTS

There was a significant effect of time for both groups, with all outcomes improving from pre- to posttraining (all P values <.05). The FAST+SAM was superior to FAST for 6MWT (P=.018), with a larger increase in the FAST+SAM group. The interventions had differential effectiveness based on baseline step activity. Sequential moderated regression models demonstrated that for subjects with baseline levels of step activity and 6MWT distances that were below the mean, the FAST+SAM intervention was more effective than FAST (1715±1584 vs 254±933 SPD; P<.05 for overall model and ΔR(2) for SPD and 6MWT).

CONCLUSIONS

The addition of a step activity monitoring program to a fast walking training intervention may be most effective in persons with chronic stroke who have initial low levels of walking endurance and activity. Regardless of baseline performance, the FAST+SAM intervention was more effective for improving walking endurance.

Muscle Synergies in Cycling after Incomplete Spinal Cord Injury: Correlation with Clinical Measures of Motor Function and Spasticity

Background: After incomplete spinal cord injury (iSCI), patients suffer important sensorimotor impairments, such as abnormal locomotion patterns and spasticity. Complementary to current clinical diagnostic procedures, the analysis of muscle synergies has emerged as a promising tool to study muscle coordination, which plays a major role in the control of multi-limb functional movements.

Objective: Based on recent findings suggesting that walking and cycling share similar synergistic control, the analysis of muscle synergies during cycling might be explored as an early descriptor of gait-related impaired control. This idea was split into the following two hypotheses: (a) iSCI patients present a synergistic control of muscles during cycling; (b) muscle synergies outcomes extracted during cycling correlate with clinical measurements of gait performance and/or spasticity.

Methods: Electromyographic (EMG) activity of 13 unilateral lower limb muscles was recorded in a group of 10 healthy individuals and 10 iSCI subjects during cycling at four different cadences. A non-negative matrix factorization (NNMF) algorithm was applied to identify synergistic components (i.e., activation coefficients and muscle synergy vectors). Reconstruction goodness scores (VAF and r²) were used to evaluate the ability of a given number of synergies to reconstruct the EMG signals.

A set of metrics based on the similarity between pathologic and healthy synergies were correlated with clinical scales of gait performance and spasticity.

Results: iSCI patients preserved a synergistic control of muscles during cycling. The similarity with the healthy reference was consistent with the degree of the impairment, i.e., less impaired patients showed higher similarities with the healthy reference. There was a strong correlation between reconstruction goodness scores at 42 rpm and motor performance scales (TUG, 10-m test and WISCI II). On the other hand, the similarity between the healthy and affected synergies presented correlation with some spasticity symptoms measured by Penn, Modified Ashworth and SCATS scales.

Conclusion: Overall, the results of this study support the hypothesis that the analysis of muscle synergies during cycling can provide detailed quantitative assessment of functional motor impairments and symptoms of spasticity caused by abnormal spatiotemporal muscle co-activation following iSCI.

Plantarflexor weakness is a determinant of kinetic asymmetry during gait in post-stroke individuals walking with high levels of effort

BACKGROUND

Some studies in post-stroke individuals hypothesized that asymmetrical gait might be a strategy to symmetrize the effort in lower limb muscles. This study analyzed the asymmetry in the levels of effort, net joint moment during gait (walking moment) and maximal potential moment in the plantarflexors, hip flexors and extensors during gait.

METHODS

Twenty post-stroke and 10 healthy individuals were assessed when walking at a comfortable speed on a treadmill. Their efforts were estimated bilaterally with a biomechanical approach (muscular utilization ratio) which is the walking moment relative to the muscle's maximal capability (maximal potential moment). Pearson correlations were used to assess the relationship between asymmetry in walking moment and maximal potential moment.

FINDINGS

Healthy individuals presented symmetrical values of effort, walking moment and maximal potential moment for all muscle groups. Post-stroke individuals had asymmetrical walking moment in plantarflexion and hip extension. For the asymmetry in the levels of effort and maximal potential moment, they formed two subgroups; the low-effort subgroup presented symmetrical effort and their asymmetry in walking moment was not related to their asymmetry in maximal potential moment for plantarflexors (R = 0.44; P > 0.05). The high-effort subgroup presented asymmetrical effort (paretic side higher) and their asymmetry in walking moments was significantly associated to their asymmetry in maximal potential moment for plantarflexors and hip extensors (0.73≤R≤0.82; P<0.05).

INTERPRETATION

Asymmetry in muscular strength is a determinant of walking moment asymmetry when the level of effort is high. These results might guide the type of locomotor training.

Interrater and intrarater reliability and minimal detectable change of the Wisconsin Gait Scale when used to examine videotaped gait in individuals post-stroke

Background

Often, interventions targeting the kinematic and temporal and spatial changes in gait commonly seen after a stroke are based on observations of walking. Having the capacity to objectively identify such changes and track improvements over time using reliable and valid measures is important. The Wisconsin Gait Scale (WGS), which is comprised of 14 items, was developed specifically to examine and document gait changes occurring after a stroke. The purpose of the study was to explore the interrater and intrarater reliability and minimal detectable change (MDC) of the WGS when used by physical therapists to examine gait in adults post-stroke.

Methods

Fourteen physical therapists from 3 different acute inpatient rehabilitation centers rated videotapes of the gait of 6 adults post-stroke using the WGS. To minimize subject variability from fatigue, videotapes created by using 4 cameras provided right and left lateral, anterior, and posterior views of walking on a level surface. One complete ambulation trial from each subject post-stroke, which included 4 views of the same ambulation trial, was examined by the licensed physical therapists using the WGS. An opportunity was provided to review the tool and a practice trial was performed using an additional videotape not included in the analysis. Gait was examined on 2 different occasions separated by a period of approximately 21 days to minimize the effects of recall bias. Intraclass Correlation Coefficients (ICC) were used to examine the interrater and intrarater reliability of the WGS.

Results

Interrater (ICC = 0.83) and intrarater (ICC = 0.91) reliability were both good. The standard error of the measurement (SEM) was 1.47 and the MDC₉₅ was 4.24. There was no statistically significant difference between the scores on the WGS when comparing the 2 different sessions.

Conclusions

The WGS shows promise as an instrument that can make observational gait analysis more reliable. High intrarater reliability and low SEM suggests that the WGS is stable when administered across multiple sessions by the same rater. The ICC for interrater reliability was also good, which suggests that multiple examiners can effectively use the instrument. With minimal training, the physical therapists in the study were able to produce highly reliable results using the WGS to objectively document gait dysfunction.

Stroke rehabilitation: clinical picture, assessment, and therapeutic challenge

This chapter reviews the evolution of stroke rehabilitation in the last 20 years. It begins by describing the different types of stroke that can occur in adults, their potential consequences on a person's capacity to function in daily life and statistics on the number of strokes and their burden on families and the economy. The assessment of stroke severity, recovery of function over time, and the impact of initial stroke severity and age on potential recovery are then addressed as well as the concept of rehabilitation to enhance recovery. Fueled by the synthesis of an ever-increasing research knowledge base and the creation of stroke rehabilitation recommendations for optimal delivery of rehabilitation services and of therapeutic interventions, stroke rehabilitation has changed dramatically. Examples of improvements in stroke rehabilitation in Canada are given with emphasis on the "best practices" inspired stroke rehabilitation continuum recently recommended for the Province of Quebec. The need for an improved community-based rehabilitation approach that includes regular follow-ups and community-based programs promoting reintegration is emphasized. The importance of knowledge translation strategies to promote the uptake of best-practice recommendations is illustrated by describing the activities of the Sensorimotor Rehabilitation Research Team. Over the past 3 years, the researchers of this team and clinicians in three rehabilitation centers, two in Montreal and one in Quebec City, have collaborated to adopt standardized assessment tools, create a common stroke registry, a best-practice recommended approach to interventions and the participation of clinicians in the research process.

Effects of walking with loads above the ankle on gait parameters of persons with hemiparesis after stroke

BACKGROUND

Walking with a load at the ankle during gait training is a simple way to resist lower limb movements to induce functional muscle strengthening. This study investigated the effects of walking with different loads attached above the paretic ankle on biomechanical gait parameters during over ground walking in post-stroke participants.

METHODS

Ten participants with moderate chronic hemiparesis were evaluated while walking over ground with three different loads (0.5, 1.0, and 1.5kg) attached above the paretic ankle. Gait speed, cadence, step lengths as well as hip and knee angular displacements, joint moments and power of the paretic limb were compared while walking with and without loads.

FINDINGS

Walking with a load led to an increased in gait speed (+0.03-0.05m/s), and in step length of the paretic leg (+5.6 to 9.4% step length, effect size=0.49-0.63), but not of the non-paretic leg. The proportion of the stance and swing phases did not change. Maximal joint moments (+20 to 48%, effect size=0.26-0.55) and power (+20 to 114%, effect size=0.30-0.57) increases varied across participants but were mostly affected in early stance at the hip and during the late swing phase at the knee. Mean angular displacement changes were less than 4°.

INTERPRETATION

Post-stroke participants are able to increase hip and knee power bursts to meet the increased mechanical demand of added loads attached to the paretic ankle, while preserving the basic pattern of walking. Further study is needed before using loading to functionally strengthen paretic muscles.

Analysis of biomechanical data to determine the degree of users participation during robotic-assisted gait rehabilitation

Recent studies have shown evidence indicating that effective robotic rehabilitation is only possible when the user actively participates during training. Providing a complete effective biofeedback to the patient representing his compliance to the therapy and his performance is thought that his active participation will be enhanced significantly, thus, improving his rehabilitation. We have performed a study with the driven gait orthosis (DGO) Lokomat (Hocoma AG, Volketswil, Switzerland). The objective of the present study is the analysis of the effect of different types of participation (attention to the functional task) from subjects receiving robotic assisted gait training on the kinematic and kinetic patterns. The obtained results provide useful evidence of specific biomechanical features that can be used to design more useful, robust, focused and intuitive biomechanical biofeedback during robotic assisted gait rehabilitation in stroke survivors.

Effects of robotic guidance on the coordination of locomotion

BACKGROUND

Functional integration of motor activity patterns enables the production of coordinated movements, such as walking. The activation of muscles by weightened summation of activation signals has been demonstrated to represent the spatiotemporal components that determine motor behavior during walking. Exoskeleton robotic devices are now often used in the rehabilitation practice to assist physical therapy of individuals with neurological disorders. These devices are used to promote motor recovery by providing guidance force to the patients. The guidance should in principle lead to a muscle coordination similar to physiological human walking. However, the influence of robotic devices on locomotor patterns needs still to be characterized. The aim of this study was to analyze the effect of force guidance and gait speed on the modular organization of walking in a group of eight healthy subjects.

METHOD

A group of healthy subjects walked on a treadmill with and without robotic aiding at speeds of 1.5, 2.0 and 2.5 Km/h. The guidance force was varied between 20%, 40%, 70% and 100% level of assistance. EMG recordings were obtained from seven leg muscles of the dominant leg and kinematic and kinetic features of the knee and hip joints were extracted.

RESULTS

Four motor modules were sufficient to represent the variety of behavioral goals demanded during robotic guidance, with similar relationships between muscle patterns and biomechanical parameters across subjects, confirming that the low-dimensional and impulsive control of human walking is maintained using robotic force guidance. The conditions of guidance force and speed that maintained correct and incorrect (not natural) modular control were identified.

CONCLUSION

In neurologically intact subjects robotic-guided walking at various force guidance and speed levels does not alter the basic locomotor control and timing. This allows the design of robotic-aided rehabilitation strategies aimed at the modulation of motor modules, which are altered in stroke.

Assessing post-stroke behavior in mouse models of focal ischemia

Experimental treatment strategies and neuroprotective drugs that showed therapeutic promise in animal models of stroke have failed to produce beneficial effects in human stroke patients. The difficulty in translating preclinical findings to humans represents a major challenge in cerebrovascular research. The reasons behind this translational road block might be explained by a number of factors, including poor quality control in various stages of the research process, the validity of experimental stroke models, and differences in drug administration and pharmacokinetics. Another major difference between animal studies and clinical trials is the choice of end point or outcome measures. Here, we discuss the necessity of poststroke behavioral testing to bridge the gap between clinical and experimental end points. We review established sensory-motor tests for outcome determination after focal ischemia based on the published literature as well as our own personal experience. Selected tests are described in more detail and good laboratory practice standards for behavioral testing are discussed. This review is intended for stroke researchers planning to use behavioral testing in mice.

Use of segmental coordination analysis of nonparetic and paretic limbs during obstacle clearance in community-dwelling persons after stroke

OBJECTIVE

To use a segment coordination analysis to identify coordination differences between the paretic and nonparetic limbs for obstacle clearance in community-dwelling persons after stroke.

DESIGN

Within-participant design.

SETTING

Gait analysis laboratory.

PARTICIPANTS

Six community-dwelling persons with a stroke (excluding cerebellar stroke).

METHODS

Participants stepped over obstacles of 2 different heights (7.5% and 15% of leg length), leading alternately with their paretic and nonparetic limbs.

MAIN OUTCOME MEASUREMENTS

Kinematic data were collected, and segment elevation angles (absolute segment angular position with respect to vertical) were calculated for the thigh, shank, and foot segments. Established mathematical techniques related to the planar law of intersegmental coordination (principal component analysis to quantify covariance and temporal phase relationships among elevation angles) were then applied to compare and contrast the coordination of these segment elevation angle trajectories between paretic and nonparetic limbs.

RESULTS

Segment covariance in elevation angles followed the planar law of intersegmental coordination during level walking (ie, 3 elevation angles that form a plane and the variance explained by 2 principal components) for both paretic and nonparetic limbs. During obstacle clearance, however, relationships between covariance plane characteristics and phase differences for elevation angles of adjacent segments differed in the nonparetic limb, likely related to a need for greater limb elevation for obstacle clearance during paretic limb support or an altered foot trajectory, which resulted from preobstacle foot placement.

CONCLUSIONS

The present coordination analysis suggests the preservation of basic control mechanisms in the paretic limb during obstacle clearance after stroke and also reveals its specific motor control compensations. However, a larger study with differing levels of stroke severity must be conducted to understand how the evaluation of intersegmental coordination during walking could guide treatment of specific locomotor control deficits in stroke rehabilitation.

Ambulation and spinal cord injury

Walking is possible for many patients with a spinal cord injury. Avenues enabling walking include braces, robotics and FES. Among the benefits are improved musculoskeletal and mental health, however unrealistic expectations may lead to negative changes in quality of life. Use rigorous assessment standards to gauge the improvement of walking during the rehabilitation process, but also yearly. Continued walking after discharge may be limited by challenges, such as lack of accessibility in and outside the home, and complications, such as shoulder pain or injuries from falls. It is critical to determine the risks and benefits of walking for each patient.