Effects of aerobic treadmill training on gait velocity, cadence, and gait symmetry in chronic hemiparetic stroke: a preliminary report

Effect of Purposely Induced Asymmetric Walking Perturbations on Limb Loading After Anterior Cruciate Ligament Reconstruction

Background

Patients often sustain prolonged neuromuscular dysfunction after anterior cruciate ligament reconstruction (ACLR). This dysfunction can present as interlimb loading rate asymmetries linked to reinjury and knee osteoarthritis progression.

Purpose/Hypothesis

To evaluate how asymmetric walking protocols can reduce interlimb loading rate asymmetry in patients after ACLR. It was hypothesized that asymmetric walking perturbations would (1) produce a short-term adaptation of interlimb gait symmetry and (2) induce the temporary storage of these new gait patterns after the perturbations were removed.

Study Design

Descriptive laboratory study.

Methods

Fifteen patients who had undergone ACLR were asked to perform an asymmetric walking protocol during the study period (2022-2023). First, to classify each limb as overloaded or underloaded based on the vertical ground-reaction force loading rate for each limb, participants were asked to perform baseline symmetric walking trials. Participants then performed an asymmetric walking trial for 10 minutes, where one limb was moving 0.5 m/s faster than the other limb (1 vs 1.5 m/s), followed by a 2-minute 1 m/s symmetric deadaptation walking trial. This process was repeated with the limb speeds switched for a second asymmetric trial.

Results

Participants adopted a new, symmetric interlimb loading rate gait pattern over time in response to the asymmetric trial, where the overloaded limb was set at 1 m/s. A linear mixed-effects model detected a significant change in gait dynamics (P < .001). The participants exhibited negative aftereffects after this asymmetric perturbation, indicating the temporary storage of the new gait pattern. No positive short-term gait adaptation or storage was observed when the overloaded limb was set to a faster speed.

Conclusion

Asymmetric walking successfully produced the short-term adaptation of interlimb loading rate symmetry in patients after ACLR and induced the temporary storage of these gait patterns in the initial period when the perturbation was removed.

Clinical Relevance

These findings are promising, as they suggest that asymmetric walking could serve as an effective gait retraining protocol that has the potential to improve long-term outcomes in patients after ACLR.

Comparison of Walking Quality Variables between End-Stage Osteonecrosis of Femoral Head Patients and Healthy Subjects by a Footscan Plantar Pressure System

Background and Objectives: Osteonecrosis of the femoral head (ONFH) is a progressive disease with a complex etiology and unknown pathogenesis. Gait analysis can objectively assess the functional behavior of the foot, thus revealing essential aspects and influencing factors of gait abnormalities. The aim of this study was to evaluate the differences in spatiotemporal parameters, static and dynamic plantar pressure parameters, and symmetry indices between patients with ONFH and healthy subjects. Materials and Methods: The study population consisted of 31 ONFH patients and 31 healthy volunteers. Gait parameters were obtained from the plantar pressure analysis system for both the ONFH and healthy groups. The symmetry index was calculated according to a formula, including spatiotemporal parameters, static and dynamic plantar pressure distribution, percentage of regional impulse, and percentage of the restricted contact area. Results: Compared with healthy controls, patients with ONFH had slower walking speed, shorter step length and stride length, and increased stride time, stance time, and percentage of stance. patients with ONFH had lower plantar static pressure on the affected side and higher contralateral plantar static pressure during stance than controls. During walking, the peak pressures in all regions on the affected side and the peak pressure in the toe 1 and metatarsal 3 regions on the healthy side were lower in ONFH patients than in controls. The percentage of contact area and regional impulse in the heel of both limbs were higher in ONFH patients than in the control group. The symmetry indexes of stride time, stance time, step length, maximum force, impulse and contacted area were significantly increased in ONFH patients compared to controls, with decreased symmetry. Conclusions: Osteonecrosis of the femoral head leads to characteristic changes in plantar pressure distribution. These changes may be interpreted as an attempt by patients with ONFH to reduce the load on the affected limb. Plantar pressure analysis may assist in the diagnosis of ONFH and can provide an objective quantitative indicator for the assessment of subsequent treatment outcomes.

Effects of Transcranial Direct Current Stimulation Combined with Treadmill Training on Kinematics and Spatiotemporal Gait Variables in Stroke Survivors: A Randomized, Triple-Blind, Sham-Controlled Study

The present study assessed the effects of anodal transcranial direct current stimulation (tDCS) combined with treadmill training on spatiotemporal and kinematic variables in stroke survivors using gait speed as the primary outcome. A randomized, sham-controlled, triple-blind, study was conducted involving 28 patients with hemiparesis allocated to two groups. The experimental group was submitted to treadmill training combined with anodal tDCS over the primary motor cortex (M1) of the damaged hemisphere. The control group was submitted to treadmill training combined with sham tDCS. Stimulation was administered (2 mA, 20 min) five times a week for two weeks during treadmill training. No significant differences (p > 0.05) in spatiotemporal variables were found in the intra-group and inter-group analyses. However, the experimental group demonstrated improvements in kinematic variables of the knee and ankle (p < 0.05) and these results were maintained one month after the end of the intervention. The inter-group analysis revealed significant differences (p < 0.05) with regard to the pelvis, hip and knee. Anodal tDCS over M1 of the damaged hemisphere combined with treadmill training did not affect spatiotemporal variables, but promoted improvements in kinematic variables of the pelvis, hip, knee and ankle and results were maintained one month after treatment.

"Magic" Number of Treadmill Sessions Needed to Achieve Meaningful Change in Gait Speed After Stroke: A Systematic Review

ABSTRACT

The purpose of this systematic review was to determine the number of treadmill training sessions needed to make a meaningful change in gait speed for chronic stroke survivors. Relevant databases were searched up through February 2020. Articles were included if they fit the following criteria: stroke onset more than 5 mos, intention to treat with traditional treadmill training, and gait speed included as an outcome. Change in gait speed after intervention was used to classify treadmill groups as responders (at least 0.1 m/sec change) or nonresponders (less than 0.1 m/sec change). Seventeen articles met our criteria, resulting in a total of 19 intervention groups. Ten groups were classified as responders and completed a mean of 30.5 sessions within 6 wks, whereas nonresponders completed 20.4 sessions within 10 wks, indicating that at least 30 treadmill sessions (preferably in a period of 10 wks and at least 40 mins per session) is necessary to reach a meaningful change in gait speed. Although these trends were noted between the responder and nonresponder groups, no firm conclusions can be drawn regarding the "magic" number of sessions chronic stroke survivors should perform given the low correlation between number of sessions and change in gait speed.

Assessment Methods of Post-stroke Gait: A Scoping Review of Technology-Driven Approaches to Gait Characterization and Analysis

Background: Gait dysfunction or impairment is considered one of the most common and devastating physiological consequences of stroke, and achieving optimal gait is a key goal for stroke victims with gait disability along with their clinical teams. Many researchers have explored post stroke gait, including assessment tools and techniques, key gait parameters and significance on functional recovery, as well as data mining, modeling and analyses methods.

Research Question: This study aimed to review and summarize research efforts applicable to quantification and analyses of post-stroke gait with focus on recent technology-driven gait characterization and analysis approaches, including the integration of smart low cost wearables and Artificial Intelligence (AI), as well as feasibility and potential value in clinical settings.

Methods: A comprehensive literature search was conducted within Google Scholar, PubMed, and ScienceDirect using a set of keywords, including lower extremity, walking, post-stroke, and kinematics. Original articles that met the selection criteria were included.

Results and Significance: This scoping review aimed to shed light on tools and technologies employed in post stroke gait assessment toward bridging the existing gap between the research and clinical communities. Conventional qualitative gait analysis, typically used in clinics is mainly based on observational gait and is hence subjective and largely impacted by the observer's experience. Quantitative gait analysis, however, provides measured parameters, with good accuracy and repeatability for the diagnosis and comparative assessment throughout rehabilitation. Rapidly emerging smart wearable technology and AI, including Machine Learning, Support Vector Machine, and Neural Network approaches, are increasingly commanding greater attention in gait research. Although their use in clinical settings are not yet well leveraged, these tools promise a paradigm shift in stroke gait quantification, as they provide means for acquiring, storing and analyzing multifactorial complex gait data, while capturing its non-linear dynamic variability and offering the invaluable benefits of predictive analytics.

Using Biofeedback to Reduce Step Length Asymmetry Impairs Dynamic Balance in People Poststroke

BACKGROUND

People poststroke often walk with a spatiotemporally asymmetric gait, due in part to sensorimotor impairments in the paretic lower extremity. Although reducing asymmetry is a common objective of rehabilitation, the effects of improving symmetry on balance are yet to be determined.

OBJECTIVE

We established the concurrent validity of whole-body angular momentum as a measure of balance, and we determined if reducing step length asymmetry would improve balance by decreasing whole-body angular momentum.

METHODS

We performed clinical balance assessments and measured whole-body angular momentum during walking using a full-body marker set in a sample of 36 people with chronic stroke. We then used a biofeedback-based approach to modify step length asymmetry in a subset of 15 of these individuals who had marked asymmetry and we measured the resulting changes in whole-body angular momentum.

RESULTS

When participants walked without biofeedback, whole-body angular momentum in the sagittal and frontal plane was negatively correlated with scores on the Berg Balance Scale and Functional Gait Assessment supporting the validity of whole-body angular momentum as an objective measure of dynamic balance. We also observed that when participants walked more symmetrically, their whole-body angular momentum in the sagittal plane increased rather than decreased.

CONCLUSIONS

Voluntary reductions of step length asymmetry in people poststroke resulted in reduced measures of dynamic balance. This is consistent with the idea that after stroke, individuals might have an implicit preference not to deviate from their natural asymmetry while walking because it could compromise their balance. Clinical Trials Number: NCT03916562.

Single-session training on an ascending treadmill slope: effects on gait parameters in persons with stroke. A pilot study

OBJECTIVE

Treadmill training with an upward incline could improve gait parameters altered in persons with stroke, especially lower limb flexion. This study aimed to determine the effects of a treadmill single-session training with a 10% upward incline on biomechanical gait parameters in persons with stroke.

METHODS

Fifteen persons with stroke-related hemiparesis performed a 20-min treadmill training session with a 10% ascending incline in this interventional pilot study. Spatiotemporal, kinematic and kinetic parameters were evaluated, overground, with a tridimensional optoelectronic system, before the session, immediately after and after a 20-min rest period.

RESULTS

The single-session training on a treadmill with a 10% incline has significantly increased hip flexion peak on the paretic side (39.8°± 8.1 in baseline to 42.7°± 8.6 after the session, P < 0.001, large effect size) and knee flexion peak on the paretic side (39.9°± 11.6 in baseline to 43.1°± 11.7 after the session, P = 0.004, large effect size). Gait speed, other spatiotemporal gait parameters and propulsion on the paretic side were also significantly increased (P < 0.05, all large effects size). These short-term changes were maintained after the break.

CONCLUSIONS

A treadmill single-session training with a 10% upward incline induces biomechanical changes in people with stroke. The environmental constraints of this training could explain these biomechanical adaptations, concerning especially paretic hip and knee flexion.

Immersive virtual reality during gait rehabilitation increases walking speed and motivation: a usability evaluation with healthy participants and patients with multiple sclerosis and stroke

Background

The rehabilitation of gait disorders in patients with multiple sclerosis (MS) and stroke is often based on conventional treadmill training. Virtual reality (VR)-based treadmill training can increase motivation and improve therapy outcomes. The present study evaluated an immersive virtual reality application (using a head-mounted display, HMD) for gait rehabilitation with patients to (1) demonstrate its feasibility and acceptance and to (2) compare its short-term effects to a semi-immersive presentation (using a monitor) and a conventional treadmill training without VR to assess the usability of both systems and estimate the effects on walking speed and motivation.

Methods

In a within-subjects study design, 36 healthy participants and 14 persons with MS or stroke participated in each of the three experimental conditions (VR via HMD, VR via monitor, treadmill training without VR).

Results

For both groups, the walking speed in the HMD condition was higher than in treadmill training without VR and in the monitor condition. Healthy participants reported a higher motivation after the HMD condition as compared with the other conditions. Importantly, no side effects in the sense of simulator sickness occurred and usability ratings were high. No increases in heart rate were observed following the VR conditions. Presence ratings were higher for the HMD condition compared with the monitor condition for both user groups. Most of the healthy study participants (89%) and patients (71%) preferred the HMD-based training among the three conditions and most patients could imagine using it more frequently.

Conclusions

For the first time, the present study evaluated the usability of an immersive VR system for gait rehabilitation in a direct comparison with a semi-immersive system and a conventional training without VR with healthy participants and patients. The study demonstrated the feasibility of combining a treadmill training with immersive VR. Due to its high usability and low side effects, it might be particularly suited for patients to improve training motivation and training outcome e. g. the walking speed compared with treadmill training using no or only semi-immersive VR. Immersive VR systems still require specific technical setup procedures. This should be taken into account for specific clinical use-cases during a cost–benefit assessment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12984-021-00848-w.

Changes in Walking Speed After High-Intensity Treadmill Training Are Independent of Changes in Spatiotemporal Symmetry After Stroke

Objectives: Decreased walking speeds and spatiotemporal asymmetry both occur after stroke, but it is unclear whether and how they are related. It is also unclear whether rehabilitation-induced improvements in walking speed are associated with improvements in symmetry or greater asymmetry. High-intensity speed-based treadmill training (HISTT) is a recent rehabilitative strategy whose effects on symmetry are unclear. The purpose of this study was to: (1) assess whether walking speed is cross-sectionally associated with spatiotemporal symmetry in chronic stroke, (2) determine whether HISTT leads to changes in the spatiotemporal symmetry of walking, and (3) evaluate whether HISTT-induced changes in walking speed are associated with changes in spatiotemporal symmetry.

Methods: Eighty-one participants with chronic stroke performed 4 weeks of HISTT. At pre, post, and 3-month follow-up assessments, comfortable and maximal walking speed were measured with the 10-meter walk test, and spatiotemporal characteristics of walking were measured with the GAITRite mat. Step length and swing time were expressed as symmetry ratios (paretic/non-paretic). Changes in walking speed and symmetry were calculated and the association was determined.

Results: At pre-assessment, step length and swing time asymmetries were present (p < 0.001). Greater temporal symmetry was associated with faster walking speeds (p ≤ 0.001). After HISTT, walking speeds increased from pre-assessment to post-assessment and follow-up (p ≤ 0.002). There were no changes in spatiotemporal symmetry (p ≥ 0.10). Change in walking speed was not associated with change in spatial or temporal symmetry from pre- to post-assessment or from post-assessment to follow-up (R² ≤ 0.01, p ≥ 0.37).

Conclusions: HISTT improves walking speed but does not systematically improve or worsen spatiotemporal symmetry. Clinicians may need to pair walking interventions like HISTT with another intervention designed to improve walking symmetry simultaneously. The cross-sectional relation between temporal symmetry and walking speed may be mediated by other factors, and not be causative.

Cerebellar Transcranial Direct Current Stimulation for Motor Learning in People with Chronic Stroke: A Pilot Randomized Controlled Trial

Cerebellar transcranial direct current stimulation (ctDCS) is a non-invasive brain stimulation technique that alters neural plasticity through weak, continuous, direct currents delivered to the cerebellum. This study aimed to evaluate the feasibility of conducting a randomized controlled trial (RCT) delivering three consecutive days of ctDCS during split-belt treadmill training (SBTT) in people with chronic stroke. Using a double-blinded, parallel-group RCT design, eligible participants were randomly allocated to receive either active anodal ctDCS or sham ctDCS combined with SBTT on three consecutive days. Outcomes were assessed at one-week follow-up, using step length symmetry as a measure of motor learning and comfortable over-ground walking speed as a measure of walking capacity. The feasibility of the RCT protocol was evaluated based on recruitment, retention, protocol deviations and data completeness. The feasibility of the intervention was assessed based on safety, adherence and intervention fidelity. Of the 26 potential participants identified over four months, only four were enrolled in the study (active anodal ctDCS n = 1, sham ctDCS n = 3). Both the inclusion criteria and the fidelity of the SBTT relied upon the accurate estimation of step length asymmetry. The method used to determine the side of the step length asymmetry was unreliable and led to deviations in the protocol. The ctDCS intervention was well adhered to, safe, and delivered as per the planned protocol. Motor learning outcomes for individual participants revealed that treadmill step length symmetry remained unchanged for three participants but improved for one participant (sham ctDCS). Comfortable over-ground walking speed improved for two participants (sham ctDCS). The feasibility of the planned protocol and intervention was limited by intra-individual variability in the magnitude and side of the step length asymmetry. This limited the sample and compromised the fidelity of the SBTT intervention. To feasibly conduct a full RCT investigating the effect of ctDCS on locomotor adaptation, a reliable method of identifying and defining step length asymmetry in people with stroke is required. Future ctDCS research should either optimize the methods for SBTT delivery or utilize an alternative motor adaptation task.

Augmenting propulsion demands during split-belt walking increases locomotor adaptation of asymmetric step lengths

Background

Promising studies have shown that the gait symmetry of individuals with hemiparesis due to brain lesions, such as stroke, can improve through motor adaptation protocols forcing patients to use their affected limb more. However, little is known about how to facilitate this process. Here we asked if increasing propulsion demands during split-belt walking (i.e., legs moving at different speeds) leads to more motor adaptation and more symmetric gait in survivors of a stroke, as we previously observed in subjects without neurological disorders.

Methods

We investigated the effect of propulsion forces on locomotor adaptation during and after split-belt walking in the asymmetric motor system post-stroke. To test this, 12 subjects in the chronic phase post-stroke experienced a split-belt protocol in a flat and incline session so as to contrast the effects of two different propulsion demands. Step length asymmetry and propulsion forces were used to compare the motor behavior between the two sessions because these are clinically relevant measures that are altered by split-belt walking.

Results

The incline session resulted in more symmetric step lengths during late split-belt walking and larger after-effects following split-belt walking. In both testing sessions, subjects who have had a stroke adapted to regain speed and slope-specific leg orientations similarly to young, intact adults. Importantly, leg orientations, which were set by kinetic demands, during baseline walking were predictive of those achieved during split-belt walking, which in turn predicted each individual’s post-adaptation behavior. These results are relevant because they provide evidence that survivors of a stroke can generate the leg-specific forces to walk more symmetrically, but also because we provide insight into factors underlying the therapeutic effect of split-belt walking.

Conclusions

Individuals post-stroke at a chronic stage can adapt more during split-belt walking and have greater after-effects when propulsion demands are augmented by inclining the treadmill surface. Our results are promising since they suggest that increasing propulsion demands during paradigms that force patients to use their paretic side more could correct gait asymmetries post-stroke more effectively.

Improving spatiotemporal gait parameters in spastic diplegic children using treadmill gait training

BACKGROUND

Even though several physiotherapy techniques help to improve the spatiotemporal gait parameters of diplegic children, the efficacy of treadmill gait training together with conventional treatment techniques on spatiotemporal parameter improvement needs more investigation.

OBJECTIVE

This study's main purpose is to investigate the effect of treadmill gait training as an adjunct to conventional physiotherapy treatment on the spatiotemporal gait parameters of diplegic children.

METHODS

Twenty diplegic children were distributed randomly into two equal groups (a control group of ten children who received a traditional treatment and an experimental group of ten children who received the traditional treatment together with treadmill gait training). Gait data were collected using a Vicon three-dimensional motion analysis system during regular walking.

RESULTS

Walking speed, cadence, step length, stride length, and single limb support were enhanced in both groups (p < 0.05). Cadence and walking speed increased by 6.5 steps/min and 0.2 m/sec respectively in the experimental group, compared to the control group. Also, step length, stride length and single limb support time increased by 0.13 m, 0.27 m, and 0.07 s respectively in the experimental group, compared to the control group.

CONCLUSION

The use of treadmill gait training together with conventional physical therapy treatment enhances the walking performance of diplegic children by improving several spatiotemporal gait parameters. Furthermore, walking balance is improved by increasing the single-leg support time.

Novel gait training alters functional brain connectivity during walking in chronic stroke patients: a randomized controlled pilot trial

Background

A recent study has demonstrated that a turning-based treadmill program yields greater improvements in gait speed and temporal symmetry than regular treadmill training in chronic stroke patients. However, it remains unknown how this novel and challenging gait training shapes the cortico-cortical network and cortico-spinal network during walking in chronic stroke patients. The purpose of this study was to examine how a novel type of gait training, which is an unfamiliar but effective task for people with chronic stroke, enhances brain reorganization.

Methods

Subjects in the experimental and control groups received 30 min of turning-based treadmill training and regular treadmill training, respectively. Cortico-cortical connectivity and cortico-muscular connectivity during walking and gait performance were assessed before and after completing the 12-session training.

Results

Eighteen subjects (n = 9 per group) with a mean age of 52.5 ± 9.7 years and an overground walking speed of 0.61 ± 0.26 m/s consented and participated in this study. There were significant group by time interactions for gait speed, temporal gait symmetry, and cortico-cortical connectivity as well as cortico-muscular connectivity in walk-related frequency (24–40 Hz) over the frontal-central-parietal areas. Compared with the regular treadmill training, the turning-based treadmill training resulted in greater improvements in these measures. Moreover, the increases in cortico-cortical connectivity and cortico-muscular connectivity while walking were associated with improvements in temporal gait symmetry.

Conclusions

Our findings suggest this novel turning-based treadmill training is effective for enhancing brain functional reorganization underlying cortico-cortical and corticomuscular mechanisms and thus may result in gait improvement in people with chronic stroke.

Trial registration

ACTRN12617000190303. Registered 3 February 2017, retrospectively registered.

High-frequency repetitive transcranial magnetic stimulation enhanced treadmill training effects on gait performance in individuals with chronic stroke: A double-blinded randomized controlled pilot trial

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) combined with treadmill training has been suggested to modulate corticomotor activity and improve gait performance in people with Parkinson's disease.

RESEARCH QUESTION

It is unclear whether this combination therapy has a similar effect in people with stroke. The current study aimed to investigate whether high-frequency rTMS enhances the effects of subsequent treadmill training in individuals with chronic stroke.

METHODS

Fourteen participants meeting the selection criteria were randomly assigned to either the experimental (n = 8) or control (n = 6) group. The experimental group received 5 Hz rTMS prior to treadmill training three times per week for 3 weeks. The control group received sham rTMS before treadmill training. Walking speed, gait symmetry, corticomotor excitability, motor function of the lower extremities, and muscle activity during walking were measured before intervention, after intervention, and at 1-month follow-up.

RESULTS

The walking speed, spatial asymmetry of gait, and motor function of the lower extremities improved significantly in the experimental group, and these improvements exhibited significant differences in between-group comparisons. However, there was no significant difference in corticomotor excitability or brain asymmetry ratio after the intervention in each group.

SIGNIFICANCE

The current results revealed that applying 5 Hz high-frequency rTMS over the leg motor cortex in the affected hemisphere enhanced the effects of subsequent treadmill training on gait speed and spatial asymmetry in individuals with chronic stroke. Improvement in gait speed persisted for at least 1 month in individuals with chronic stroke.

Influence of visual feedback and rhythmic auditory cue on walking of chronic stroke patient induced by treadmill walking in real-time basis

BACKGROUND

Many patients who have suffered from a stroke show decreased walking ability, characterized by asymmetric gait. For such patients, the recovery of symmetry in walking is important.

OBJECTIVES

The purpose of this study is to investigate the effect of visual feedback with rhythmic auditory cue on treadmill gait in persons with chronic stroke.

METHODS

Seventeen chronic subjects who have been diagnosed at least six months or before were recruited in G Hospital, located in Incheon. The subjects who were enrolled in this study were instructed to walk randomly on a treadmill: treadmill with visual feedback and rhythmic auditory cue (VF+RAC), treadmill with visual feedback (VF), general treadmill (Control; non-feedback). Three factors were observed and estimated: paretic step length, non-paretic step length, spatial asymmetry ratio at comfortable speed. Also, in VF and VF+RAC, calibration of feedback accuracy was measured.

RESULTS

Results showed that paretic step length and spatial asymmetry ratio were significantly improved in VF+RAC compared to that of the VF and control (p < 0.05). Accuracies of paretic and non-paretic leg were significantly increased in VF+RAC than that of the VF (p < 0.05).

CONCLUSIONS

According to this result, it seems that application of VF+RAC in treadmill gait significantly improved gait of these patients. Also, we can conclude that VF+RAC in treadmill gait is thought to be useful in clinical settings where there are many chronic patients who are in need of improvement in their gait ability.

The role of movement errors in modifying spatiotemporal gait asymmetry post stroke: a randomized controlled trial

OBJECTIVE

Current rehabilitation to improve gait symmetry following stroke is based on one of two competing motor learning strategies: minimizing or augmenting symmetry errors. We sought to determine which of those motor learning strategies best improves overground spatiotemporal gait symmetry.

DESIGN

Randomized controlled trial.

SETTING

Rehabilitation research lab.

SUBJECTS

In all, 47 participants (59 ± 12 years old) with chronic hemiparesis post stroke and spatiotemporal gait asymmetry were randomized to error augmentation, error minimization, or conventional treadmill training (control) groups.

INTERVENTIONS

To augment or minimize asymmetry on a step-by-step basis, we developed a responsive, "closed-loop" control system, using a split-belt instrumented treadmill that continuously adjusted the difference in belt speeds to be proportional to the patient's current asymmetry.

MAIN MEASURES

Overground spatiotemporal asymmetries and gait speeds were collected prior to and following 18 training sessions.

RESULTS

Step length asymmetry reduced after training, but stance time did not. There was no group × time interaction. Gait speed improved after training, but was not affected by type of asymmetry, or group. Of those who trained to modify step length asymmetry, there was a moderately strong linear relationship between the change in step length asymmetry and the change in gait speed.

CONCLUSION

Augmenting errors was not superior to minimizing errors or providing only verbal feedback during conventional treadmill walking. Therefore, the use of verbal feedback to target spatiotemporal asymmetry, which was common to all participants, appears to be sufficient to reduce step length asymmetry. Alterations in stance time asymmetry were not elicited in any group.

Changes in Gait Symmetry After Training on a Treadmill with Biofeedback in Chronic Stroke Patients: A 6-Month Follow-Up From a Randomized Controlled Trial

Background

One of the most significant challenges for patients who survive a stroke is relearning basic motor tasks such as walking. The goal of this study was to evaluate whether training on a treadmill with visual biofeedback improves gait symmetry, as well as spatiotemporal and kinematic gait parameters, in stroke patients.

Material/Methods

Thirty patients in the chronic phase after a stroke were randomly allocated into groups with a rehabilitation program of treadmill training with or without visual biofeedback. The training program lasted 10 days. Spatiotemporal and kinematic gait parameters were evaluated. For all parameters analyzed, a symmetrical index was calculated. Follow-up studies were performed 6 months after completion of the program.

Results

The symmetrical index had significantly normalized in terms of the step length (p=0.006), stance phase time, and inter-limb ratio in the intervention group. After 6 months, the improvement in the symmetry of the step length had been maintained. In the control group, no statistically significant change was observed in any of the parameters tested. There was no significant difference between the intervention group and the control group on completion of the program or at 6 months following the completion of the program.

Conclusions

Training on a treadmill has a significant effect on the improvement of spatiotemporal parameters and symmetry of gait in patients with chronic stroke. In the group with the treadmill training using visual biofeedback, no significantly greater improvement was observed.

Randomized comparison trial of gait training with and without compelled weight-shift therapy in individuals with chronic stroke

Objective:

To compare the effects of gait training combined with compelled weight-shift therapy and gait training alone on velocity and gait symmetry in patients with chronic stroke.

Design:

Single-blind randomized controlled trial.

Participants:

Patients ( N=28) with chronic stroke and stance asymmetry toward the non-paretic side.

Interventions:

Six weeks of gait training combined with compelled weight-shift therapy via a shoe lift applied under the non-paretic leg (experimental group, n=14) or gait training alone (control group, n=14).

Main measures:

Percentage of total body weight carried by the paretic limb, gait velocity and gait spatiotemporal symmetry ratios including step symmetry, stance symmetry, swing symmetry and overall temporal symmetry.

Results:

When comparing the two groups, weight bearing on the affected side increased more significantly in experimental group than in control group (40.14±3.77, 38.28±4.06) after the end of treatment and also after a three-month follow-up (44.42±3.5, 38.5±3.77) (P<0.05). Among the experimental and control groups, there were no significant differences of gait velocity (cm/s) after six weeks of treatment (49.82±16.82, 42.66±18.75) and also after a three-month follow-up (50.94±16.27, 41.66±17.58) ( P>0.05). There were no significant differences of gait spatiotemporal symmetry ratios including step symmetry, stance symmetry, swing symmetry and overall temporal symmetry between the two groups after six weeks of treatment and also at three-month follow-up ( P>0.05).

Conclusions:

This study did not confirm that the effect of gait training combined with compelled body weight shift therapy was better than gait training alone on improving velocity and gait symmetry in patients with chronic stroke.

Gait outcomes after additional backward walking training in patients with stroke: a randomized controlled trial

Objective: To examine the effectiveness of additional backward walking training on gait outcome of patients post stroke.

Design: Randomized controlled trial.

Setting: Medical centre.

Subjects: Twenty-five subjects with stroke, who were lower extremity Brunnstrom motor recovery stage at 3 or 4 and were able to walk 11 m with or without a walking aid or orthosis, randomly allocated to two groups, control (n = 12) and experimental (n = 13).

Interventions: Subjects in both groups participated in 40 min of conventional training programme three times a week for three weeks. Subjects in experimental group received additional 30 min of backward walking training for three weeks at a frequency of three times per week.

Main measures: Gait was measured using the Stride Analyzer. Gait parameters of interest were walking speed, cadence, stride length, gait cycle and symmetry index. Measures were made at baseline before commencement of training (pre-training) and at the end of the three-week training period (post-training).

Results: After a three-week training period, subjects in experimental group showed more improvement than those in control group for walking speed (change score: 8.609 ± 6.95 versus 3.659 ± 2.92, p-value = 0.032), stride length (change score: 0.0909 ± 0.076 versus 0.00649 ± 0.078, p-value = 0.006), and symmetry index (change score: 44.079 ± 53.29 versus 5.309 ± 13.91, p-value = 0.018).

Conclusions: This study demonstrated that asymmetric gait pattern in patients post stroke could be improved from receiving additional backward walking therapy.

The effect of early aerobic training on independence six months post stroke

Objective: To investigate whether early aerobic training has a beneficial effect on stroke patients' independence in daily and social activities six months after the event.

Design: Randomized clinical trial.

Setting: Rehabilitation unit.

Subjects: Ninety-two patients after a first stroke. Interventions: Forty-six patients participated in an eight-week programme of aerobic training, using a leg cycle ergometer.

Main outcome measures: Frenchay Activities Index (FAI) measured twice, at entry to programme (pre-event score) and six months after the onset of the event.

Results: Despite the significant improvement of study group patients' functional abilities immediately after the intervention compared with controls, no significant difference was found in FAI mean score between groups six months post event. An interaction effect was noted between event severity, intervention and FAI total score. Mean FAI score declined significantly less in the less severely impaired study group patients.

Conclusions: Early, moderately intense aerobic training has no direct impact on independence in daily and social activities as measured by FAI total score six months after a stroke.

Timing, Intensity, and Duration of Rehabilitation for Hip Fracture and Stroke: Report of a Workshop at the National Center for Medical Rehabilitation Research

This article summarizes the proceedings of an NIH workshop on timing, intensity, and duration of rehabilitation for acute stroke and hip fracture. Participants concentrated on methodological issues facing investigators and suggested priorities for future research in this area.

Potential contributions of training intensity on locomotor performance in individuals with chronic stroke

BACKGROUND AND PURPOSE

Many interventions can improve walking ability of individuals with stroke, although the training parameters that maximize recovery are not clear. For example, the contribution of training intensity has not been well established and may contribute to the efficacy of many locomotor interventions. The purpose of this preliminary study was to evaluate the effects of locomotor training intensity on walking outcomes in individuals with gait deficits poststroke.

METHODS

Using a randomized cross-over design, 12 participants with chronic stroke (>6-month duration) performed either high-intensity (70%-80% of heart rate reserve; n = 6) or low-intensity (30%-40% heart rate reserve; n = 6) locomotor training for 12 or fewer sessions over 4 to 5 weeks. Four weeks following completion, the alternate training intervention was performed. Training intensity was manipulated by adding loads or applying resistance during walking, with similar speeds, durations, and amount of stepping practice between conditions.

RESULTS

Greater increases in 6-Minute Walk Test performance were observed following high-intensity training compared with low-intensity training. A significant interaction of intensity and order was also observed for 6-Minute Walk Test and peak treadmill speed, with the largest changes in those who performed high-intensity training first. Moderate correlations were observed between locomotor outcomes and measures of training intensity.

CONCLUSION

This study provides the first evidence that the intensity of locomotor practice may be an important independent determinant of walking outcomes poststroke. In the clinical setting, the intensity of locomotor training can be manipulated in many ways, although this represents only 1 parameter to consider.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, http://links.lww.com/JNPT/A90).

A comparison of the effects of visual deprivation and regular body weight support treadmill training on improving over-ground walking of stroke patients: a multiple baseline single subject design

The body-weight-support treadmill (BWST) is commonly used for gait rehabilitation, but other forms of BWST are in development, such as visual-deprivation BWST (VDBWST). In this study, we compare the effect of VDBWST training and conventional BWST training on spatiotemporal gait parameters for three individuals who had hemiparetic strokes. We used a single-subject experimental design, alternating multiple baselines across the individuals. We recruited three individuals with hemiparesis from stroke; two on the left side and one on the right. For the main outcome measures we assessed spatiotemporal gait parameters using GAITRite, including: gait velocity; cadence; step time of the affected side (STA); step time of the non-affected side (STN); step length of the affected side (SLA); step length of the non-affected side (SLN); step-time asymmetry (ST-asymmetry); and step-length asymmetry (SL-asymmetry). Gait velocity, cadence, SLA, and SLN increased from baseline after both interventions, but STA, ST-asymmetry, and SL-asymmetry decreased from the baseline after the interventions. The VDBWST was significantly more effective than the BWST for increasing gait velocity and cadence and for decreasing ST-asymmetry. VDBWST is more effective than BWST for improving gait performance during the rehabilitation for ground walking.

Task-Oriented Aerobic Exercise in Chronic Hemiparetic Stroke: Training Protocols and Treatment Effects

Stroke is the leading cause of disability in older Americans. Each year 750,000 Americans suffer a stroke, two thirds of whom are left with neurological deficits that persistently impair function. Principal among them is hemiparetic gait that limits mobility and increases fall risk, promoting a sedentary lifestyle. These events propagate disability by physical deconditioning and "learned non-use," with further functional declines accelerated by the sarcopenia and fitness decrements of advancing age. Conventional rehabilitation care typically provides little or no structured therapeutic exercise beyond the subacute stroke recovery period, based on natural history studies showing little or no further functional motor recovery beyond 6 months after stroke. Emerging evidence suggests that new models of task-oriented exercise have the potential to improve motor function even years after stroke. This article presents treadmill as a task-oriented training paradigm to optimize locomotor relearning while eliciting cardiovascular conditioning in chronic stroke patients. Protocols for exercise testing and longitudinal aerobic training progression are presented that provide fundamental formulas that safely approach the complex task of customizing aerobic training to gait deficit severity in the high CVD risk stroke population. The beneficial effects of 6 months task-oriented treadmill exercise on cardiovascular-metabolic fitness, energy cost of hemiparetic gait, ADL mobility task performance, and leg strength are discussed with respect to the central and peripheral neuromuscular adaptations targeted by the training. Collectively, these findings constitute one initial experience in a much broader neuroscience and exercise rehabilitation development of task-oriented training paradigms that offer a multisystems approach to improving both neurological and cardiovascular health outcomes in the chronic stroke population.

Motor learning during poststroke gait rehabilitation: a case study

INTRODUCTION

To develop more effective gait rehabilitation strategies, it is important to understand the time course of motor learning that underlies improvements achieved with gait training. The purpose of this case study was to evaluate motor learning through the measurement of within-session and across-session changes in gait biomechanics during the first and sixth weeks of a 6-week clinical gait training program.

CASE DESCRIPTION

A 47-year-old man with poststroke left hemiparesis participated in the study (15.5 months poststroke, lower extremity Fugl-Meyer score of 12).

INTERVENTION

The subject participated in 6 weeks of training with 3 sessions per week, comprising fast treadmill walking and functional electrical stimulation to plantar and dorsiflexors. In one training session during the first and sixth weeks, paretic propulsion and swing phase knee flexion were measured during a pretest (before the training session), posttest (after the training session), and retention test (48 hours after training).

OUTCOMES

After 6 week of training, the subject's gait speed increased from 0.38 to 0.57 m/s; there was a 55.4% improvement in paretic propulsion and 25% increase in swing phase knee flexion. Examination of change scores revealed greater within-session gains and greater retention during the first versus sixth weeks of gait training for both paretic propulsion and knee flexion.

DISCUSSION

We demonstrate the feasibility and advantage of using within- and across-session changes for evaluating motor learning during clinical gait rehabilitation. An understanding of the time course of motor learning that underlies gait training can guide the development of novel strategies and dosing regimens to increase the efficacy of each session of gait rehabilitation.

VIDEO ABSTRACT AVAILABLE

(See Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A72, for more insights from the authors.).

Cardiovascular response during submaximal underwater treadmill exercise in stroke patients

Objective

To evaluate the cardiovascular response during head-out water immersion, underwater treadmill gait, and land treadmill gait in stroke patients.

Methods

Ten stroke patients were recruited for underwater and land treadmill gait sessions. Each session was 40 minutes long; 5 minutes for standing rest on land, 5 minutes for standing rest in water or on treadmill, 20 minutes for treadmill walking in water or on land, 5 minutes for standing rest in water or on treadmill, and 5 minutes for standing rest on land. Blood pressure (BP) and heart rate (HR) were measured during each session. In order to estimate the cardiovascular workload and myocardial oxygen demand, the rate pressure product (RPP) value was calculated by multiplying systolic BP (SBP) by HR.

Results

SBP, DBP, mean BP (mBP), and RPP decreased significantly after water immersion, but HR was unchanged. During underwater and land treadmill gait, SBP, mBP, DBP, RPP, and HR increased. However, the mean maximum increases in BP, HR and RPP of underwater treadmill walking were significantly lower than that of land treadmill walking.

Conclusion

Stroke patients showed different cardiovascular responses during water immersion and underwater gait as opposed to standing and treadmill-walking on land. Water immersion and aquatic treadmill gait may reduce the workload of the cardiovascular system. This study suggested that underwater treadmill may be a safe and useful option for cardiovascular fitness and early ambulation in stroke rehabilitation.

Walking cadence and mortality among community-dwelling older adults

BACKGROUND

Older adults are encouraged to walk ≥100 steps∙minute(-1) for moderate-intensity physical activity (i.e., brisk walking). It is unknown if the ability to walk ≥100 steps∙minute(-1) predicts mortality.

OBJECTIVE

To determine if the ability to walk ≥100 steps∙minute(-1) predicts mortality among older adults.

DESIGN, SETTING, AND PATIENTS

A population-based cohort study among 5,000 older adults from the Third National Health and Nutrition Survey (NHANES III; 1988-1994). Vital status and cause of death were collected through December 31, 2006. Median follow-up was 13.4 years. Average participant age was 70.6 years.

MEASUREMENTS

Walking cadence (steps∙minute(-1)) was calculated using a timed 2.4-m walk. Walking cadence was dichotomized at 100 steps∙minute(-1) (≥100 steps∙minute(-1) versus <100 steps∙minute(-1)) to demarcate the lower threshold of absolutely defined moderate-intensity physical activity. Walking cadence was also analyzed as a continuous variable. Predicted survival was compared between walking cadence and gait speed. The primary outcome was all-cause mortality. Secondary outcomes included cardiovascular-specific and cancer-specific mortality and mortality from other causes.

RESULTS

Among 5,000 participants, 3,039 (61 %) walked ≥100 steps∙minute(-1). During follow-up, 3,171 subjects died. In multivariable-adjusted analysis, ability to walk ≥100 steps∙minute(-1) predicted a 21 % reduction in all-cause mortality (hazard ratio [HR], 0.79; 95 % confidence interval [95 % CI], 0.71-0.89, p < 0.001). Each ten-step increase in walking cadence predicted a 4 % reduction in all-cause mortality (HR, 0.96, [0.94-0.98], p < 0.001). In secondary analyses, ability to walk ≥100 steps∙minute(-1) predicted reductions in cardiovascular-specific mortality (HR, 0.79 [0.67-0.92], p = 0.002), cancer-specific mortality (HR, 0.76 [0.58-0.99], p = 0.050), and mortality from other causes (HR, 0.82 [0.68-0.97], p = 0.025). Predicted survival, adjusted for age and sex, was not different using walking cadence versus gait speed.

LIMITATIONS

Walking cadence was a cross-sectional measurement.

CONCLUSIONS

The ability to walk ≥100 steps∙minute(-1) predicts a reduction in mortality among a sample of community-dwelling older adults.

Does the speed of the treadmill influence the training effect in people learning to walk after stroke? A double-blind randomized controlled trial

OBJECTIVE

To compare the effectiveness of high-speed treadmill training and progressive treadmill training for stroke patients.

DESIGN

A double-blind, randomized controlled trial.

SETTING

Inpatient rehabilitation hospital.

PARTICIPANTS

A total of 61 ambulatory stroke patients.

INTERVENTIONS

Patients in both groups underwent treadmill training for 30 minutes with conventional intervention. The progressive training group (n = 31) was trained to walk on a treadmill with a stepwise increase of speed over the treatment period. The high-speed training group (n = 30) trained to begin at 1.2-1.3 m/s, which is faster than the mean speed of stroke patients. All participants underwent 20 training sessions for five weeks.

MAIN MEASURES

Timed up-and-go test, 10-m walk test, 6-minute walk test, and both step lengths and cadence.

RESULTS

There were significant improvements in the results of the timed up-and-go test (-1.96 vs. -5.02 seconds), 10-m walk test (0.30 vs. 0.47 m/s), 6-minute walk test (38.35 vs. 64.40 m), and in the step length of the affected side (0.14 vs. 0.19 m) and the unaffected side (0.10 vs. 0.12 m) in the high-speed training group compared with those in the progressive training group (p < 0.05). Step width was not changed in either group (p > 0.05).

CONCLUSION

These results suggest that high-speed training is an effective method for improving the walking ability of stroke patients.

Agreement between the spatio-temporal gait parameters from treadmill-based photoelectric cell and the instrumented treadmill system in healthy young adults and stroke patients

Background

Treadmill gait analysis was more advantageous than over-ground walking because it allowed continuous measurements of the gait parameters. The purpose of this study was to investigate the concurrent validity and the test-retest reliability of the OPTOGait photoelectric cell system against the treadmill-based gait analysis system by assessing spatio-temporal gait parameters.

Material/Methods

Twenty-six stroke patients and 18 healthy adults were asked to walk on the treadmill at their preferred speed. The concurrent validity was assessed by comparing data obtained from the 2 systems, and the test-retest reliability was determined by comparing data obtained from the 1^st and the 2^nd session of the OPTOGait system.

Results

The concurrent validity, identified by the intra-class correlation coefficients (ICC [2, 1]), coefficients of variation (CV_ME), and 95% limits of agreement (LOA) for the spatial-temporal gait parameters, were excellent but the temporal parameters expressed as a percentage of the gait cycle were poor. The test-retest reliability of the OPTOGait System, identified by ICC (3, 1), CV_ME, 95% LOA, standard error of measurement (SEM), and minimum detectable change (MDC₉₅%) for the spatio-temporal gait parameters, was high.

Conclusions

These findings indicated that the treadmill-based OPTOGait System had strong concurrent validity and test-retest reliability. This portable system could be useful for clinical assessments.

Cardiopulmonary responses to robotic end-effector-based walking and stair climbing

BACKGROUND

A recently developed robotic end-effector device (G-EO system, Reha Technology AG) can simulate walking and stair climbing. This approach has the potential to promote cardiovascular exercise training during rehabilitation. The aim of this study was to characterise cardiopulmonary responses of end-effector-based exercise in able-bodied subjects and to evaluate the feasibility of intensity-guided exercise testing.

METHODS

Five healthy subjects aged 33.7 ± 8.8 years (mean ± SD) performed a constant load test and an intensity-guided incremental exercise test. The outcome measures were steady-state and peak cardiopulmonary performance parameters including oxygen uptake (VO2) and heart rate (HR).

RESULTS

Passive end-effector-based stair climbing (VO2=13.6 ± 4.5 mL/min/kg, HR=95 ± 23 beats/min) showed considerably lower cardiopulmonary responses compared to reference data (VO2=33.5 ± 4.8 mL/min/kg, HR=159 ± 15 beats/min). Peak performance parameters during intensity-guided incremental exercise testing were: VO2=35.8 ± 5.1 mL/min/kg and HR=161 ± 27 beats/min, corresponding to a relative VO2=76.0 ± 18.7% of predicted aerobic capacity and a relative HR=87.3 ± 14.5% of age-predicted HR maximum.

CONCLUSION

End-effector-based exercise is a promising method for the implementation of cardiovascular exercise. Although end-effector-based stair climbing evoked lower cardiopulmonary responses than conventional stair climbing, active contribution during exercise elicited substantial cardiopulmonary responses within recommended ranges for aerobic training.

Molecular mechanisms of treadmill therapy on neuromuscular atrophy induced via botulinum toxin A

Botulinum toxin A (BoNT-A) is a bacterial zinc-dependent endopeptidase that acts specifically on neuromuscular junctions. BoNT-A blocks the release of acetylcholine, thereby decreasing the ability of a spastic muscle to generate forceful contraction, which results in a temporal local weakness and the atrophy of targeted muscles. BoNT-A-induced temporal muscle weakness has been used to manage skeletal muscle spasticity, such as poststroke spasticity, cerebral palsy, and cervical dystonia. However, the combined effect of treadmill exercise and BoNT-A treatment is not well understood. We previously demonstrated that for rats, following BoNT-A injection in the gastrocnemius muscle, treadmill running improved the recovery of the sciatic functional index (SFI), muscle contraction strength, and compound muscle action potential (CMAP) amplitude and area. Treadmill training had no influence on gastrocnemius mass that received BoNT-A injection, but it improved the maximal contraction force of the gastrocnemius, and upregulation of GAP-43, IGF-1, Myo-D, Myf-5, myogenin, and acetylcholine receptor (AChR) subunits α and β was found following treadmill training. Taken together, these results suggest that the upregulation of genes associated with neurite and AChR regeneration following treadmill training may contribute to enhanced gastrocnemius strength recovery following BoNT-A injection.

Generalization of improved step length symmetry from treadmill to overground walking in persons with stroke and hemiparesis

OBJECTIVES

Determine whether adaptation to a swing phase perturbation during gait transferred from treadmill to overground walking, the rate of overground deadaptation, and whether overground aftereffects improved step length asymmetry in persons with hemiparetic stroke and gait asymmetry.

METHODS

Ten participants with stroke and hemiparesis and 10 controls walked overground on an instrumented gait mat, adapted gait to a swing phase perturbation on a treadmill, then walked overground on the gait mat again. Outcome measures, primary: overground step length symmetry, rates of treadmill step length symmetry adaptation and overground step length symmetry deadaptation; secondary: overground gait velocity, stride length, and stride cycle duration.

RESULTS

Step length symmetry aftereffects generalized to overground walking and adapted at a similar rate on the treadmill in both groups. Aftereffects decayed at a slower rate overground in participants with stroke and temporarily improved overground step length asymmetry. Both groups' overground gait velocity increased post adaptation due to increased stride length and decreased stride duration.

CONCLUSIONS

Stroke and hemiparesis do not impair generalization of step length symmetry changes from adapted treadmill to overground walking, but prolong overground aftereffects.

SIGNIFICANCE

Motor adaptation during treadmill walking may be an effective treatment for improving overground gait asymmetries post-stroke.

Randomized Trial of Treadmill Training to Improve Walking in Community-Dwelling People after Stroke: The AMBULATE Trial

Background

Residual walking deficits are common in community-dwelling people after stroke.

Aims

The aim of this study was to determine if a four-month treadmill and overground walking program is more effective than a two-month program, compared with control, at improving walking in community-dwelling people with stroke who walk slowly.

Method

A three-arm randomized trial with concealed allocation, assessor blinding, and intention-to-treat analysis involving 102 people with stroke living in the community who walked slowly was undertaken. Experimental group 1 undertook 30 min of treadmill and overground walking thrice per week for four-months, experimental group 2 undertook training for two-months, while the control group had no intervention. The primary outcome was walking measured as the distance covered during the six-min walk test. Other outcomes were walking speed, step length and cadence, health status, community participation, self-efficacy and falls.

Results

By two-months, the experimental groups, who were both undergoing training, had improved their six-min walk distance compared with the control group. The four-month training group continued training beyond two-months and improved further so that by four months they walked 38 m (95% confidence interval 15–60) more than the control group and 29 m (95% confidence interval 4–53) more than the two-month training group. However, by 12 months, well after the cessation of training, both experimental groups had returned to near baseline levels, and there was no difference between the groups.

Conclusion

Four months of treadmill training results in better walking. However, these effects disappear once training ceases. Therefore, training should be ongoing.

Effects of repeated treadmill testing and electrical stimulation on post-stroke gait kinematics

Improvements in task performance due to repeated testing have previously been documented in healthy and patient populations. The existence of a similar change in performance due to repeated testing has not been previously investigated at the level of gait kinematics in the post-stroke population. The presence of such changes may define the number of testing sessions necessary for measuring a stable baseline of pre-training gait performance, which is a necessary prerequisite for determining the effectiveness of gait interventions. Considering the emergence of treadmills as a popular tool for gait evaluation and retraining and the common addition of functional electrical stimulation (FES) to gait retraining protocols, the stability of gait kinematics during the repeated testing of post-stroke individuals on a treadmill, either with or without FES, needs to be determined. Nine individuals (age: 58.1±7.3 years), with hemi-paresis secondary to a stroke (onset: 7.3±6.0 years) participated in this study. An 8-camera motion analysis system was used to measure sagittal plane knee and ankle joint kinematics. Gait kinematics were compared across two (N=9) and five (N=5) testing sessions. No consistent changes in knee or ankle kinematics were observed during repeated testing. These findings indicate that clinicians and researchers may not need to spend valuable time and resources performing multiple testing and acclimatization sessions when assessing baseline gait kinematics in the post-stroke population for use in determining the effectiveness of gait interventions.

Oxygen consumption, oxygen cost, heart rate, and perceived effort during split-belt treadmill walking in young healthy adults

During split-belt treadmill walking the speed of the treadmill under one limb is faster than the belt under the contralateral limb. This unique intervention has shown evidence of acutely improving gait impairments in individuals with neurologic impairment such as stroke and Parkinson's disease. However, oxygen use, heart rate and perceived effort associated with split-belt treadmill walking are unknown and may limit the utility of this locomotor intervention. To better understand the intensity of this new intervention, this study was undertaken to examine the oxygen consumption, oxygen cost, heart rate, and rating of perceived exertion associated with split-belt treadmill walking in young healthy adults. Fifteen participants completed three sessions of treadmill walking: slow speed with belts tied, fast speed with belts tied, and split-belt walking with one leg walking at the fast speed and one leg walking at the slow speed. Oxygen consumption, heart rate, and rating of perceived exertion were collected during each walking condition and oxygen cost was calculated. Results revealed that oxygen consumption, heart rate, and perceived effort associated with split-belt walking were higher than slow treadmill walking, but only oxygen consumption was significantly lower during both split-belt walking than fast treadmill walking. Oxygen cost associated with slow treadmill walking was significantly higher than fast treadmill walking. These findings have implications for using split-belt treadmill walking as a rehabilitation tool as the cost associated with split-belt treadmill walking may not be higher or potentially more detrimental than that associated with previously used treadmill training rehabilitation strategies.

Changes in fat mass in stroke survivors: a systematic review

BACKGROUND

Stroke survivors have less muscle mass in their paretic limbs compared with nonparetic limbs, which may or may not be accompanied by changes in regional and/or whole body fat mass.

AIM

To examine the current evidence regarding differences in regional fat mass between paretic and nonparetic limbs and changes in whole body fat mass over time in stroke survivors.

METHODS

A systematic search of relevant databases. Studies measuring whole body or regional fat mass using dual-energy X-ray absorpiometry, computed tomography, or magnetic resonance imaging were included.

RESULTS

Eleven trials were identified. Fat mass differences between paretic and nonparetic limbs and change in fat mass over time were not consistent. Meta-analyses were conducted using dual-energy X-ray absorpiometry-derived data from 10 trials (n = 324). There were no differences in fat mass between paretic and nonparetic legs (pooled mean difference 31·4 g, 95% confidence interval -33·9 to 96·6, P = 0·35), and slightly greater fat mass in the paretic arms compared with nonparetic arms (pooled mean difference 84·0 g, 95% confidence interval 30·7 to 137·3, P = 0·002). Whole body fat mass did not increase significantly between one-month and six-months poststroke (pooled mean difference 282·3 g, 95% confidence interval -824·4 to 1389, P = 0·62), but there was an increase between six- and 12 months poststroke (pooled mean difference 1935 g, 95% confidence interval 1031 to 2839, P < 0·001).

CONCLUSIONS

There were inconsistent findings regarding changes in fat mass after stroke. Large, well-designed studies are required to further investigate the impact of body composition changes on the health of stroke survivors.

Impact of treadmill exercise on efficacy expectations, physical activity, and stroke recovery

Stroke survivors are at high risk for cardiovascular mortality which can be in part mitigated by increasing physical activity. Self-efficacy for exercise is known to play a role in adoption of exercise behaviors. This study examines self-reported psychological outcomes in a group of 64 stroke survivors randomized to either a 6-month treadmill training program or a stretching program. Results indicated that, regardless of group, all study participants experienced increased self-efficacy (F = 2.95, p = .09) and outcome expectations for exercise (F = 13.23, p < 0.001) and improvements in activities of daily living as reported on the Stroke Impact Scale (F = 10.97, p = .002). No statistically significant between-group differences were noted, possibly because of the fact that specific interventions designed to enhance efficacy beliefs were not part of the study. Theoretically based interventions should be tested to clarify the role of motivation and potential influence on exercise and physical activity in the stroke survivor population.

Use of visual and proprioceptive feedback to improve gait speed and spatiotemporal symmetry following chronic stroke: a case series

BACKGROUND AND PURPOSE

Persistent deficits in gait speed and spatiotemporal symmetry are prevalent following stroke and can limit the achievement of community mobility goals. Rehabilitation can improve gait speed, but has shown limited ability to improve spatiotemporal symmetry. The incorporation of combined visual and proprioceptive feedback regarding spatiotemporal symmetry has the potential to be effective at improving gait.

CASE DESCRIPTION

A 60-year-old man (18 months poststroke) and a 53-year-old woman (21 months poststroke) each participated in gait training to improve gait speed and spatiotemporal symmetry. Each patient performed 18 sessions (6 weeks) of combined treadmill-based gait training followed by overground practice. To assist with relearning spatiotemporal symmetry, treadmill-based training for both patients was augmented with continuous, real-time visual and proprioceptive feedback from an immersive virtual environment and a dual belt treadmill, respectively.

OUTCOMES

Both patients improved gait speed (patient 1: 0.35 m/s improvement; patient 2: 0.26 m/s improvement) and spatiotemporal symmetry. Patient 1, who trained with step-length symmetry feedback, improved his step-length symmetry ratio, but not his stance-time symmetry ratio. Patient 2, who trained with stance-time symmetry feedback, improved her stance-time symmetry ratio. She had no step-length asymmetry before training.

DISCUSSION

Both patients made improvements in gait speed and spatiotemporal symmetry that exceeded those reported in the literature. Further work is needed to ascertain the role of combined visual and proprioceptive feedback for improving gait speed and spatiotemporal symmetry after chronic stroke.

Interventions for coordination of walking following stroke: systematic review

Impairments in gait coordination may be a factor in falls and mobility limitations after stroke. Therefore, rehabilitation targeting gait coordination may be an effective way to improve walking post-stroke. This review sought to examine current treatments that target impairments of gait coordination, the theoretical basis on which they are derived and the effects of such interventions. Few high quality RCTs with a low risk of bias specifically targeting and measuring restoration of coordinated gait were found. Consequently, we took a pragmatic approach to describing and quantifying the available evidence and included non-randomised study designs and limited the influence of heterogeneity in experimental design and control comparators by restricting meta-analyses to pre- and post-test comparisons of experimental interventions only. Results show that physiotherapy interventions significantly improved gait function and coordination. Interventions involving repetitive task-specific practice and/or auditory cueing appeared to be the most promising approaches to restore gait coordination. The fact that overall improvements in gait coordination coincided with increased walking speed lends support to the hypothesis that targeting gait coordination gait may be a way of improving overall walking ability post-stroke. However, establishing the mechanism for improved locomotor control requires a better understanding of the nature of both neuroplasticity and coordination deficits in functional tasks after stroke. Future research requires the measurement of impairment, activity and cortical activation in an effort to establish the mechanism by which functional gains are achieved.

Poststroke hemiparesis impairs the rate but not magnitude of adaptation of spatial and temporal locomotor features

BACKGROUND

Persons with stroke and hemiparesis walk with a characteristic pattern of spatial and temporal asymmetry that is resistant to most traditional interventions. It was recently shown in nondisabled persons that the degree of walking symmetry can be readily altered via locomotor adaptation. However, it is unclear whether stroke-related brain damage affects the ability to adapt spatial or temporal gait symmetry.

OBJECTIVE

Determine whether locomotor adaptation to a novel swing phase perturbation is impaired in persons with chronic stroke and hemiparesis.

METHODS

Participants with ischemic stroke (14) and nondisabled controls (12) walked on a treadmill before, during, and after adaptation to a unilateral perturbing weight that resisted forward leg movement. Leg kinematics were measured bilaterally, including step length and single-limb support (SLS) time symmetry, limb angle center of oscillation, and interlimb phasing, and magnitude of "initial" and "late" locomotor adaptation rates were determined.

RESULTS

All participants had similar magnitudes of adaptation and similar initial adaptation rates both spatially and temporally. All 14 participants with stroke and baseline asymmetry temporarily walked with improved SLS time symmetry after adaptation. However, late adaptation rates poststroke were decreased (took more strides to achieve adaptation) compared with controls.

CONCLUSIONS

Mild to moderate hemiparesis does not interfere with the initial acquisition of novel symmetrical gait patterns in both the spatial and temporal domains, though it does disrupt the rate at which "late" adaptive changes are produced. Impairment of the late, slow phase of learning may be an important rehabilitation consideration in this patient population.