Rehabilitation of gait speed after stroke: a critical review of intervention approaches

We Will, We Will Shock You: Adaptive Versus Conventional Functional Electrical Stimulation in Individuals Post-Stroke

Functional electrical stimulation (FES) is often used in poststroke gait rehabilitation to address decreased walking speed, foot drop, and decreased forward propulsion. However, not all individuals experience clinically meaningful improvements in gait function with stimulation. Previous research has developed adaptive functional electrical stimulation (AFES) systems that adjust stimulation timing and amplitude at every stride to deliver optimal stimulation. The purpose of this work was to determine the effects of a novel AFES system on functional gait outcomes and compare them to the effects of the existing FES system. Twenty-four individuals with chronic poststroke hemiparesis completed 64-min walking trials on an adaptive and fixed-speed treadmill with no stimulation, stimulation from the existing FES system, and stimulation from the AFES system. There was no significant effect of stimulation condition on walking speed, peak dorsiflexion angle, or peak propulsive force. Walking speed was significantly faster and peak propulsive force was significantly larger on the adaptive treadmill (ATM) than the fixed-speed treadmill (both p < 0.0001). Dorsiflexor stimulation timing was similar between stimulation conditions, but plantarflexor stimulation timing was significantly improved with the AFES system compared to the FES system (p = 0.0059). Variability between and within subjects was substantial, and some subjects experienced clinically meaningful improvements in walking speed, peak dorsiflexion angle, and peak propulsive force. However, not all subjects experienced benefits, suggesting that further research to characterize which subjects exhibit the best instantaneous response to FES is needed to optimize poststroke gait rehabilitation using FES.

Passive-dynamic ankle-foot orthoses change post-stroke lower extremity constituent work profile

Stiffness-customized passive-dynamic ankle-foot orthoses (PD-AFOs) have been shown to reduce the mechanical cost of transport (COT) of individuals post-stroke. However, the mechanisms underlying this reduced COT are unknown. Therefore, this study aimed to identify the factors driving COT reduction with PD-AFO use for individuals post-stroke. Results showed that changes in limb work were strongly correlated to changes in COT with the PD-AFO compared to No AFO in the paretic (tau = 0.637, p < 0.001) and non-paretic (tau = 0.621, p < 0.001) limbs. There was also a strong correlation between changes in limb work and changes in COT compared to SOC AFO in the paretic (tau = 0.569, p < 0.001) and non-paretic (tau = 0.503, p = 0.003) limbs. Conversely, changes in stride length and changes in COT were not correlated. Changes in COT between No AFO and PD-AFO were moderately correlated to the number of constituents that performed less mechanical work for both the paretic (tau = -0.462, p = 0.009) and non-paretic (tau = -0.402, p = 0.025) limbs. Compared to walking with SOC AFOs, there was a moderate correlation between COT and the number of constituents in the paretic limb (tau = -0.458, p = 0.011) but not the non-paretic limb (tau = -0.247, p = 0.173). These findings indicate that PD-AFOs reduce COT primarily through small changes in work across many lower limb constituents. Understanding how COT reduction occurs can help optimize PD-AFO design and possibly other rehabilitation interventions for individuals post-stroke.

Customized passive-dynamic ankle-foot orthoses can improve walking economy and speed for many individuals post-stroke

BACKGROUND

Passive-dynamic ankle-foot orthoses (PD-AFOs) are often prescribed to address plantar flexor weakness during gait, which is commonly observed after stroke. However, limited evidence is available to inform the prescription guidelines of PD-AFO bending stiffness. This study assessed the extent to which PD-AFOs customized to match an individual's level of plantar flexor weakness influence walking function, as compared to No AFO and their standard of care (SOC) AFO.

METHODS

Mechanical cost-of-transport, self-selected walking speed, and key biomechanical variables were measured while individuals greater than six months post-stroke walked with No AFO, with their SOC AFO, and with a stiffness-customized PD-AFO. Outcomes were compared across these conditions using a repeated measures ANOVA or Friedman test (depending on normality) for group-level analysis and simulation modeling analysis for individual-level analysis.

RESULTS

Twenty participants completed study activities. Mechanical cost-of-transport and self-selected walking speed improved with the stiffness-customized PD-AFOs compared to No AFO and SOC AFO. However, this did not result in a consistent improvement in other biomechanical variables toward typical values. In line with the heterogeneous nature of the post-stroke population, the response to the PD-AFO was highly variable.

CONCLUSIONS

Stiffness-customized PD-AFOs can improve the mechanical cost-of-transport and self-selected walking speed in many individuals post-stroke, as compared to No AFO and participants' standard of care AFO. This work provides initial efficacy data for stiffness-customized PD-AFOs in individuals post-stroke and lays the foundation for future studies to enable consistently effective prescription of PD-AFOs for patients post-stroke in clinical practice.

TRIAL REGISTRATION

NCT04619043.

The effectiveness of bodyweight-supported treadmill training in stroke patients: randomized controlled trial

OBJECTIVE

This study aimed to assess the impact of conventional rehabilitation (CR) and the combination of bodyweight-supported treadmill training (BWSTT) with CR on walking speed, endurance, balance, mobility, and the quality of life in stroke survivors.

METHOD

In this prospective, randomized, controlled, and single-blind study, 30 stroke patients were included (ClinicalTrials.gov registration number: NCT04597658 date: October 22, 2020). These patients were divided into two groups: (1) CR only (control group, n = 14) and (2) CR with BWSTT (experimental group, n = 16). Both groups received CR for 3 consecutive weeks, 5 days a week, for 30 min each day. The experimental group received an additional 30 min of BWSTT per session. Patients were evaluated using the 10-m walk test (10MWT), the six-minute walk test (6MWT), the Tinetti Balance and Gait Assessment Score, the Timed Up and Go (TUG) test, the Rivermead Mobility Index (RMI), and the Stroke-Specific Quality of Life Scale (SS-QOL) before and after the intervention.

RESULTS

Both groups showed significant improvements across all scales after the intervention. The BWSTT group exhibited particularly noteworthy enhancements in comfortable 10MWT and TUG scores (p = 0.043 and p = 0.025, respectively) compared to the CR group post-intervention.

CONCLUSION

In conclusion, a holistic approach combining conventional physiotherapy with overground gait training can enhance various aspects of mobility. This approach offers a cost-effective and equipment-free alternative to BWSTT and necessitates specialized treadmill and bodyweight support systems, incurring higher costs. However, using BWSTT as a co-therapy therapy can be costly but provides additional benefits for enhancing functional mobility.

Adaptive Functional Electrical Stimulation Delivers Stimulation Amplitudes Based on Real-Time Gait Biomechanics

Functional electrical stimulation (FES) is often used in poststroke gait rehabilitation to decrease foot drop and increase forward propulsion. However, not all stroke survivors experience clinically meaningful improvements in gait function following training with FES. The purpose of this work was to develop and validate a novel adaptive FES (AFES) system to improve dorsiflexor (DF) and plantarflexor (PF) stimulation timing and iteratively adjust the stimulation amplitude at each stride based on measured gait biomechanics. Stimulation timing was determined by a series of bilateral footswitches. Stimulation amplitude was calculated based on measured dorsiflexion angle and peak propulsive force, where increased foot drop and decreased paretic propulsion resulted in increased stimulation amplitudes. Ten individuals with chronic poststroke hemiparesis walked on an adaptive treadmill with adaptive FES for three 2-min trials. Stimulation was delivered at the correct time to the dorsiflexor muscles during 95% of strides while stimulation was delivered to the plantarflexor muscles at the correct time during 84% of strides. Stimulation amplitudes were correctly calculated and delivered for all except two strides out of nearly 3000. The adaptive FES system responds to real-time gait biomechanics as intended, and further individualization to subject-specific impairments and rehabilitation goals may lead to improved rehabilitation outcomes.

Simultaneous high-definition transcranial direct current stimulation and robot-assisted gait training in stroke patients

This study investigates whether simultaneous high-definition transcranial direct current stimulation (HD-tDCS) enhances the effects of robot-assisted gait training in stroke patients. Twenty-four participants were randomly allocated to either the robot-assisted gait training with real HD-tDCS group (real HD-tDCS group) or robot-assisted gait training with sham HD-tDCS group (sham HD-tDCS group). Over four weeks, both groups completed 10 sessions. The 10 Meter Walk Test, Timed Up and Go, Functional Ambulation Category, Functional Reach Test, Berg Balance Scale, Dynamic Gait Index, Fugl-Meyer Assessment, and Korean version of the Modified Barthel Index were conducted before, immediately after, and one month after the intervention. The real HD-tDCS group showed significant improvements in the 10 Meter Walk Test, Timed Up and Go, Functional Reach Test, and Berg Balance Scale immediately and one month after the intervention, compared with before the intervention. Significant improvements in the Dynamic Gait Index and Fugl-Meyer Assessment were also observed immediately after the intervention. The sham HD-tDCS group showed no significant improvements in any of the tests. Application of HD-tDCS during robot-assisted gait training has a positive effect on gait and physical function in chronic stroke patients, ensuring long-term training effects. Our results suggest the effectiveness of HD-tDCS as a complementary tool to enhance robotic gait rehabilitation therapy in chronic stroke patients.

Human Gait Entrainment to Soft Robotic Hip Perturbation During Simulated Overground Walking

Entraining human gait with a periodic mechanical perturbation has been proposed as a potentially effective strategy for gait rehabilitation, but the related studies have mostly depended on the use of a fixed-speed treadmill (FST) due to various practical constraints. However, imposing a constant treadmill speed on participants becomes a critical problem because this speed constraint prohibits the participants from adjusting the gait speed, resulting in significant alterations in natural biomechanics as the entrainment alters the stride frequency. In this study, we hypothesized that the use of a variable-speed treadmill (VST), which enables the participants to continuously adjust their speed, can improve the success rate of gait entrainment and preserve natural gait biomechanics. To test this hypothesis, we recruited 15 young and healthy adults and let them walk on a conventional FST and a self-paced VST while wearing a soft robotic hip exosuit, which applied hip flexion perturbations at various frequencies, ranging from the preferred walking frequency to a 30% increased value. Kinematics and kinetics of the participants' walking under the two treadmill conditions were measured on two separate days. Experimental results demonstrated a higher success rate of entrainment during VST walking compared to FST walking, particularly at faster perturbation frequencies. Furthermore, walking on VST facilitated the maintenance of natural biomechanics, such as stride length and normalized propulsive impulse, better than walking on FST. The observed improvement, primarily attributed to allowing an increase in walking speed following the increase in the perturbation frequency, suggests that using a self-paced VST is a viable method for exploiting the potentially beneficial therapeutic effects of entrainment in gait rehabilitation.

Walking speeds are lower for short distance and turning locomotion: Experiments and modeling in low-cost prosthesis users

Preferred walking speed is a widely-used performance measure for people with mobility issues, but is usually measured in straight line walking for fixed distances or durations, and without explicitly accounting for turning. However, daily walking involves walking for bouts of different distances and walking with turning, with prior studies showing that short bouts with at most 10 steps could be 40% of all bouts and turning steps could be 8-50% of all steps. Here, we studied walking in a straight line for short distances (4 m to 23 m) and walking in circles (1 m to 3 m turning radii) in people with transtibial amputation or transfemoral amputation using a passive ankle-foot prosthesis (Jaipur Foot). We found that the study participants' preferred walking speeds are lower for shorter straight-line walking distances and lower for circles of smaller radii, which is analogous to earlier results in subjects without amputation. Using inverse optimization, we estimated the cost of changing speeds and turning such that the observed preferred walking speeds in our experiments minimizes the total cost of walking. The inferred costs of changing speeds and turning were larger for subjects with amputation compared to subjects without amputation in a previous study, specifically, being 4x to 8x larger for the turning cost and being highest for subjects with transfemoral amputation. Such high costs inferred by inverse optimization could potentially include non-energetic costs such as due to joint or interfacial stress or stability concerns, as inverse optimization cannot distinguish such terms from true metabolic cost. These experimental findings and models capturing the experimental trends could inform prosthesis design and rehabilitation therapy to better assist changing speeds and turning tasks. Further, measuring the preferred speed for a range of distances and radii could be a more comprehensive subject-specific measure of walking performance than commonly used straight line walking metrics.

Non-invasive brain stimulation for functional recovery in animal models of stroke: A systematic review

Motor and cognitive dysfunction occur frequently after stroke, severely affecting a patient´s quality of life. Recently, non-invasive brain stimulation (NIBS) has emerged as a promising treatment option for improving stroke recovery. In this context, animal models are needed to improve the therapeutic use of NIBS after stroke. A systematic review was conducted based on the PRISMA statement. Data from 26 studies comprising rodent models of ischemic stroke treated with different NIBS techniques were included. The SYRCLE tool was used to assess study bias. The results suggest that both repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) improved overall neurological, motor, and cognitive functions and reduced infarct size both in the short- and long-term. For tDCS, it was observed that either ipsilesional inhibition or contralesional stimulation consistently led to functional recovery. Additionally, the application of early tDCS appeared to be more effective than late stimulation, and tDCS may be slightly superior to rTMS. The optimal stimulation protocol and the ideal time window for intervention remain unresolved. Future directions are discussed for improving study quality and increasing their translational potential.

How Important is Position in Adaptive Treadmill Control?

To more closely mimic overground walking, researchers are developing adaptive treadmills (ATMs) that update belt speed in real-time based on user gait mechanics. Many existing ATM control schemes are solely based on position on the belt and do not respond to changes in gait mechanics, like propulsive forces, that result in increased overground walking speed. To target natural causal mechanisms to alter speed, we developed an ATM controller that adjusts speed via changes in position, step length, and propulsion. Gains on each input dictate the impact of the corresponding parameter on belt speed. The study objective was to determine the effect of modifying the position gain on self-selected walking speed, measures of propulsion, and step length. Twenty-two participants walked at their self-selected speed with four ATM controllers, each with a unique position gain. Walking speed, anterior and posterior ground reaction force peaks and impulses, net impulse, and step length were compared between conditions. Smaller position gains promoted more equivalent anterior and posterior impulses, resulting in a net impulse closer to zero (p = 0.0043), a characteristic of healthy gait. Walking speed, anterior and posterior ground reaction force peaks and impulses, and step length did not change between conditions (all p > 0.05). These results suggest that reducing the importance of position in the ATM controller may promote more balanced anterior and posterior impulses, possibly improving the efficacy of the ATM for gait rehabilitation by emphasizing changes in gait mechanics instead of position to naturally adjust speed.

The Effects of Stroke and Stroke Gait Rehabilitation on Behavioral and Neurophysiological Outcomes:: Challenges and Opportunities for Future Research

Stroke continues to be a leading cause of adult disability, contributing to immense healthcare costs. Even after discharge from rehabilitation, post-stroke individuals continue to have persistent gait impairments, which in turn adversely affect functional mobility and quality of life. Multiple factors, including biomechanics, energy cost, psychosocial variables, as well as the physiological function of corticospinal neural pathways influence stroke gait function and training-induced gait improvements. As a step toward addressing this challenge, the objective of the current perspective paper is to outline knowledge gaps pertinent to the measurement and retraining of stroke gait dysfunction. The paper also has recommendations for future research directions to address important knowledge gaps, especially related to the measurement and rehabilitation-induced modulation of biomechanical and neural processes underlying stroke gait dysfunction. We posit that there is a need for leveraging emerging technologies to develop innovative, comprehensive, methods to measure gait patterns quantitatively, to provide clinicians with objective measure of gait quality that can supplement conventional clinical outcomes of walking function. Additionally, we posit that there is a need for more research on how the stroke lesion affects multiple parts of the nervous system, and to understand the neuroplasticity correlates of gait training and gait recovery. Multi-modal clinical research studies that can combine clinical, biomechanical, neural, and computational modeling data provide promise for gaining new information about stroke gait dysfunction as well as the multitude of factors affecting recovery and treatment response in people with post-stroke hemiparesis.

Feasibility of challenging treadmill speed-dependent gait and perturbation-induced balance training in chronic stroke patients with low ambulation ability: a randomized controlled trial

Background

Treadmill training shows advantages in the specificity, amount, and intensity of gait and balance practice for the rehabilitation of stroke patients.

Objective

To investigate the feasibility and effectiveness of challenging treadmill speed-dependent gait and perturbation-induced balance training in chronic stroke patients with low ambulation ability.

Methods

For this randomized controlled trial (Chinese Clinical Trials.gov registration number ChiCTR-IOR-16009536) with blinded testers, we recruited 33 ambulatory stroke participants with restricted community ambulation capacity and randomly assigned them into two groups: the experimental group with 2 week treadmill speed-dependent gait training combined with 2 week treadmill perturbation-induced balance training (EXP) or the control group with traditional gait and balance training (CON). Various variables were recorded during EXP training, including the rating of perceived exertion, heart rate, causes of pauses, treadmill speed, and perturbation intensity. Outcome measures were examined before training and at 2 and 4 weeks after training. They included gait velocity during five-meter walk test at comfortable and fast speed and reactive balance ability in the compensatory stepping test as primary outcome measures, as well as dynamic balance ability (timed up-and-go test and 5 times sit-to-stand test) and balance confidence as secondary outcome measures.

Results

All participants completed the study. The treadmill speed and perturbation intensity significantly increased across training sessions in the EXP group, and no adverse effects occurred. The normal and fast gait velocities showed significant time and group interaction effects. They significantly increased after 2 and 4 weeks of training in the EXP group (p < 0.05) but not in the CON group (p > 0.05). Likewise, dynamic balance ability measured using the timed up-and-go test at a fast speed significantly improved after 2 and 4 weeks of training in the EXP group (p < 0.05) but not in the CON group (p > 0.05), although without a significant time and group interaction effect. Surprisingly, the reactive balance ability did not show improvement after treatment in the EXP group (p > 0.05).

Conclusion

Challenging treadmill speed-dependent gait and treadmill perturbation-induced balance training is feasible and effective to improve ambulation function in chronic stroke patients with low ambulation ability.

Effect of power training on rate of torque development and spatiotemporal gait parameters post stroke

BACKGROUND

Maximizing independence and function post-stroke are two common therapy goals. Rate of torque development in lower-extremity muscles was recently reported to be associated with walking speed; however, trainability and subsequent effect on gait is unknown. This study aimed to determine effect of power training on paretic and non-paretic limb torque parameters, spatiotemporal gait parameters, and walking speed in chronic stroke survivors.

METHODS

Individuals with chronic stroke (n = 22; 7 females; 62.7 ± 8.8 yrs) completed 24 progressive power-training sessions over 8 weeks with pre and post assessments. Knee extensor strength was assessed via dynamometry with torque parameters measured from maximal voluntary isometric contractions. Gait speed and spatiotemporal gait parameters were assessed via an instrumented gait mat, and a 6-min walk test was performed.

FINDINGS

Rate of torque development at 200 ms and peak torque improved 58.6% and 14.1%, respectively, in the quadricep of the paretic limb (p < 0.05); conversely the non-paretic limb was unchanged. On average, self-selected walking speed, fastest-comfortable walking speed, and 6-min walk test improved 21.7%, 21.1%, and 19.5%, respectively (all p < 0.05). Change in torque development at 100 ms in the quadricep of the non-paretic limb was positively associated with improvements in self-selected and fastest-comfortable walking speeds (both r = 0.70, p < 0.05) and 6-min walk (r = 0.78, p < 0.001).

INTERPRETATIONS

These findings suggest power training may be an effective intervention for improving torque development in the quadricep of the paretic limb in individuals with chronic stroke. Further research to explore utility and mechanistic aspects of force development for gait function in chronic stroke survivors is warranted.

Robotic versus Conventional Overground Gait Training in Subacute Stroke Survivors: A Multicenter Controlled Clinical Trial

BACKGROUND

Although stroke survivors can benefit from robotic gait rehabilitation, stationary robot-assisted gait training needs further investigation. In this paper, we investigated the efficacy of this approach (with an exoskeleton or an end-effector robot) in comparison to the conventional overground gait training in subacute stroke survivors.

METHODS

In a multicenter controlled clinical trial, 89 subacute stroke survivors conducted twenty sessions of robot-assisted gait training (Robotic Group) or overground gait training (Control Group) in addition to the standard daily therapy. The robotic training was performed with an exoskeleton (RobotEXO-group) or an end-effector (RobotEND-group). Clinical outcomes were assessed before (T0) and after (T1) the treatment. The walking speed during the 10-Meter Walk Test (10 MWT) was the primary outcome of this study, and secondary outcomes were the 6-Minute Walk Test (6 MWT), Timed Up and Go test (TUG), and the modified Barthel Index (mBI).

RESULTS

The main characteristics assessed in the Robotic and Control groups did not differ at baseline. A significant benefit was detected from the 10 MWT in the Robotic Group at the end of the study period (primary endpoint). A benefit was also observed from the following parameters: 6 MWT, TUG, and mBI. Moreover, patients belonging to the Robot Group outperformed the Control Group in gait speed, endurance, balance, and ADL. The RobotEND-group improved their walking speed more than the RobotEXO-group.

CONCLUSION

The stationary robot-assisted training improved walking ability better than the conventional training in subacute stroke survivors. These results suggest that people with subacute stroke may benefit from Robot-Assisted training in potentiating gait speed and endurance. Our results also support that end-effector robots would be superior to exoskeleton robots for improving gait speed enhancement.

Spatiotemporal strategies adopted to walk at fast speed in high- and low-functioning individuals post-stroke: a cross-sectional study

BACKGROUND

Walking at fast speed is a gait training strategy post-stroke. It is unknown how faster-than-preferred pace impacts spatiotemporal gait characteristics in survivors with different functional abilities.

OBJECTIVE

To test the hypothesis that compared to high-functioning individuals, low-functioning individuals will be limited in modifying spatiotemporal gait parameters for walking at faster-than-preferred speed, and these limitations are associated with fear of falling.

METHODS

Forty-two adults, 17.6 ± 14.6 months post-stroke, traversed an instrumented walkway at preferred and fast speeds. Participants were categorized to a low-functioning group (LFG) (n = 20; <0.45 m/s) and high-functioning group (HFG) (n = 22; ≥0.45 m/s). Cadence, step length, stance time and spatiotemporal asymmetry measures were calculated. The Modified Falls-efficacy Scale examined fear of falling. Multivariate and correlational analysis tested hypotheses.

RESULTS

Increased speed from preferred to fast pace was significantly greater for HFG (0.27 ± 0.03 m/s) than LFG (0.10 ± 0.02 m/s) (p ≤ 0.001). Cadence gain from preferred to fast pace did not differ between groups. However, HFG exhibited greater change in paretic (∆6.1 ± 1.37 cm; p < .001) and non-paretic step lengths (∆4.5 ± 1.37 cm; p = .003) than LFG. Spatiotemporal asymmetry did not change for either group. Fear of falling had moderately positive correlation with ∆paretic step length (r = 0.43; p = .004) and ∆non-paretic step length (r = 0.32; p = .035).

CONCLUSIONS

While both low- and high-functioning individuals used a step-lengthening strategy to walk at faster-than-preferred speeds, the gain in step lengths was limited in low-functioning individuals and was partially explained by falls-efficacy.

Using Sensor Technology to Measure Gait Capacity and Gait Performance in Rehabilitation Inpatients with Neurological Disorders

The aim of this study was to objectively assess and compare gait capacity and gait performance in rehabilitation inpatients with stroke or incomplete spinal cord injury (iSCI) using inertial measurement units (IMUs). We investigated how gait capacity (what someone can do) is related to gait performance (what someone does). Twenty-two inpatients (11 strokes, 11 iSCI) wore ankle positioned IMUs during the daytime to assess gait. Participants completed two circuits to assess gait capacity. These were videotaped to certify the validity of the IMU algorithm. Regression analyses were used to investigate if gait capacity was associated with gait performance (i.e., walking activity and spontaneous gait characteristics beyond therapy time). The ankle positioned IMUs validly assessed the number of steps, walking time, gait speed, and stride length (r ≥ 0.81). The walking activity was strongly (r ≥ 0.76) related to capacity-based gait speed. Maximum spontaneous gait speed and stride length were similar to gait capacity. However, the average spontaneous gait speed was half the capacity-based gait speed. Gait capacity can validly be assessed using IMUs and is strongly related to gait performance in rehabilitation inpatients with neurological disorders. Measuring gait performance with IMUs provides valuable additional information about walking activity and spontaneous gait characteristics to inform about functional recovery.

Changes in corticospinal and spinal reflex excitability through functional electrical stimulation with and without observation and imagination of walking

Functional electrical stimulation (FES), a method for inducing muscle contraction, has been successfully used in gait rehabilitation for patients with deficits after neurological disorders and several clinical studies have found that it can improve gait function after stroke and spinal cord injury. However, FES gait training is not suitable for patients with walking difficulty, such as those with severe motor paralysis of the lower limbs. We have previously shown that action observation combined with motor imagery (AO + MI) of walking induces walking-related cortical activity. Therefore, we combined FES, which alternately generates dorsiflexion and plantar flexion, with AO + MI as an alternative to gait training. The present study investigates the transient effects of 20-min of FES simultaneously with and without AO + MI of walking on corticospinal and spinal reflex excitability in able-bodied participants. We measured motor evoked potentials and Hoffmann-reflexes to assess corticospinal and spinal reflex excitability at rest before and after the 20-min FES with and without the AO + MI. Our results show that FES without AO + MI did not change excitability (p &gt; 0.05), while FES with AO + MI facilitated corticospinal excitability (p &lt; 0.05). This facilitation likely occurred due to the synchronization of sensory inputs from FES and cortical activity during AO + MI. Facilitation was observed only in the dorsiflexor but not the plantar flexor muscle (p &lt; 0.05), suggesting muscle specificity of the facilitation. These results demonstrate the effectiveness of combining FES with AO + MI and pave the way for novel neurorehabilitation strategies for patients with neurological gait deficits.

Evidence for shared neural information between muscle synergies and corticospinal efficacy

Stroke survivors often exhibit gait dysfunction which compromises self-efficacy and quality of life. Muscle Synergy Analysis (MSA), derived from electromyography (EMG), has been argued as a method to quantify the complexity of descending motor commands and serve as a direct correlate of neural function. However, controversy remains regarding this interpretation, specifically attribution of MSA as a neuromarker. Here we sought to determine the relationship between MSA and accepted neurophysiological parameters of motor efficacy in healthy controls, high (HFH), and low (LFH) functioning stroke survivors. Surface EMG was collected from twenty-four participants while walking at their self-selected speed. Concurrently, transcranial magnetic stimulation (TMS) was administered, during walking, to elicit motor evoked potentials (MEPs) in the plantarflexor muscles during the pre-swing phase of gait. MSA was able to differentiate control and LFH individuals. Conversely, motor neurophysiological parameters, including soleus MEP area, revealed that MEP latency differentiated control and HFH individuals. Significant correlations were revealed between MSA and motor neurophysiological parameters adding evidence to our understanding of MSA as a correlate of neural function and highlighting the utility of combining MSA with other relevant outcomes to aid interpretation of this analysis technique.

Adaptive treadmill control can be manipulated to increase propulsive impulse while maintaining walking speed

Adaptive treadmills (ATM) designed to promote increased propulsion may be an effective tool for gait training since propulsion is often impaired post-stroke. Our lab developed a novel ATM controller that adjusts belt speed via real-time changes in step length, propulsive impulse, and position. This study modified the relative importance of propulsion to step length in the controller to determine the effect of increased propulsive feedback gain on measures of propulsion and walking speed. Twenty-two participants completed five trials at their self-selected speed, each with a unique ATM controller. Walking speed, peak AGRF and PGRF, and AGRF, PGRF, and net impulse were compared between the modifications using one-way repeated measures ANOVAs at a significance level of 0.05. Participants chose similar walking speeds across all conditions (all p > 0.2730). There were no significant differences in peak AGRF (p = 0.1956) or PGRF (p = 0.5159) between conditions. AGRF impulse significantly increased as the gain on the propulsive impulse term was increased relative to the gain on step length (p < 0.0001) while PGRF and net impulse were similar across all conditions (p = 0.5487). Increasing the propulsive impulse gain essentially alters the treadmill environment by providing a controlled amount of resistance to increases in propulsive forces. Our findings demonstrate that the ATM can be modified to promote increased propulsive impulse while maintaining a consistent walking speed. Since increasing propulsion is a common goal of post-stroke gait training, these ATM modifications may improve the efficacy of the ATM for gait rehabilitation.

Dance-based exergaming on postural stability and kinematics in people with chronic stroke - A preliminary study

INTRODUCTION

The study evaluated the feasibility, and compliance of a dance-based exergaming (DBExG) on postural stability (PS) and lower extremity (LE) kinematics, along with post-intervention changes in gait function and falls self-efficacy in people with chronic stroke (PwCS).

METHODS

Fifteen PwCS underwent DBExG for six weeks using Kinect "Just Dance 3." Pre- to post- changes were recorded during DBExG assessment on a fast-paced song (130 bpm) using an 8-camera motion capture system to assess PS (center of mass [CoM] excursions [EXs] in the anterior-posterior [AP] and mediolateral [ML] directions) and LE kinematics (hip, knee, and ankle joint angle EXs). Gait function was also assessed with gait parameters, such as gait speed, cadence, and gait symmetry on an electronic walkway. Falls self-efficacy was recorded with Falls Efficacy Scale (FES).

RESULTS

The AP and ML CoM EXs and paretic joint angle EXs significantly increased pre- to post- DBExG assessment (p < .05). Gait parameters, and falls self-efficacy measures significantly changed pre- to post- DBExG (p < .05).

CONCLUSIONS

Results exhibited the feasibility of the proposed DBExG for positively impacting postural stability, and kinematics, along with increasing gait function and falls self-efficacy among PwCS.

A Brake-Based Overground Gait Rehabilitation Device for Altering Propulsion Impulse Symmetry

This paper introduces a new device for gait rehabilitation, the gait propulsion trainer (GPT). It consists of two main components (a stationary device and a wearable system) that work together to apply periodic stance-phase resistance as the user walks overground. The stationary device provides the resistance forces via a cable that tethers the user’s pelvis to a magnetic-particle brake. The wearable system detects gait events via foot switches to control the timing of the resistance forces. A hardware verification test confirmed that the GPT functions as intended. We conducted a pilot study in which one healthy adult and one stroke survivor walked with the GPT with increasing resistance levels. As hypothesized, the periodic stance-phase resistance caused the healthy participant to walk asymmetrically, with greatly reduced propulsion impulse symmetry; as GPT resistance increased, the walking speed also decreased, and the propulsion impulse appeared to increase for both legs. In contrast, the stroke participant responded to GPT resistance by walking faster and more symmetrically in terms of both propulsion impulse and step length. Thus, this paper shows promising results of short-term training with the GPT, and more studies will follow to explore its long-term effects on hemiparetic gait.

Effect of different walking speeds on joint and muscle force estimation using AnyBody and OpenSim

BACKGROUND

To be able to use muscluloskeletal models in clinical settings, it is important to understand the effect of walking speed on joint and muscle force estimations in different generic musculoskeletal models.

RESEARCH QUESTION

The aim of the current study is to compare estimated joint and muscle forces as a function of walking speed between two standard approaches offered in two different modelling environments (AnyBody and OpenSim).

METHODS

Experimental data of 10 healthy participants were recorded at three different walking speeds (self-selected, 25 % slower, 25 % faster) using a ten-camera motion capture system together with four force plates embedded into a ten-meter walkway. Joint compression forces and muscle forces were calculated with a generic model in AnyBody and OpenSim. Trend analyses, mean absolute error (MAE) and correlation coefficients were used to compare joint compression forces and muscle forces between the two approaches. A one-way and two-way ANOVA with repeated measures were used to compare MAE and trend analysis changes, respectively (α = 0.05, Bonferroni corrected post-hoc tests).

RESULTS

Trend analyses showed the same speed effect for AnyBody and OpenSim. MAEs increased significantly from slow to fast walking for knee joint compression forces, biceps femoris long head, gluteus maximus, gluteus medius and vastus intermedius. Lower correlation coefficients during slower walking were found for quadriceps muscles, gluteus maximus and biceps femoris compared to normal and faster walking.

SIGNIFICANCE

Lower correlation coefficients during slower walking are assumed to be due to a higher amount of solutions solving the muscle recruitment in musculoskeletal models. This indicates that decreasing walking speed is more prone to speed dependent differences regarding variability, while the absolute error increased with increasing walking speed. To conclude, different modelling environments can react differently to changes in walking speed, but overall results are promising regarding the generalization across different generic musculoskeletal models.

Neglected physical human-robot interaction may explain variable outcomes in gait neurorehabilitation research

[Figure: see text].

Understanding the effects of quantitatively prescribing passive-dynamic ankle-foot orthosis bending stiffness for individuals after stroke

BACKGROUND

Passive-dynamic ankle-foot orthosis (PD-AFO) bending stiffness, which assists plantar flexor function, can be prescribed to improve poststroke gait. However, outcomes with PD-AFOs are variable likely because of improper personalization. We implemented a prescription model that objectively personalizes PD-AFO bending stiffness based on each individual's level of plantar flexor weakness (quantitatively prescribed PD-AFO).

OBJECTIVES

To evaluate whether a quantitatively prescribed PD-AFO improves peak paretic plantar flexion moment compared with the original AFO for individuals after stroke and to examine the immediate effects of wearing a quantitatively prescribed PD-AFO.

STUDY DESIGN

This is a repeated-measures study.

METHODS

PD-AFO bending stiffness was personalized for 10 individuals after stroke through the previously developed prescription model. Participants underwent an instrumented gait analysis while wearing their original AFO and the quantitatively prescribed PD-AFO.

RESULTS

Participants' peak paretic plantar flexion moment significantly increased while wearing the quantitatively prescribed PD-AFO compared with the original AFO. In addition, participants showed different levels of improvements in a series of other key biomechanical and walking performance parameters with PD-AFO use. Some participants showed improvements in all parameters, whereas others showed moderate to no improvements.

CONCLUSIONS

Quantitatively prescribed PD-AFO bending stiffness resulted in inconsistent improvements in biomechanical and walking performance parameters, which warrants further investigation. Future work should investigate whether more consistent benefits are seen with faster walking speeds and longer-term PD-AFO use. In addition, future work should conduct larger-scale studies that aim to understand and optimize orthosis-patient matching for all AFO designs/characteristics.

Immediate effects of stance and swing phase training on gait in patients with stroke

To compare the effects of gait trainings targeting the stance (stance training) and the swing phases (swing training) among the subjects with stroke, and quantify the characteristics in the subjects who benefitted from either the stance training or the swing training. Sixteen subjects with stroke performed the stance training, which focused on the center of pressure to move from the heel to the forefoot, and the swing training, which focused on the improvement of hip flexion in the swing phase. To investigate the immediate effects of the stance training and the swing training, the instrumented gait analysis was performed before and after training. To quantify the characteristics, subjects were divided into two groups based on the gait speed change. These two groups were compared using clinical examinations. After the stance training, the center of pressure displacement of the paretic limb was increased compared with the swing training. Subjects who benefitted from the stance training had slower Timed Up and Go and weaker paretic hip muscle strength than those who benefitted from the swing training. Stance training may be more effective in subjects with slower Timed Up and Go outcomes and weaker hip muscles.

Force-Control vs. Strength Training: The Effect on Gait Variability in Stroke Survivors

Purpose: Increased gait variability in stroke survivors indicates poor dynamic balance and poses a heightened risk of falling. Two primary motor impairments linked with impaired gait are declines in movement precision and strength. The purpose of the study is to determine whether force-control training or strength training is more effective in reducing gait variability in chronic stroke survivors.

Methods: Twenty-two chronic stroke survivors were randomized to force-control training or strength training. Participants completed four training sessions over 2 weeks with increasing intensity. The force-control group practiced increasing and decreasing ankle forces while tracking a sinusoid. The strength group practiced fast ankle motor contractions at a percentage of their maximal force. Both forms of training involved unilateral, isometric contraction of the paretic, and non-paretic ankles in plantarflexion and dorsiflexion. Before and after the training, we assessed gait variability as stride length and stride time variability, and gait speed. To determine the task-specific effects of training, we measured strength, accuracy, and steadiness of ankle movements.

Results: Stride length variability and stride time variability reduced significantly after force-control training, but not after strength training. Both groups showed modest improvements in gait speed. We found task-specific effects with strength training improving plantarflexion and dorsiflexion strength and force control training improving motor accuracy and steadiness.

Conclusion: Force-control training is superior to strength training in reducing gait variability in chronic stroke survivors. Improving ankle force control may be a promising approach to rehabilitate gait variability and improve safe mobility post-stroke.

Minimal clinically Important difference of Gait Assessment and Intervention Tool (G.A.I.T.) in patients with sub-acute stroke

BACKGROUND

The Gait Assessment and Intervention Tool (G.A.I.T.) is a well-accepted tool to determine gait characteristics in neurological patients.

AIM

The aim of this study was to determine the minimal clinically importance difference (MCID) of the G.A.I.T in sub-acute stroke patients.

DESIGN

Prospective study.

SETTING

An in- and out-patient rehabilitation clinic in a university hospital in Thailand.

POPULATION

Patients with sub-acute stroke who had an ongoing rehabilitation between October 2017 to March 2019.

METHODS

We used an anchor-based method to determine change in G.A.I.T. score needed to achieve MCID. Participants were dichotomized to 'no change group' or 'positive change group' based on different anchors of objective and subjective perceived changes in gait function after 4 weeks of rehabilitation. The groups were determined based on whether 1) participants achieved an increase in comfortable gait speed (CGS) of ≥ 0.06 m/s, 2) averaged Global Rating Of Change (GROC) score was ≥ +3 evaluated by two physiatrists 3) GROC score of was ≥ +3 rated by the participants. The best cut-off point was the score which most successfully separated these two groups within the ROC curve.

RESULTS

Thirty-one participants with sub-acute stroke (18 males, 13 female) completed both assessments. Their average age was 60.3 years (SD 11.4). The best cut-off point were a 2.5- and 4-point improvements in G.A.I.T. score based on changes in CGS (AUC 0.76, 95%CI 0.58-0.95) and clinicians' perceived changes (AUC 0.88, 95% CI 0.76-1.00). Additionally, the best cut-off point was 1.5 (AUC 0.71 95% CI 0.31-1.00) when determined by participants' perception. All anchors yielded adequate discriminative ability. The positive likelihood ratio (LR) was in the range of 2.7-5.5 and the negative LR range was 0.1-0.3.

CONCLUSIONS

A change in G.A.I.T. score should exceed 1.5, 2.5 and 4 to be considered MCID based on participants' GROC, CGS and Clinicians' GROC anchors. This information will be useful for the determination of changes after rehabilitation and for tracking sub-acute stroke patients' progress.

Correlation between the strength of muscle actions of the paretic lower-limb and gait speed after Stroke: Results of a meta-analysis of six studies

BACKROUND AND OBJECTIVE: Lower limb strength, particularly of the more paretic side, is known to correlate with comfortable gait speed. This meta-analysis sought to determine the relative value of 6 muscle group strengths as explanators of comfortable gait speed. METHODS: Relevant literature was sought using PubMed, CINAHL Scopus, and a hand search. Information on samples, measurements, and correlations were extracted. Correlational data were subjected to meta-analysis. RESULTS: Results from 6 studies were consolidated. The summary correlations between paretic lower limb strength and comfortable gait speed ranged from 0.45 to 0.61. Data were highly heterogeneous but did not show publication bias. CONCLUSIONS: The correlation between the lower limb strength and comfortable gait speed strength is moderate. However, it does not provide an adequate explanation to guide clinical practice.

Combined user-driven treadmill control and functional electrical stimulation increases walking speeds poststroke

The variety of poststroke impairments and compensatory mechanisms necessitate adaptive and subject-specific approaches to locomotor rehabilitation. To implement subject-specific, adaptive training to treadmill-based gait training, we developed a user-driven treadmill (UDTM) control algorithm that adjusts the user's speed in real-time. This study examines the response of individuals poststroke to the combination of UDTM control and electrical stimulation of the paretic ankle musculature to augment forward propulsion during walking. Sixteen individuals poststroke performed a randomized series of walking tasks on an instrumented split-belt treadmill at their self-selected speeds 1) with fixed speed treadmill (FSTM) control only, 2) FSTM control and paretic limb functional electrical stimulation (FES), 3) UDTM control only, and 4) UDTM control and FES. With UDTM control and FES, participants selected speeds that were 0.13 m/s faster than their speeds with fixed speed control only. This instantaneous increase is comparable to the gains in SS speed seen after 12 weeks of training with FES and fast walking with fixed speed treadmill control by Kesar and colleagues (Δ = 0.18 m/s). However, we saw no significant differences in the corresponding push-off forces or trailing limb position. Since individuals can use a variety of strategies to change their walking speeds, it is likely that the differences among individual responses obscured trends in the group average changes in mechanics. Ultimately, the combination of UDTM control and functional electrical stimulation (FES) allows individuals to increase speeds after a short exposure and may be a beneficial addition to poststroke gait training programs.

Development of Gait Ability Assessment for hemiplegics (GAA) and verification of inter-rater reliability and validity

Tomida K, Tanino G, Sonoda S, Hirano S, Itoh N, Saitoh E, Kagaya H, Suzuki A, Kawakami K, Miyajima T, Takai M. Development of Gait Ability Assessment for hemiplegics (GAA) and verification of inter-rater reliability and validity. Jpn J Compr Rehabil Sci 2021; 12: 19-26.

Objective

To develop the Gait Ability Assessment for hemiplegics (GAA), and to verify its validity and inter-rater reliability.

Methods

We developed the GAA, a new method for the assessment of gait ability. Next, we examined the inter-rater reliability of GAA by assessing gait ability of post-stroke patients by two physical therapists. Then, we verified the validity of GAA by comparing with the existing assessments methods comprising Functional Ambulation Categories (FAC), Functional Independence Measure (FIM)-walk, maximum walking speed, motor subscore of the FIM (FIM-M), and total score of affected-side motor function of the Stroke Impairment Assessment Set (SIAS-L/E).

Results

Regarding the inter-rater reliability of GAA, κ coefficient was 0.76 and weighted κ coefficient was 0.96. The correlation coefficients between GAA scores and existing assessment methods were: 0.95 for FAC scores, 0.95 for FIM-walk scores, 0.82 for maximum walking speed, 0.89 for FIM-M, and 0.61 for SIAS-L/E, all of which showed a significant correlation (p<0.01).

Conclusion

GAA has high inter-rater reliability as well as high validity as a gait ability assessment method, suggesting that it can be applied to research and clinical settings.

Ipsilateral Motor Pathways and Transcallosal Inhibition During Lower Limb Movement After Stroke

BACKGROUND

Stroke rehabilitation may be improved with a better understanding of the contribution of ipsilateral motor pathways to the paretic limb and alterations in transcallosal inhibition. Few studies have evaluated these factors during dynamic, bilateral lower limb movements, and it is unclear whether they relate to functional outcomes.

OBJECTIVE

Determine if lower limb ipsilateral excitability and transcallosal inhibition after stroke depend on target limb, task, or number of limbs involved, and whether these factors are related to clinical measures.

METHODS

In 29 individuals with stroke, ipsilateral and contralateral responses to transcranial magnetic stimulation were measured in the paretic and nonparetic tibialis anterior during dynamic (unilateral or bilateral ankle dorsiflexion/plantarflexion) and isometric (unilateral dorsiflexion) conditions. Relative ipsilateral excitability and transcallosal inhibition were assessed. Fugl-Meyer, ankle movement accuracy, and walking characteristics were assessed.

RESULTS

Relative ipsilateral excitability was greater during dynamic than isometric conditions in the paretic limb (P ≤ .02) and greater in the paretic than the nonparetic limb during dynamic conditions (P ≤ .004). Transcallosal inhibition was greater in the ipsilesional than contralesional hemisphere (P = .002) and during dynamic than isometric conditions (P = .03). Greater ipsilesional transcallosal inhibition was correlated with better ankle movement accuracy (R² = 0.18, P = .04). Greater contralateral excitability to the nonparetic limb was correlated with improved walking symmetry (R² = 0.19, P = .03).

CONCLUSIONS

Ipsilateral pathways have increased excitability to the paretic limb, particularly during dynamic tasks. Transcallosal inhibition is greater in the ipsilesional than contralesional hemisphere and during dynamic than isometric tasks. Ipsilateral pathways and transcallosal inhibition may influence walking asymmetry and ankle movement accuracy.

Does Falls Efficacy Influence the Relationship Between Forward and Backward Walking Speed After Stroke?

OBJECTIVE

Forward walking speed (FWS) is known to be an important predictor of mobility, falls, and falls-related efficacy poststroke. However, backward walking speed (BWS) is emerging as an assessment tool to reveal mobility deficits in people poststroke that may not be apparent with FWS alone. Since backward walking is more challenging than forward walking, falls efficacy may play a role in the relationship between one's preferred FWS and BWS. We tested the hypothesis that people with lower falls efficacy would have a stronger positive relationship between FWS and BWS than those with higher falls efficacy.

METHODS

Forty-five individuals (12.9 ± 5.6 months poststroke) participated in this observational study. We assessed FWS with the 10-meter walk test and BWS with the 3-meter backward walk test. The modified Falls-Efficacy Scale (mFES) quantified falls efficacy. A moderated regression analysis examined the hypothesis.

RESULTS

FWS was positively associated with BWS (R2 = 0.26). The addition of the interaction term FWS × mFES explained 7.6% additional variance in BWS. As hypothesized, analysis of the interaction revealed that people with lower falls efficacy (mFES ≤ 6.6) had a significantly positive relationship between their preferred FWS and BWS, whereas people with higher falls efficacy (mFES > 6.6) had no relationship between their walking speed in the 2 directions.

CONCLUSIONS

FWS is positively related to BWS poststroke, but this relationship is influenced by one's perceived falls efficacy. Our results suggest that BWS can be predicted from FWS in people with lower falls efficacy, but as falls efficacy increases, BWS becomes a separate and unassociated construct from FWS.

IMPACT

This study provides unique evidence that the degree of falls efficacy significantly influences the relationship between FWS and BWS poststroke. Physical therapists should examine both FWS and BWS in people with higher falls efficacy, but further investigation is warranted for those with lower falls efficacy.

Lessons Learned: The Difficulties of Incorporating Intensity Principles Into Inpatient Stroke Rehabilitation

Objective

The objective of this study was to determine the feasibility of a rehabilitation approach focusing on cardiovascular, strength, and gait training intensity in the inpatient rehabilitation setting after a new onset of stroke. We additionally aimed to determine the efficacy of this intensity-based program on rehabilitation outcomes compared with usual care.

Design

Participants were pseudo-randomized to an intensity-based program focusing on gait, cardiovascular, and strength training or to usual care. Outcomes included FIM, 10-meter walk, 2-minute walk, timed Up and Go test, 5-time sit-to-stand test, and Tinetti balance assessment.

Intervention

The intervention consisted of 6 20-minute sessions per week dedicated to intensity of activity: 2 each for walking, cardiovascular training, and strength training.

Participants

Patients (N=49) with new onset stroke admitted to inpatient rehabilitation over the course of 1 year.

Setting

Four inpatient rehabilitation facilities with comprehensive neurologic rehabilitation teams.

Results

Thirty-five individuals (16 intervention, 19 controls) completed all testing. Subject compliance to the intensity intervention demonstrated completion of approximately half the prescribed sessions. All outcomes improved significantly from admission to discharge, and a significant interaction between treatment group and time was observed for the 2-minute walk and the Tinetti balance assessment. The 2-minute walk, Tinetti balance assessment, 10-meter walk, and FIM demonstrated between-group effect sizes greater than 0.60 in favor of the intervention group.

Conclusions

The intensity-based protocol was safe, and several measures demonstrated efficacy when compared with usual care. Results may have been limited by poor program compliance, showing a need to identify and ameliorate obstacles to integration of comprehensive intensity-based programs addressing endurance, strength, and gait training. Applying physiological principles of exercise to acute stroke rehabilitation demonstrates great promise for improving independent physical function.

A simple, clinically applicable motor learning protocol to increase push-off during gait: A proof-of-concept

OBJECTIVE

Task-specific training is often used in functional rehabilitation for its potential to improve performance at locomotor tasks in neurological populations. As push-off impairment are often seen with these patients, this functional approach shows potential to retrain gait overground to normalize the gait pattern and retrain the ability to improve gait speed. The main objective of this project was to validate, in healthy participants, a simple, low-cost push-off retraining protocol based on task-specific training that could be implemented during overground walking in the clinic.

METHODS

30 healthy participants walked in an 80-meter long corridor before, during, and after the application of an elastic resistance to the right ankle. Elastic tubing attached to the front of a modified ankle-foot orthosis delivered the resistance during push-off. Relative ankle joint angular displacements were recorded bilaterally and continuously during each walking condition.

RESULTS

On the resisted side, participants presented aftereffects (increased peak plantarflexion angle from 13.4±4.2° to 20.0±6.4°, p<0.0001 and increased peak plantarflexion angular velocity from 145.8±22.7°/s to 174.4±37.4°/s, p<0.0001). On the non-resisted side, aftereffects were much smaller than on the resisted side suggesting that the motor learning process was mainly specific to the trained leg.

CONCLUSION

This study shows the feasibility of modifying push-off kinematics using an elastic resistance applied at the ankle while walking overground. This approach represents an interesting venue for future gait rehabilitation.

Relationship between Muscular Activity and Postural Control Changes after Proprioceptive Focal Stimulation (Equistasi®) in Middle-Moderate Parkinson's Disease Patients: An Explorative Study

The aim of this study was to investigate the effects of Equistasi^®, a wearable device, on the relationship between muscular activity and postural control changes in a sample of 25 Parkinson’s disease (PD) subjects. Gait analysis was carried out through a six-cameras stereophotogrammetric system synchronized with two force plates, an eight-channel surface electromyographic system, recording the activity of four muscles bilaterally: Rectus femoris, tibialis anterior (TA), biceps femoris, and gastrocnemius lateralis (GL). The peak of the envelope (PoE) and its occurrence within the gait cycle (position of the peak of the envelope, PPoE) were calculated. Frequency-domain posturographic parameters were extracted while standing still on a force plate in eyes open and closed conditions for 60 s. After the treatment with Equistasi^®, the mid-low (0.5–0.75) Hz and mid-high (0.75–1 Hz) components associated with the vestibular and somatosensory systems, PoE and PPoE, displayed a shift toward the values registered on the controls. Furthermore, a correlation was found between changes in proprioception (power spectrum frequencies during the Romberg Test) and the activity of GL, BF (PoE), and TA (PPoE). Results of this study could provide a quantitative estimation of the effects of a neurorehabilitation device on the peripheral and central nervous system in PD.

Augmented-reality guided treadmill training as a modality to improve functional mobility post-stroke: A proof-of-concept case series

Objective: To provide a proof-of-concept for a novel stroke-gait-specific augmented reality (AR)-guided treadmill intervention by evaluating its effect on temporospatial and functional outcomes of mobility.Methods: Two females with hemiplegia post stroke were recruited for participation in a 4-week intervention, and a single healthy control was recruited for baseline comparisons. The stroke-intervention (SI) participant (aged 54-years), completed 12 sessions of AR-guided treadmill intervention. The stroke-control (SC) participant (aged 59-years) completed 12 sessions of conventional treadmill intervention. Temporospatial and functional mobility were assessed pre-intervention, post-intervention, and at 1-month follow-up. Physical ACtivity Enjoyment Scale (PACES) was administered post-intervention.Results: The SI participant showed clinically meaningful improvements in functional outcomes post-intervention and at 1-month follow-up (Berg balance score (BBS): +6 and +10 points; Dynamic Gait Index (DGI): +2 at post-intervention only; walking speed: +0.19 and +0.24 m/s; 6-minute walk test (6MWT): +51.9 and +38.9) respectively. The SC showed clinically meaningful improvements in BBS (+3 and +3) and walking speed (+0.06 at post-intervention). The PACES scores showed that the SI participant had a significantly higher (23 points) enjoyment level during the intervention compared to the SC participant. The SI participant was more asymmetric compared to the SC participant at pre and post-intervention visits.Conclusions: The SI participant showed greater improvement in functional assessments compared to the SC participant post intervention. The AR-guided approach may have added benefits compared to traditional treadmill training, while providing better customization, patient enjoyment, and engagement. Further investigation with a larger sample is warranted.

Does overground robotic gait training improve non-motor outcomes in patients with chronic stroke? Findings from a pilot study

Stroke is the leading cause of disability among the elderly in the industrialized world. No more than 40% of stroke survivors walk independently, and only after receiving appropriate rehabilitation treatment; many stroke patients have also non-motor symptoms. The aim of this pilot study is to evaluate the effects of Ekso-training on non-motor outcomes, including gastrointestinal function and psychological well-being, in post stroke patients. We enrolled 30 post-stroke subjects, which were randomized into two groups in order of recruitment: 15 patients were trained with the overground exoskeleton Ekso-GT (experimental group, EG), whereas 15 patients were submitted to a standard gait training (control group, CG). Both the groups underwent the same amount of physiotherapy. At the end of the training, only in the EG we observed a significant improvement in constipation, mood, and coping strategies, with regard to social support, as well as in the perception of quality of life (as per SF-12). According to these preliminary data, overground robotic gait training can be considered a valuable tool in improving non-motor symptoms, including constipation and behavioral disorders in patients with chronic stroke.

Asymmetry and Variability Should Be Included in the Assessment of Gait Function in Poststroke Hemiplegia With Independent Ambulation During Early Rehabilitation

OBJECTIVE

To extract independent features from spatiotemporal data of poststroke gait.

DESIGN

Retrospective observational study.

SETTING

Motion analysis laboratory in the rehabilitation department of a university hospital.

PARTICIPANTS

Convenience sample from inpatients in subacute recovery stage post stroke. Of 98 patients post stroke who underwent gait assessment, 69 patients post stroke were included in the data analysis (N=69). They could walk more than 10 m without personal assist or assistive devices.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Spatiotemporal parameters during level walking and their asymmetry and variability were obtained by insole foot pressure measurement system.

RESULTS

Of independent components extracted by principal component analysis, 3 independent components explained 81.9% of total variance of spatiotemporal poststroke gait data. The first component has associations with walking speed and proportion of double support phase, and it explains 46.6% of total variance. The second component has association with temporal asymmetry, and it explains 21.1% of total variance. The third component has association with temporal variability, and it explains 14.2% of total variance. Principal component scores did not show significant differences between stroke types and among stroke lesions.

CONCLUSIONS

Temporal asymmetry and variability should be included in the assessment of poststroke gait during early rehabilitation. They are independent of each other and provide characteristics of poststroke gait that are independent to the walking speed. They are helpful for rehabilitation planning and developing treatment strategy in poststroke gait rehabilitation.

Feasibility and Safety of Transcranial Direct Current Stimulation in an Outpatient Rehabilitation Setting After Stroke

Transcranial direct current stimulation (tDCS) has strong potential for outpatient clinical use, but feasibility and safety of tDCS has only been evaluated in laboratory and inpatient clinical settings. The objective of this study was to assess feasibility and safety of tDCS for stroke in an outpatient clinical setting. Individuals with stroke in outpatient therapy received tDCS during physical therapy sessions. Feasibility was assessed with screening, enrollment, withdrawal, and adherence numbers, tDCS impressions, and perceived benefits and detriments of tDCS. Acute changes in fatigue and self-reported function and pre-post changes in fatigue were also assessed. Safety was assessed as adverse events and side effects. In total, 85 individuals were screened, and 10 were enrolled. Most exclusions were unrelated to clinical feasibility. In total, 3 participants withdrew, so 7 participants completed 2 sessions/week for 5–6 weeks with 100% adherence. In total, 71% reported positive impressions of tDCS. tDCS setup decreased to 5–7 min at end of study. There was one adverse event unrelated to tDCS. Mild to moderate side effects (tingling, itching, pinching, and fatigue) were experienced. In total, 86% of participants recounted benefits of tDCS. There were acute improvements in function and energy. Results support the feasibility and safety of tDCS in an outpatient clinical setting.

Validity and Reliability of the Thai Version of the Gait Assessment and Intervention Tool (G.A.I.T.)

Introduction. The Gait Assessment and Intervention Tool (G.A.I.T.) is well-accepted for determining changes in gait quality in neurological patients. This study is aimed at translating the G.A.I.T. to Thai and to examine its validity and reliability. Methods. The Thai translation and back-translation into English were done according to international guidelines. Sixty-eight patients with subacute to chronic stroke were recruited. Concurrent validity was determined by the correlation coefficient between the Thai G.A.I.T. scale and a comfortable vs. fast gait speed. The convergent validity was determined by the correlation coefficient between the Thai G.A.I.T. and the lower extremity Motricity Index, the Functional Ambulation Category (FAC), and the National Institutes of Health Stroke Scale (NIHSS). Interrater reliability was assessed using videos of 68 patients analysed by two independent raters. Each rater was randomly assigned to rescore the Thai G.A.I.T. for each patient over at least two weeks to assess intrarater reliability. Results. The concurrent validity of the Thai G.A.I.T. vs. the respective comfortable and fast gait speeds was excellent (Rs=−0.79 and Rs=−0.68, p<0.001). The respective convergent validity with the lower extremity Motricity Index, NIHSS, and FAC was Rs=−0.62, 0.57, and -0.51, respectively. The respective inter- and intrarater reliabilities were excellent (ICC=0.93, 95% CI 0.88-0.96 and 0.95, 95% CI 0.91-0.97). Conclusion. A Thai version of the G.A.I.T. was developed, and its validity and reliability for use among patients with subacute to chronic stroke were established. Further work regarding the responsiveness of the tool is needed.

Mobility Disorders in Stroke, Parkinson Disease, and Multiple Sclerosis: A Multicenter Cross-Sectional Study

OBJECTIVE

The aims of the study were to compare mobility in multiple sclerosis, Parkinson disease, and stroke, and to quantify the relationship between mobility and participation restrictions.

DESIGN

This is a multicenter cross-sectional study. Included were compliant subjects with Parkinson disease, multiple sclerosis, and stroke seen for rehabilitation, with no comorbidities interfering with mobility. Functional scales were applied to each subject to investigate gait speed (10-meter walking test), balance while maintaining body position (Berg Balance Scale), dynamic balance and mobility (Timed Up and Go and Dynamic Gait Index), and participation (Community Integration Questionnaire).

RESULTS

Two hundred ninety-nine patients (111 multiple sclerosis, 94 Parkinson disease, and 94 stroke) were enrolled. Stroke had the slowest gait speed (mean gait speed = 0.9 m/sec) compared with Parkinson disease (1.1 m/sec), and multiple sclerosis (1.2 m/sec) (P < 0.001). Multiple sclerosis was more limited than Parkinson disease and stroke in dynamic balance both in the Timed Up and Go Test (multiple sclerosis = 16.7 secs, Parkinson disease = 11.4 secs, stroke = 14.0 secs; P < 0.001) and Dynamic Gait Index (multiple sclerosis = 11.6 points, Parkinson disease = 12.9 points, stroke = 13.6 points; P = 0.03); ability to maintain balance and body position (Berg Balance Scale) was more affected in stroke and Parkinson disease than multiple sclerosis (multiple sclerosis = 42.6 points, Parkinson disease = 39.4 points, stroke = 39.7 points; P = 0.03). Balance disorders were associated with participation restrictions but not gait speed.

CONCLUSIONS

Neurological conditions have differing impacts on gait and balance, leading to different levels of participation restriction.

A Review of Robot-Assisted Lower-Limb Stroke Therapy: Unexplored Paths and Future Directions in Gait Rehabilitation

Stroke affects one out of every six people on Earth. Approximately 90% of stroke survivors have some functional disability with mobility being a major impairment, which not only affects important daily activities but also increases the likelihood of falling. Originally intended to supplement traditional post-stroke gait rehabilitation, robotic systems have gained remarkable attention in recent years as a tool to decrease the strain on physical therapists while increasing the precision and repeatability of the therapy. While some of the current methods for robot-assisted rehabilitation have had many positive and promising outcomes, there is moderate evidence of improvement in walking and motor recovery using robotic devices compared to traditional practice. In order to better understand how and where robot-assisted rehabilitation has been effective, it is imperative to identify the main schools of thought that have prevailed. This review intends to observe those perspectives through three different lenses: the goal and type of interaction, the physical implementation, and the sensorimotor pathways targeted by robotic devices. The ways that researchers approach the problem of restoring gait function are grouped together in an intuitive way. Seeing robot-assisted rehabilitation in this unique light can naturally provoke the development of new directions to potentially fill the current research gaps and eventually discover more effective ways to provide therapy. In particular, the idea of utilizing the human inter-limb coordination mechanisms is brought up as an especially promising area for rehabilitation and is extensively discussed.

Walking speed changes in response to user-driven treadmill control after stroke

The objective of this study was to determine how individuals poststroke respond to user-driven treadmill (UDTM) controlin terms ofwalking speeds, peak anterior ground reaction forces (AGRF), peak posterior ground reaction forces (PGRF), and trailing limb angles (TLA). Twenty individuals with chronic stroke walked overground during a 10-meter walk test to determine their self-selected (SS) speeds before walking on a treadmill in its fixed-speed (FSTM) and UDTM control modes at their SS and fastest comfortable (Fast) speeds. Paired t-tests were used to compare the walking speeds, peak AGRF, peak PGRF, and TLA among test conditions (α = 0.05). Participants selected similar SS (p > 0.05) and faster Fast walking speeds (p < 0.05) with the UDTM control compared to the FSTM control. There were no changes in their peak AGRF or PGRF for either limb or speed between UDTM and FSTM conditions (p > 0.05). Individuals used greater paretic TLA at SS speeds with UDTM control (p < 0.05). There was no difference in the AGRF required at Fast speeds with FSTM and UDTM control even though participants selected faster speeds with UDTM control. In work with young, healthy adults, we found that the treadmill control condition did not affect the amount of forward propulsion needed. Therefore, it is likely that when walking with UDTM control, individuals poststroke adjust their posture to make better use of their forward propulsion. This means they can reach faster walking speeds without increasing their push-off forces. Future work should assess how to most effectively prescribe UDTM control for gait training programs.

The impact of motor task and environmental constraints on gait patterns during treadmill walking in a fully immersive virtual environment

BACKGROUND

Virtual environments (VE) are increasingly used in rehabilitation settings for gait training, and positive effects are reported. However, little is known about how walking under environmental constraints and solving motor tasks in fully immersive VEs impact gait patterns.

RESEARCH QUESTION

How are gait patterns in healthy adults impacted by walking under environmental constraints and solving motor tasks on a treadmill, in a fully immersive VE?

METHODS

29 healthy adults (age: 28.9±4.8 yrs) were included. Basic gait parameters (step length, cadence, walk ratio) and gait variability in the anteroposterior, mediolateral and vertical directions were measured using an inertial sensor attached to the lower back. A familiarisation treadmill walk >2 min was performed, followed by 200 m familiarisation walk in the VE with no task or environmental constraints The participants were then exposed to height, two grabbing tasks, a balancing task and narrow-path walking. Gait patterns were captured for 15-25 seconds during each of the conditions. The Simulator Sickness Questionnaire was completed before and after the session.

RESULTS

Gait regularity decreased when solving all the motor tasks, and under all the environmental constraints, except when being familiarised to height exposure, where regularity returned to pre-exposure levels. Step length and walk ratio decreased, and cadence increased during height exposure and while performing the grabbing tasks and the balancing task. The different tasks and environments appeared to have specific impact on gait patterns. There was no increase in simulator sickness symptoms.

SIGNIFICANCE

Gait patterns were impacted by solving motor tasks, and by environmental constraints, in healthy young adults, suggesting increased need for balance control. We suggest that VE-training on a treadmill holds potential for improving gait and balance control.

Biomechanical correlates for recovering walking speed following a stroke. The potential of tibia to vertical angle as a therapy target

BACKGROUND

Recovering independent walking is a priority for stroke survivors. Community walking requires speeds exceeding the average values typically achieved at discharge (0.7 m/s). To improve outcomes there is a need to clarify the factors associated with recovery of functional walking speeds.

RESEARCH QUESTION

Which biomechanical variables correlate significantly with improved walking speed following rehabilitation in acute stroke patients.

METHODS

The study was embedded in a larger clinical trial testing efficacy of a gait training splint. Participants, within 6 weeks of their stroke and exhibiting abnormal gait, were recruited. Using a valid and reliable video-based system, specific kinematic measures were recorded before randomisation (baseline), after a 6-week rehabilitation phase (outcome) and six months after stroke (follow-up). Measures of temporospatial symmetry, knee angular velocity and tibia to vertical angle were added to clinical measures and correlated with change in speed.

RESULTS

23 participants were recruited, (mean age 67.7 ± 16.7 years, 19.2 ± 9.0 days after stroke and 73.9% male), with 20/23 assessed at outcome and 17/23 at follow-up. Drop out was due to withdrawal (3) and technical failure (3). Walking speed increased by 0.15 ± 0.21 m/s (outcome), and 0.21 ± 0.14 m/s (follow-up) from baseline (0.50 ± 0.20 m/s). This increase correlated with an increase in step length (r=0.88) and change in angle of tibia at initial contact (r=-0.59), foot flat (r=-0.61) and terminal contact (r=0.54).

SIGNIFICANCE

This study of gait recovery among acute stroke patients demonstrated modest improvements in walking speed. Walking speed by follow-up (0.71 m/s) classified the group as community walkers (>0.66 m/s) but still too slow to safely use a pedestrian road crossing. Change in step length and tibia to vertical angle significantly correlated with increased walking speed. This finding provides distinctive targets for therapy aimed at improving community walking among stroke survivors. This hypothesis should be tested prospectively in future studies.

The Association between Four Gait Speed Assessments and Incident Stroke in Older Adults: The Health, Aging and Body Composition Study

OBJECTIVE

To examine the association between gait speed and incident stroke and compare the predictive value between four gait speed assessments (6-meter, 20-meter, 2-min, and 400-meter).

DESIGN

Prospective cohort study.

SETTING

1,779 older adults from the Health, Aging and Body Composition study. All participants had no history of cardiovascular or cerebrovascular disease at baseline.

METHODS

We used Cox proportional hazards regression model to identify the relationship between each of four gait speed assessment and incident stroke. We used the c-statistic, Akaike information criterion (AIC), and Bayesian information criterion (BIC) to compare the predictive validity between four measures.

RESULTS

176 (9.9%) had incident stroke during an average 10.3-year follow-up. After multivariable adjustment, hazard ratio of incident stroke was 0.89 (95% CI: 0.82-0.97), 0.90 (95%CI: 0.82-0.98), 0.88 (95% CI: 0.80-0.97), and 0.86 (95% CI: 0.78-0.95) for 6-meter, 20-meter, 2-min, and 400-meter test, respectively. We found only negligible difference in the c-statistic between four gait speed assessments (range: 0.66-0.67). Similarly, we did not observe huge difference in AIC or BIC between four assessments.

CONCLUSIONS

Gait speed was independently associated with stroke among older adults. Different gait speed assessments had similar prognostic value for predicting stroke.

Effects of horse-riding therapy and rhythm and music-based therapy on functional mobility in late phase after stroke

BACKGROUND

Persons with stroke commonly have residual neurological deficits that seriously hamper mobility.

OBJECTIVE

To investigate whether horse-riding therapy (H-RT) and rhythm and music-based therapy (R-MT) affect functional mobility in late phase after stroke.

METHODS

This study is part of a randomized controlled trial in which H-RT and R-MT was provided twice weekly for 12 weeks. Assessment included the timed 10-meter walk test (10 mWT), the six-minute walk test (6 MWT) and Modified Motor Assessment Scale (M-MAS).

RESULTS

123 participants were assigned to H-RT (n = 41), R-MT (n = 41), or control (n = 41). Post-intervention, the H-RT group completed the 10 mWT faster at both self-selected (-2.22 seconds [95% CI, -3.55 to -0.88]; p = 0.001) and fast speed (-1.19 seconds [95% CI, -2.18 to -0.18]; p = 0.003), with fewer steps (-2.17 [95% CI, -3.30 to -1.04]; p = 0.002 and -1.40 [95% CI, -2.36 to -0.44]; p = 0.020, respectively), as compared to controls. The H-RT group also showed improvements in functional task performance as measured by M-MAS UAS (1.13 [95% CI, 0.74 to 1.52]; p = 0.001). The gains were partly maintained at 6 months among H-RT participants. The R-MT did not produce any immediate gains. However, 6 months post-intervention, the R-MT group performed better with respect to time; -0.75 seconds [95% CI, -1.36 to -0.14]; p = 0.035) and number of steps -0.76 [95% CI, -1.46 to -0.05]; p = 0.015) in the 10 mWT at self-selected speed.

CONCLUSIONS

The present study supports the efficacy of H-RT in producing immediate gains in gait and functional task performance in the late phase after stroke, whereas the effectiveness of R-MT is less clear.

Application of the Gait Deviation Index in the analysis of post-stroke hemiparetic gait

Due to the complexity and volume of kinematic data from 3-dimensional gait analysis, the Gait Deviation Index (GDI) was introduced as a summary measure providing a global picture of gait kinematic data, however previously it was not validated as an outcome measure in individuals after stroke. The present study investigated the concurrent validity of the GDI as an outcome measure of gait defects at a chronic stage of recovery post-stroke, through comparisons with conventional measures of gait. Those enrolled included 65 individuals after stroke and 65 healthy individuals without gait disorders, matched for age and gender. The kinematic gait parameters were measured using a movement analysis system. Walking speed, walking distance, number of steps, self-reliant mobility, cadence, step length, and single support time were evaluated. Strong correlation was found between cadence and mGDI as well as GDI for the affected leg (0.7 ≤ |R| < 0.9; p < 0.001). Moderate correlations were found between walking speed, number of steps, step length affected leg and mGDI as well as GDI for the affected leg (0.5 ≤ |R| < 0.7; p < 0.001). Low correlations were found between walking distance, self-reliant mobility, single support time affected leg and mGDI as well as GDI for the affected leg (0.3 ≤ |R| < 0.5; p < 0.001; p < 0.005). The findings confirm the concurrent validity of the GDI, but only for the affected leg and mGDI in post-stroke patients. On the other hand, the GDI for unaffected leg may be useful in efforts to identify any compensatory mechanisms developing in post-stroke gait patterns. Trial registration: anzctr.org.au, ID:ACTRN12617000436370. Registered 24 March 2017.