Deficit and change in gait velocity during rehabilitation after stroke

Effects of robot-assisted walking training on balance, motor function, and ADL depending on severity levels in stroke patients

BACKGROUND

Despite the explosive increase in interest regarding Robot-Assisted Walking Training (RAWT) for stroke patients, very few studies have divided groups according to the severity levels of patients and conducted studies on the effects of RAWT.

OBJECTIVE

The purpose of this study was to present a definite basis for physical therapy using the robot-assisted walking device through a more detailed comparison and analysis and to select the optimal target of RAWT.

METHODS

This study was designed as a prospective and randomized controlled trial to investigate the effect of RAWT on balance, motor function, and Activities of Daily Living (ADL) depending on severity levels in stroke patients. 100 participants were randomly divided into study and control groups in equal numbers. The study group was 49 and the control group was 47. One from the study group and three from the control group were eliminated. The study period is four weeks in total, and RAWT is performed five times a week for 40 minutes only for study group. During the same period, all group members had 30 minutes of Conventional Physiotherapy (CP) five times a week.

RESULTS

The results of this study clearly confirmed that RAWT combined with CP produces more significant improvement in patients with stroke than the CP alone. And they indicated that RAWT had a more considerable effect in the poor or fair trunk control group for trunk balance and in the high fall risk group for balance. In motor function, RAWT showed its value in the severe and marked motor impairment group. The total or severe dependence group in ADL experienced more improvements for RAWT.

CONCLUSION

This study can be concluded that the lower the level of physical functions, the more effective it responds to RAWT. As demonstrated in the results of this study, the potential of current robotic technology appears to be greatest at very low functional levels of stroke patients. Patients with low functional levels among stroke patients may benefit from robot rehabilitation.

Effects of rehabilitation exercise program types on dynamic balance in patients with stroke: a meta-analysis of randomized controlled trials

PURPOSE

The purposes of meta-analysis are to evaluate evidence about the effects of Rehabilitation Exercise Program on the balance of post-stroke patients, evaluated by the Berg Balance Scale (BBS).

METHODS

The search was conducted 'stroke,' 'rehabilitation,' 'dynamic balance,' 'Berg Balance Scale,' 'exercise' and 'randomized controlled trial'using MEDLINE (accessed by PubMed), Web of Science (WoS), ProQuest, and Google Scholar for journal studies published from January 2018 to October 2022. Two independent reviewers performed the article selection, data extraction, and methodological quality assessment. The main outcome was dynamic balance assessed by the Berg Balance scale.

RESULTS

The review included 30 papers and a total of 540 patients. The overall effect size was 0.550, a medium effect size according to the Cohen's standard. It was observed that gender has moderate effect size in male (0.551), female (0.458) and higher in male. Exercise type results showed large effect sizes in balance training (0.966), and aquatic activities (0.830), moderate effect sizes in virtual reality (0.762), moderate effect sizes in physically active (0.581), gait training (0.541), dual-task (0.478), trunk control (0.284), and small effect sizes in resistance training (0.128).

CONCLUSIONS

Exercise programs are effective in improving dynamic balance in stroke patients. Especially, the meta-analysis showed higher Effect Size for balance training and virtual reality than for other programs making this relevant interventions for future head to head superiority studies that compare different balance interventions in stroke.

Biochemical, biomechanical and imaging biomarkers of ischemic stroke: Time for integrative thinking

Stroke is one of the leading causes of adult disability affecting millions of people worldwide. Post-stroke cognitive and motor impairments diminish quality of life and functional independence. There is an increased risk of having a second stroke and developing secondary conditions with long-term social and economic impacts. With increasing number of stroke incidents, shortage of medical professionals and limited budgets, health services are struggling to provide a care that can break the vicious cycle of stroke. Effective post-stroke recovery hinges on holistic, integrative and personalized care starting from improved diagnosis and treatment in clinics to continuous rehabilitation and support in the community. To improve stroke care pathways, there have been growing efforts in discovering biomarkers that can provide valuable insights into the neural, physiological and biomechanical consequences of stroke and how patients respond to new interventions. In this review paper, we aim to summarize recent biomarker discovery research focusing on three modalities (brain imaging, blood sampling and gait assessments), look at some established and forthcoming biomarkers, and discuss their usefulness and complementarity within the context of comprehensive stroke care. We also emphasize the importance of biomarker guided personalized interventions to enhance stroke treatment and post-stroke recovery.

Putting the fear-avoidance model into practice - what can patients with chronic low back pain learn from patients with Achilles tendinopathy and vice versa?

BACKGROUND

Fear-avoidance variables are present in patients with musculoskeletal pain conditions, such as chronic low back pain (CLBP) and Achilles tendinopathy (AT) and can lead to reduced function and recovery. It is unknown how these variables relate in populations with different etiologies but similar pain provocation mechanisms.

OBJECTIVE

To compare kinesiophobia, pain catastrophizing, and disability between these two groups.

METHODS

Patients with CLBP and those with AT were included. Tampa Scale of Kinesiophobia (TSK-17) and Pain Catastrophizing Scale (PCS-13) were evaluated in both groups. The CLBP group completed the Oswestry Disability Index (ODI) and the AT group completed the PROMIS-29 questionnaire. Gait speed was calculated for each group. Disability outcomes were normalized between groups.

RESULTS

119 patients in the CLBP group (64 female, 46 ± 8 years) and 83 patients in the AT group (42 female, 48 ± 12 years) were included. Both groups (CLBP, AT) presented with high prevalence of kinesiophobia (67%, 55%) but the CLBP group presented with higher prevalence of pain catastrophizing (22%, 2%). The CLBP group demonstrated higher levels of disability via normalized ODI (MD= 12.4, 95% CI: 9.2, 15.5) but the AT group demonstrated slower gait speed (MD= 0.1 m/s, 95% CI: 0.0, 0.2).

CONCLUSION

Similarly high prevalence of kinesiophobia was found in patients with CLBP and patients with AT. While the CLBP group reported greater prevalence of catastrophizing thoughts and greater disability, the AT group had slower gait speed. Overall, these findings demonstrate that CLBP and AT have similarities that may allow clinicians to learn from one to inform treatment of the other.

CLINICAL TRIAL REGISTRATION NUMBERS

NCT03523325, ISRCTN17115599.

Neurophysiology of cerebellar ataxias and gait disorders

There are numerous forms of cerebellar disorders from sporadic to genetic diseases. The aim of this chapter is to provide an overview of the advances and emerging techniques during these last 2 decades in the neurophysiological tests useful in cerebellar patients for clinical and research purposes. Clinically, patients exhibit various combinations of a vestibulocerebellar syndrome, a cerebellar cognitive affective syndrome and a cerebellar motor syndrome which will be discussed throughout this chapter. Cerebellar patients show abnormal Bereitschaftpotentials (BPs) and mismatch negativity. Cerebellar EEG is now being applied in cerebellar disorders to unravel impaired electrophysiological patterns associated within disorders of the cerebellar cortex. Eyeblink conditioning is significantly impaired in cerebellar disorders: the ability to acquire conditioned eyeblink responses is reduced in hereditary ataxias, in cerebellar stroke and after tumor surgery of the cerebellum. Furthermore, impaired eyeblink conditioning is an early marker of cerebellar degenerative disease. General rules of motor control suggest that optimal strategies are needed to execute voluntary movements in the complex environment of daily life. A high degree of adaptability is required for learning procedures underlying motor control as sensorimotor adaptation is essential to perform accurate goal-directed movements. Cerebellar patients show impairments during online visuomotor adaptation tasks. Cerebellum-motor cortex inhibition (CBI) is a neurophysiological biomarker showing an inverse association between cerebellothalamocortical tract integrity and ataxia severity. Ataxic gait is characterized by increased step width, reduced ankle joint range of motion, increased gait variability, lack of intra-limb inter-joint and inter-segmental coordination, impaired foot ground placement and loss of trunk control. Taken together, these techniques provide a neurophysiological framework for a better appraisal of cerebellar disorders.

Development of an assessment of bilateral locomotor efficacy for individuals post-stroke

BACKGROUND

A common framework is needed to assess walking impairments in older adults and individuals with stroke. This study develops an Assessment of Bilateral Locomotor Efficacy (ABLE) that is a straightforward indicator of walking function.

RESEARCH QUESTION

Can we develop a clinically accessible index of walking function that summarizes gait dysfunction secondary to stroke?

METHODS

The ABLE index was developed using a retrospective sample of 14 community-dwelling older adults. Data from 33 additional older adults and 105 individuals with chronic post-stroke hemiparesis were used to validate the index by factor analysis of the score components and correlation with multiple common assessments of lower extremity impairment and function.

RESULTS

The ABLE consists of four components summed for a maximum possible score of 12. The components include self-selected walking speed (SSWS), speed change from SSWS to fastest speed, non-paretic leg step length change from SSWS to fastest speed, and peak paretic leg ankle power. The ABLE revealed good concurrent validity with all recorded functional assessments. Factor analysis suggested that the ABLE measures two factors: one for forward progression and another for speed adaptability.

SIGNIFICANCE

The ABLE offers a straightforward, objective measure of walking function in adults, including individuals with chronic stroke. The index may also prove useful as a screening tool for subclinical pathology in community-dwelling older adults, but further testing is required. We encourage utilization of this index and reproduction of findings to adapt and refine the instrument for wider use and eventual clinical application.

The effect of robot-assisted walking in different modalities on cardiorespiratory responses and energy consumption in patients with subacute stroke

OBJECTIVES

The aim of our study was to evaluate the effect of robot-assisted walking in different modalities on cardiorespiratory responses and energy consumption in subacute stroke patients.

METHODS

Our study consisted of 16 individuals between the ages of 18-65 years. Individuals diagnosed with hemiplegia after unilateral ischemic or haemorrhagic stroke constitute the stroke group. Eight subacute stroke individuals were included in the experimental group, and eight healthy individuals were included in the control group. Each participant tested on the Lokomat in three consecutive days in random sequence, with three tests: the first test: 100% guiding strength (GF)and 100% body weight support (BWS); the second test 80% GF, 50% BWS; the third test 60% GF, 30% BWS was achieved. Gas analyzer (Cosmed, Quark CPET, Italy) measurements were made with the help of a mask to evaluate the cardiorespiratory responses of the participants during all tests.

RESULTS

In the comparison of the three test results of the two groups separately, the stroke group's oxygen consumption (VO2), carbon dioxide production (VCO2), tidal volume (VT), pulse reserve (HRR), calories burned per hour (EEh), Borg dyspnea values, control group's VO2, VCO2, VE, HR, HRR, and EEh, Borg values were statistically significantly different (p < 0.005). It was seen that the third test results were significantly greater than the first and second test results (p < 0.005).

DISCUSSION

By decreasing GF and BWS values during robot-assisted walking, adequate cardio-metabolic and energy response in both subacute stroke patients and healthy individuals could be achieved. These results show us that it is important to consider the cardiorespiratory function of the patient when choosing training protocols.

Effectiveness of an 8-week overground walking with paretic lower limb loading on spatiotemporal gait parameters and motor function among chronic stroke survivors: a protocol for randomised controlled trial

BACKGROUND

Post-stroke gait deviations contribute to significant functional disability, impaired walking ability and poor quality of life. Prior studies suggest that gait training with paretic lower limb loading may improve gait parameters and walking ability in post-stroke. However, most gait training methods used in these studies are not readily available, and studies using cheaper methods are limited.

OBJECTIVE

The purpose of this study is to describe a protocol for a randomised controlled trial on the effectiveness of an 8-week overground walking with paretic lower limb loading on spatiotemporal gait parameters and motor function among chronic stroke survivors.

METHODS

This is a two-center, single-blind, two-arm parallel randomised controlled trial. Forty-eight stroke survivors with mild to moderate disability will be recruited from two tertiary facilities and randomly assigned into two intervention arms; overground walking with paretic lower limb loading or overground walking without paretic lower limb loading in a 1:1 ratio. All interventions will be administered thrice weekly for 8 weeks. Primary outcomes will be step length and gait speed whereas the secondary outcomes will include step length symmetry ratio, stride length, stride length symmetry ratio, stride width, cadence and motor function. All outcomes will be assessed at baseline, 4, 8 and 20 weeks after the start of intervention.

DISCUSSION

This will be the first randomised controlled trial to report the effects of overground walking with paretic lower limb loading on spatiotemporal gait parameters and motor function among chronic stroke survivors from low-resource setting.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05097391. Registered on 27 October 2021.

A Comparison of Force-Plate Based Center of Mass Estimation Algorithms

Estimating horizontal center of mass (CoM) is an important process that is used in the control of self-paced treadmills, as well as in clinical and scientific biomechanical analysis. Many laboratories use motion-capture to estimate CoM, while others use force-plate based estimates, either because they cannot access motion-capture or they do not want to be taxed with post-processing optoelectronic data. Three force-plate derived center of mass estimation algorithms were compared against a benchmark motion-capture technique. Two of them have recently been reported in the literature, and both rely on numerical integration of 2nd-order differential equations. We propose a third technique that uses an algebraic equation to directly relate center of pressure to center of mass without numerical drift. Twenty-four healthy adults participated in a five-minute steady-state walking test to compare these algorithms. The sample-by-sample standard deviation of the three force-plate based algorithms from the motion-capture benchmark algorithm was evaluated. The algebraic technique provided less error than either of the two more common integration techniques (p<0.05). The results of this study support the viability of using only ground reaction forces for self-paced treadmills and also show that a simple algebraic model is preferred to integration approaches. The use of an algebraic estimation simplifies control implementation for self-paced treadmill applications and eliminates the need for event-based drift recalibration.

Real-World Walking Speed Assessment Using a Mass-Market RTK-GNSS Receiver

Walking speed is an important clinical parameter because it sums up the ability to move and predicts adverse outcomes. However, usually measured inside the clinics, it can suffer from poor ecological validity. Wearable devices such as global positioning systems (GPS) can be used to measure real-world walking speed. Still, the accuracy of GPS systems decreases in environments with poor sky visibility. This work tests a solution based on a mass-market, real-time kinematic receiver (RTK), overcoming such limitations. Seven participants walked a predefined path composed of tracts with different sky visibility. The walking speed was calculated by the RTK and compared with a reference value calculated using an odometer and a stopwatch. Despite tracts with totally obstructed visibility, the correlation between the receiver and the reference system was high (0.82 considering all tracts and 0.93 considering high-quality tracts). Similarly, a Bland Altman analysis showed a minimal detectable change of 0.12 m/s in the general case and 0.07 m/s considering only high-quality tracts. This work demonstrates the feasibility and validity of the presented device for the measurement of real-world walking speed, even in tracts with high interference. These findings pave the way for clinical use of the proposed device to measure walking speed in the real world, thus enabling digital remote monitoring of locomotor function. Several populations may benefit from similar devices, including older people at a high risk of fall, people with neurological diseases, and people following a rehabilitation intervention.

Change in knee cartilage components in stroke patients with genu recurvatum analysed by zero TE MR imaging

Genu recurvatum in stroke patients with hemiplegia causes readily cumulative damage and degenerative changes in the knee cartilage. It is important to detect early cartilage lesions for appropriate treatment and rehabilitation. The purpose of this cross-sectional study was to provide a theoretical basis for the early rehabilitation of hemiplegia patients. We used a zero TE double-echo imaging sequence to analyse the water content in knee joint cartilage at 12 different sites of 39 stroke patients with genu recurvatum and 9 healthy volunteers using a metric similar to the porosity index. When comparing the hemiplegic limb vs. the nonhemiplegic limb in patients, the ratios of the deep/shallow free water content of the femur cartilages at the anterior horn (1.16 vs. 1.06) and posterior horn (1.13 vs. 1.25) of the lateral meniscus were significantly different. Genu recurvatum in stroke patients with hemiplegia can cause changes in the moisture content of knee cartilage, and the changes in knee cartilage are more obvious as the genu recurvatum increases. The "healthy limb" can no longer be considered truly healthy and should be considered simultaneously with the affected limb in the development of a rehabilitation treatment plan.

The Microsoft HoloLens 2 Provides Accurate Measures of Gait, Turning, and Functional Mobility in Healthy Adults

Augmented-reality (AR) headsets, such as the Microsoft HoloLens 2 (HL2), have the potential to be the next generation of wearable technology as they provide interactive digital stimuli in the context of ecologically-valid daily activities while containing inertial measurement units (IMUs) to objectively quantify the movements of the user. A necessary precursor to the widespread utilization of the HL2 in the fields of movement science and rehabilitation is the rigorous validation of its capacity to generate biomechanical outcomes comparable to gold standard outcomes. This project sought to determine equivalency of kinematic outcomes characterizing lower-extremity function derived from the HL2 and three-dimensional (3D) motion capture systems (MoCap). Sixty-six healthy adults completed two lower-extremity tasks while kinematic data were collected from the HL2 and MoCap: (1) continuous walking and (2) timed up-and-go (TUG). For all the continuous walking metrics (cumulative distance, time, number of steps, step and stride length, and velocity), equivalence testing indicated that the HL2 and MoCap were statistically equivalent (error ≤ 5%). The TUG metrics, including turn duration and turn velocity, were also statistically equivalent between the two systems. The accurate quantification of gait and turning using a wearable such as the HL2 provides initial evidence for its use as a platform for the development and delivery of gait and mobility assessments, including the in-person and remote delivery of highly salient digital movement assessments and rehabilitation protocols.

Ambulatory activity in stroke survivors associated with functional outcome and quality of life: an observational cohort study

BACKGROUND

Physical activity is beneficial in stroke prevention and recovery. Understanding activity dynamics and its effect on outcome after stroke is important to improve recommendations and develop interventions.

OBJECTIVES

We examined serial changes in daily ambulatory activity (AA) averaged over 1 week in people with subacute to chronic stroke and its association with functional outcome (modified Rankin scale [mRS]) and quality of life (EQ-5D-3L).

METHODS

This observational study examined AA in stroke survivors with no to moderate disability (US National Institute of Stroke Scale [NIHSS] score) who were mostly community dwelling and had cryptogenic stroke based on data from the Continuous Cardiac Monitoring to Assess Atrial Fibrillation After Cryptogenic Stroke study. The participants underwent long-term AA monitoring by accelerometric activity data obtained from an insertable cardiac monitor without receiving any specific encouragement regarding physical activity. We analysed AA changes and assessed the association between baseline AA and mRS/EQ-5D-3L scores. A small group of participants had follow-up data for 2 years, which allowed for analysing long-term serial changes.

RESULTS

We included 186 participants (mean [SD] age 61.3 [11.2] years, 67% male, mean 39 [28] days after stroke). AA increased during the subacute phase in individuals with mild (NIHSS score 1-4, p<0.001) and moderate (NIHSS score 5-10, p=0.013) disability but not in the non-impaired group. Baseline AA was inversely associated with NIHSS score (p<0.001) and was associated with mRS score (p=0.001) and weakly correlated with EQ-5D-3L score at 6 months (p=0.032, r=0.22). For the 45 participants with follow-up data (mean age 64.5 [9.7] years, 80% male, mean 34 [21] days after stroke), AA remained stable.

CONCLUSION

AA increased in stroke survivors with impairments but remained stable in those whose symptoms had resolved. AA during the early subacute period was associated with mRS and EQ-5D-3L scores at 6 months. Insertable cardiac monitoring offers a feasible method for monitoring activity over prolonged periods in people after stroke. Its increased use may offer an opportunity to overcome the limited reliability and validity of many existing measures.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT00924638).

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.

Change in Center of Pressure Progression in the Foot Provides Clues for Functional Improvement of the More Affected Lower Limb During Post-stroke Gait Rehabilitation

OBJECTIVE

The aim of this study was to determine the clinical significance of the anterior-posterior displacement of the center of pressure in the foot (apCoP) in post-stroke gait rehabilitation.

DESIGN

This observational study was conducted in a tertiary hospital. Forty-two subacute post-stroke patients were included. The apCoP was measured twice with a wearable insole foot pressure measurement system, time interval more than 7 days. The results were compared between the first and second tests. The relationship between apCoP changes and spatiotemporal parameter changes were investigated.

RESULTS

The apCoP increased significantly between tests. The change in walking speed was significantly predicted by the change in the apCoP on the less affected side. The change in asymmetry of the single support phase was significantly correlated with the change in the apCoP on the more affected side.

CONCLUSION

The change in apCoP provides information about the restoration of body support, body forward progression control, and propulsion in the more affected lower limb during early post-stroke rehabilitation. The apCoP can be a useful parameter for the monitoring of functional changes in the more affected lower limb during post-stroke gait rehabilitation.

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.

Does the 1-year Decline in Walking Speed Predict Mortality Risk Beyond Current Walking Speed in Adults With Knee Osteoarthritis?

OBJECTIVE

To investigate whether walking speed at 1 timepoint, decline over the past 12 months, or both predict mortality risk over 11 years in adults with, or at risk of, knee osteoarthritis (OA).

METHODS

Using the data from the Osteoarthritis Initiative, we defined slow versus adequate walking speed as walking < 1.22 versus ≥ 1.22 m/s on a 20m walk test during the 12-month follow-up visit. We defined meaningful decline (yes/no) as slowing ≥ 0.08 m/s over the past year. At the 12-month visit, we classified adequate sustainers as those with adequate walking speed and no meaningful decline, slow sustainers as slow walking speed and no meaningful decline, adequate decliners as adequate walking speed and meaningful decline, and slow decliners as slow walking speed and meaningful decline. Mortality was recorded over 11 years. To examine the association of walking speed with mortality, HR and 95% CI were calculated using Cox regression, adjusted for potential confounders.

RESULTS

Of 4229 participants in the analytic sample (58% female, age 62 ± 9 yrs, BMI 29 ± 5 kg/m²), 6% (n = 270) died over 11 years. Slow sustainers and slow decliners had 2-times increased mortality risk compared to adequate sustainers (HR 1.96, 95% CI 1.44-2.66 for slow sustainers, and HR 2.08, 95% CI 1.46-2.96 for slow decliners). Adequate decliners had 0.43 times the mortality risk compared with adequate sustainers (HR 0.57, 95% CI 0.32-1.01).

CONCLUSION

In adults with, or at risk of, knee OA, walking slower than 1.22 m/s in the present increased mortality risk, regardless of decline over the previous year.

The association between walking speed from short- and standard-distance tests with the risk of all-cause mortality among adults with radiographic knee osteoarthritis: data from three large United States cohort studies

OBJECTIVE

Adults with radiographic knee OA (rKOA) are at increased risk of mortality and walking difficulty may modify this relation. Little is known about specific aspects of walking difficulty that increase mortality risk. We investigated the association of walking speed (objective measure of walking difficulty) with mortality and examined the threshold that best discriminated this risk in adults with rKOA.

METHODS

Participants with rKOA from the Johnston County Osteoarthritis Project (JoCoOA, longitudinal population-based cohort), Osteoarthritis Initiative and Multicenter Osteoarthritis Study (OAI and MOST, cohorts of individuals with or at high risk of knee OA) were included. Baseline speed was measured via 2.4-meter (m) walk test (short-distance) in JoCoOA and 20-m walk test (standard-distance) in OAI and MOST. To examine the association of walking speed with mortality risk over 9 years, hazard ratios (HR) and 95% confidence intervals (CI) were calculated from Cox regression models adjusted for potential confounders. A Maximal Likelihood Ratio Chi-square Approach was utilized to identify an optimal threshold of walking speed predictive of mortality.

RESULTS

Deaths after 9 years of follow-up occurred in 23.3% (290/1244) of JoCoOA and 5.9% (249/4215) of OAI + MOST. Walking 0.2 m/s slower during short- and standard-distance walk tests was associated with 23% (aHR [95%CI]; 1.23 [1.10, 1.39]) and 25% (1.25 [1.09, 1.43]) higher mortality risk, respectively. Walking <0.5 m/s on short-distance and <1.2 m/s standard-distance walk tests, best discriminated those with and without mortality risk.

CONCLUSION

Slower walking speed measured via short- and standard-distance walk tests was associated with increased mortality risk in adults with rKOA.

Responsiveness to change over time and test-retest reliability of the PROMIS and Neuro-QoL mental health measures in persons with Huntington disease (HD)

BACKGROUND

The majority of persons with Huntington disease (HD) experience mental health symptoms. Patient-reported outcome (PRO) measures are capable of capturing unobservable behaviors and feelings relating to mental health. The current study aimed to test the reliability and responsiveness to self-reported and clinician-rated change over time of Neuro-QoL and PROMIS mental health PROs over the course of a 24-month period.

METHODS

At baseline, 12-months, and 24-months, 362 participants with premanifest or manifest HD completed the Neuro-QoL Depression computer adaptive test (CAT), PROMIS Depression short form (SF), Neuro-QoL Anxiety CAT, PROMIS Anxiety SF, PROMIS Anger CAT and SF, Neuro-QoL Emotional/Behavioral Dyscontrol CAT and SF, Neuro-QoL Positive Affect and Well-Being CAT and SF, and Neuro-QoL Stigma CAT and SF. Participants completed several clinician-administered measures at each time point, as well as several global ratings of change at 12- and 24-months. Reliability (test-retest reliability and measurement error) and responsiveness (using standardized response means and general linear models) were assessed.

RESULTS

Test-retest reliability and measurement error were excellent for all PROs (all ICC ≥ .90 for test-retest reliability and all SEM percentages ≤ 6.82%). In addition, 12- and 24-month responsiveness were generally supported for the Neuro-QoL and PROMIS mental health PROs; findings relative to clinician-rated anchors of change (e.g., SRMs for the group with declines ranged from .38 to .91 for 24-month change and .09 to .45, with the majority above .25 for 12-month change) were generally more robust than those relative to self-reported anchors of change (e.g., SRMs for the group with declines ranged from .02 to .75, with the majority above .39 for 24-month change and .09 to .45, with the majority above .16 for 12-month change).

CONCLUSIONS

The Neuro-QoL and PROMIS mental health PROs demonstrated strong psychometric reliability, as well as responsiveness to self-reported and clinician-rated change over time in people with HD.

Characterization of speed adaptation while walking on an omnidirectional treadmill

BACKGROUND

Conventional treadmills are widely used for gait retraining in rehabilitation setting. Their usefulness for training more complex locomotor tasks, however, remains limited given that they do not allow changing the speed nor the direction of walking which are essential walking adaptations for efficient and safe community ambulation. These drawbacks can be addressed by using a self-pace omnidirectional treadmill, as those recently developed by the gaming industry, which allows speed changes and locomotor movements in any direction. The extent to which these treadmills yield a walking pattern that is similar to overground walking, however, is yet to be determined.

METHODS

The objective of this study was to compare spatiotemporal parameters, body kinematics and lower limb muscle activation of healthy young individuals walking at different speeds (slow, comfortable, fast) on a low-cost non-motorized omnidirectional treadmill with and without virtual reality (VR) vs. overground.

RESULTS

Results obtained from 12 young healthy individuals (18-29 years) showed that participants achieved slower speed on the treadmill compared to overground. On the treadmill, faster walking speeds were achieved by a mere increase in cadence, as opposed to a combined increase in cadence and step length when walking overground. At matched speed, enhanced stance phase knee flexion, reduced late stance ankle plantarflexion, as well as enhanced activation amplitudes of hip extensors in late stance and hip extensors in early swing were observed. The addition of VR to treadmill walking had little or no effect of walking outcomes. Collectively, results show that the omnidirectional treadmill yields a different walking pattern and lead to different adaptations to speed compared to overground walking. We suggest that these alterations are mainly driven by the reduced shear forces between the weight bearing foot and supporting surface and a perceived threat to balance on the omnidirectional treadmill.

CONCLUSION

Since such treadmills are likely to be used for prolonged periods of time by gamers or patients undergoing physical rehabilitation, further research should aim at determining the impact of repeated exposure on gait biomechanics and lower limb musculoskeletal integrity.

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.

A Narrative Review on Measurement Properties of Fixed-distance Walk Tests Up to 40 Meters for Adults With Knee Osteoarthritis

Knee osteoarthritis (OA) is a serious disease and has no cure to date. Knee OA is a leading cause of functional limitation (e.g., difficulty walking). Walking speed is 1 method of quantifying difficulty with walking and should be assessed in clinical practice for adults with knee OA because it has prognostic value and is modifiable. Specifically, slow walking speed is associated with increased risk of adverse health outcomes, including all-cause mortality in adults with knee OA and can be modified by engaging in physical activity or exercise. However, at present, there is little consensus on the distance and instructions used to conduct the walk test. Distance is often selected based on space availability, and instruction varies, from asking the participants to walk at a comfortable pace versus as fast as possible. Therefore, the purpose of this narrative review is to summarize the measurement properties, strengths, and limitations of a fixed-distance walk test ≤ 40 meters in adults with knee OA. Good measurement properties in terms of reliability and validity were observed across the different testing protocols for fixed-distance walk test (i.e., any distance ≤ 40 m and fast- or self-paced). Therefore, clinicians and researchers can select a testing protocol that can safely and consistently be performed over time, as well as provide a practice trial to acclimatize the patients to the fixed-distance walk test.

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.

Using force data to self-pace an instrumented treadmill and measure self-selected walking speed

BACKGROUND

Self-selected speed is an important functional index of walking. A self-pacing controller that reliably matches walking speed without additional hardware can be useful for measuring self-selected speed in a treadmill-based laboratory.

METHODS

We adapted a previously proposed self-pacing controller for force-instrumented treadmills and validated its use for measuring self-selected speeds. We first evaluated the controller's estimation of subject speed and position from the force-plates by comparing it to those from motion capture data. We then compared five tests of self-selected speed. Ten healthy adults completed a standard 10-meter walk test, a 150-meter walk test, a commonly used manual treadmill speed selection test, a two-minute self-paced treadmill test, and a 150-meter self-paced treadmill test. In each case, subjects were instructed to walk at or select their comfortable speed. We also assessed the time taken for a trial and a survey on comfort and ease of choosing a speed in all the tests.

RESULTS

The self-pacing algorithm estimated subject speed and position accurately, with root mean square differences compared to motion capture of 0.023 m s -1 and 0.014 m, respectively. Self-selected speeds from both self-paced treadmill tests correlated well with those from the 10-meter walk test (R>0.93,p<1×10-13). Subjects walked slower on average in the self-paced treadmill tests (1.23±0.27 ms-1) than in the 10-meter walk test (1.32±0.18 ms-1) but the speed differences within subjects were consistent. These correlations and walking speeds are comparable to those from the manual treadmill speed selection test (R=0.89,p=3×10-11;1.18±0.24 ms-1). Comfort and ease of speed selection were similar in the self-paced tests and the manual speed selection test, but the self-paced tests required only about a third of the time to complete. Our results demonstrate that these self-paced treadmill tests can be a strong alternative to the commonly used manual treadmill speed selection test.

CONCLUSIONS

The self-paced force-instrumented treadmill well adapts to subject walking speed and reliably measures self-selected walking speeds. We provide the self-pacing software to facilitate use by gait researchers and clinicians.

The effect of simulated circumferential soft exoskeleton compression at the knee on discomfort and pain

There is a lack of data and guidance on soft exoskeleton pressure contact with the body. The purpose of this research was to study the relationship between circumferential loading at the knee and discomfort/pain, to inform the design of soft exoskeletons/exosuits. The development of discomfort and pain was studied during standing and walking with circumferential compression using a pneumatic cuff. Our results show higher tolerance for intermittent than continuous compression during standing. Discomfort was triggered at pressures ranging from 13.7 kPa (continuous compression) to 30.4 kPa (intermittent compression), and pain at 52.9 kPa (continuous compression) to 60.6 kPa (intermittent compression). During walking, cyclic compression caused an increase in discomfort with time. Higher cuff inflation pressures caused an earlier onset and higher end intensities of discomfort than lower pressures. Cyclic cuff inflation of 10 kPa and 20 kPa was reasonably well tolerated. Practitioner summary Soft exoskeleton compression of the knee was simulated during static and dynamic compression cycles. The results can be used to understand how users tolerate pressure at the knee, and also to understand the levels at which discomfort and pain are experienced. Abbreviations: BMI: body mass index; DDT: discomfort detection threshold; EndVAS: end of experiment rating on visual analog discomfort scale; PDT: pain detection threshold; SD: standard deviation; SE: standard error; TSP: temporal summation of pain; VAS: visual analogue scale.

Functional ambulatory status as a potential adjunctive decision-making tool following wound, level of ischemia, and severity of foot infection assessment

The Society for Vascular Surgery Lower Extremity Threatened Limb Classification System has been developed to stratify amputation risk on the basis of extent of the wound, level of ischemia, and severity of foot infection (WIfI). However, there are no currently validated metrics to assess, grade, and consider functional status, especially ambulatory status, as a major consideration during limb salvage efforts. Therefore, we propose an adjunct to the current WIfI system to include the patient's ambulatory functional status after initial assessment of limb threat. We propose a functional ambulatory score divided into grade 0, ambulation outside the home with or without an assistive device; grade 1, ambulation within the home with or without an assistive device; grade 2, minimal ambulation, limbs used for transfers; and grade 3, a person who is bed-bound. Adding ambulatory function as a supplementary assessment tool can guide clinical decision making to achieve optimal future functional ambulatory outcome, a patient-centered goal as critical as limb preservation. This adjunct may aid limb preservation teams in rapid, effective communication and clinical decision making after initial WIfI assessment. It may also improve efforts toward patient-centered care and functional ambulatory outcome as a primary objective. We suggest a score of functional ambulatory status should be included in future trials of patients with chronic limb-threatening ischemia.

The reproducibility and responsiveness of subjective assessment of upper limb associated reactions in people with acquired brain injury during walking

Objective:

The aim of this study is to determine inter-rater, test–retest and intra-rater reproducibility and responsiveness of subjective assessment of upper limb associated reactions in people with acquired brain injury using (1) the ‘Qualifiers Scale’ of the International Classification of Functioning, Disability and Health Framework, and (2) visually estimated elbow flexion angle during walking.

Design:

Observational study.

Setting:

A brain injury rehabilitation centre, Melbourne, Australia.

Subjects:

People with acquired brain injury and upper limb associated reactions and experienced neurological physiotherapists.

Main measures:

The Qualifiers Scale applied to individual upper limb joints and global associated reaction on a 5-point scale (0–4), a summed upper limb severity score and visually estimated elbow flexion angle.

Results:

A total of 42 people with acquired brain injury (mean age: 48.4 ± 16.5 years) were videoed walking at self-selected and fast speeds. A subset of 30 chronic brain injury participants (mean time post injury: 8.2 ± 9.3 years) were reassessed one week later for retest reproducibility. Three experienced neurological physiotherapists (mean experience: 22.7 ± 9.1 years) viewed these videos and subjectively rated the upper limb associated reactions. Strong-to-very strong test–retest, intra- and inter-rater reproducibility was found for elbow flexion angle (ICC > 0.86) and the Qualifiers Scale applied to global and individual upper limb joints (ICC > 0.60). Responsiveness of change from self-selected to fast walking speed (mean increase 0.46 m/s) was highest for elbow flexion angle (effect size = 0.83) and low-to-moderate for the Qualifiers Scale.

Conclusion:

Subjectively rated associated reactions during walking demonstrated strong reproducibility and moderate responsiveness to speed change. The Qualifiers Scale and elbow flexion angle can both subjectively quantify associated reactions during walking in a clinical setting.

The long-term effects of an implantable drop foot stimulator on gait in hemiparetic patients

Drop foot is a frequent abnormality in gait after central nervous system lesions. Different treatment strategies are available to functionally restore dorsal extension during swing phase in gait. Orthoses as well as surface and implantable devices for electrical stimulation of the peroneal nerve may be used in patients who do not regain good dorsal extension. While several studies investigated the effects of implanted systems on walking speed and gait endurance, only a few studies have focussed on the system’s impact on kinematics and long-term outcomes. Therefore, our aim was to further investigate the effects of the implanted system ActiGait on gait kinematics and spatiotemporal parameters for the first time with a 1-year follow-up period. 10 patients were implanted with an ActiGait stimulator, with 8 patients completing baseline and follow-up assessments. Assessments included a 10-m walking test, video-based gait analysis and a Visual Analogue Scale (VAS) for health status. At baseline, gait analysis was performed without any assistive device as well as with surface electrical stimulation. At follow-up patients walked with the ActiGait system switched off and on. The maximum dorsal extension of the ankle at initial contact increased significantly between baseline without stimulation and follow-up with ActiGait (p = 0.018). While the spatio-temporal parameters did not seem to change much with the use of ActiGait in convenient walking speed, patients did walk faster when using surface stimulation or ActiGait compared to no stimulation at the 10-m walking test at their fastest possible walking speed. Patients rated their health better at the 1-year follow-up. In summary, a global improvement in gait kinematics compared to no stimulation was observed and the long-term safety of the device could be confirmed.

Gait Profile Score in able-bodied and post-stroke individuals adjusted for the effect of gait speed

BACKGROUND

The Gait Profile Score (GPS) measures the quality of an individual's walking by calculating the difference between the kinematic pattern and the average walking pattern of healthy individuals.

RESEARCH QUESTIONS

The purposes of this study were to quantify the effect of speed on the GPS and to determine whether the prediction of gait patterns at a specific speed would make the GPS outcome insensitive to gait speed in the evaluation of post-stroke individuals.

METHODS

The GPS was calculated for able-bodied individuals walking at different speeds and for the comparison of post-stroke individuals with able-bodied individuals using the original experimental data (standard GPS) and the predicted gait patterns at a given speed (GPS velocity, GPS^v). We employed standard gait analysis for data collection of the subjects. Sixteen participants with a stroke history were recruited for the post-stroke group, and 15 age-matched, able-bodied participants formed the control group.

RESULTS

Gait speed significantly affects the GPS and the method to predict the gait patterns at any speed is able to mitigate the effects of gait speed on the GPS. Overall, the gap between the GPS and GPS^v values across the post-stroke individuals was small (0.5° on average, range from 0.0° to 1.4°) and not statistically significant. However, there was a significant negative linear relationship in the absolute difference between the GPS and GPS^v values for the participants of the post-stroke group with gait speed, indicating that a larger difference between the speeds of the post-stroke participant and the reference dataset resulted in a larger difference between the GPS and GPS^v.

SIGNIFICANCE

The modified version of the GPS, the GPS^v, is effective in reducing the impact of gait speed on GPS; however, the observed difference between the two methods was only around 1° for the slowest individuals in comparison to the reference dataset.

Factors Affecting Walking Speed in Schizophrenia Patients

Objective

This study investigated the factors affecting walking speed in schizophrenia patients who were inpatients at a psychiatric hospital.

Methods

The study subjects were 37 patients with schizophrenia who were hospitalized in a psychiatric hospital. The measured assessment items included age, duration of hospitalization, duration of disease, muscle strength (30-s chair stand test), balance ability (one-leg standing time with eyes open/closed, Functional Reach Test, and Timed Up & Go Test), flexibility (long sitting position toe-touching distance), walking speed (10-m maximum walking speed), and the antipsychotic drug intake.

Results

The walking speed was found to be correlated with the results of the 30-s chair stand test, the one-leg standing time with eyes open, the one-leg standing time with eyes closed, and the Timed Up & Go Test. Stepwise multiple regression analysis revealed that only the Timed Up & Go Test results affected walking speed.

Conclusion

In schizophrenia patients, walking speed is influenced by balance and lower-limb muscle force, just as it is for patients without mental diseases. In schizophrenia patients, the dynamic balance ability has a strong influence on the walking speed.

Practice Variability Combined with Task-Oriented Electromyographic Biofeedback Enhances Strength and Balance in People with Chronic Stroke

Objectives

To investigate the effects of practice variability combined with task-oriented electromyographic biofeedback (EMGBFB) on strength and balance in people with chronic stroke.

Methods

Thirty-three participants were randomly assigned into the constant force EMGBFB tibialis anterior (TA) exercise (constant) group, the variable force EMGBFB tibialis anterior exercise (variable) group, or the upper extremity exercise without EMGBFB (control) group. Subjects in each group received 6 weekly sessions of exercise training (18 sessions, 40 minutes each). Motor outcomes were TA strength, balance (anteroposterior sway amplitude defined by limits of stability test in dynamic posturography), walking speed, Timed Up and Go test (TUGT), and six-minute walk test (6MWT). Data were measured at baseline, 1 day, 2 weeks, and 6 weeks posttraining.

Results

TA strength increased significantly in both the constant and variable groups after training. Balance significantly improved only in the variable group. All participants showed improvements in walking speed, TUGT, and 6MWT.

Conclusions

Task-oriented EMGBFB-assisted TA exercise training improved muscle strength in people with chronic stroke. Practicing to reach varying force levels during EMGBFB-assisted tibialis anterior exercises facilitated improvements in the ability to sway in the anteroposterior direction while standing. Our findings highlight the importance of task-oriented and motor learning principles while using the EMGBFB as an adjunct therapy in stroke rehabilitation. This trial was registered with trial registration number NCT01962662.

Gait bradykinesia and hypometria decrease as arm swing frequency and amplitude increase

People with Parkinson's disease (PD) have decreased arm swing movements during walking, which can be related to PD motor signs and symptoms. In this context, the aim of this study was to determine the effects of an increased arm swing frequency or amplitude on the gait parameters in people with PD and healthy older adults. Seventeen individuals with PD and 19 older people were invited to walk on a 10 m pathway under three experimental conditions: (i) usual walking (no arm swing instructions); (ii) an increased arm swing amplitude; and (iii) an increased arm swing frequency. Both groups had an increased stride speed, vertical center of mass and arm swing accelerations and decreased double support time under the increased arm swing amplitude and frequency conditions. People with PD were able to modulate the gait parameters according to the experimental conditions, but at a smaller magnitude than the older individuals. These results indicate that bradykinesia and hypometria of gait can be positively overcome by increasing the amplitude and frequency of arm swing. Arm movements should be included in gait rehabilitation protocols for PD.

Comparison of motor skill learning, grip strength and memory recall on land and in chest-deep water

Immersion in chest-deep water may augment explicit memory in healthy adults however, there is limited information on how this environment might affect implicit memory or motor learning. The purpose of this study was to compare the speed and accuracy for learning a motor skill on land and in chest-deep water. Verbal word recall and grip strength were included to gain a more complete understanding of the intervention. Sixty-two younger adults (age = 23.3 ± 3.59 yrs.) were randomly assigned to either a water group immersed to the xiphoid or a land group. Participants in both groups completed the same eight practice trials of a mirror-drawing task on two separate days. Outcome measures for this task included time and error numbers to complete each drawing. The number of words recalled using a 12 word recall test, and peak grip strength using a hand dynamometer were measured each day of testing. The influence of environment and repeated practice on each outcome measure were assessed with an analysis of variance and effect sizes (ES). Time and errors for both groups significantly decreased with practice (p < 0.01, ES = 0.11-0.28), however the drawing time was greater in water than on land for trials 1, 5, and 6 (ES = 0.50-0.55). There was a 7% increase in words recalled (9.24 ± 1.19 vs 8.60 ± 1.19) and a 16% increase in grip strength (405 ± 104 vs 342 ± 83) for water than land groups (ES 0.54-0.64). Healthy adults in chest-deep water and on land display comparable mirror-drawing speed and accuracy after minimal practice. Curiously, water immersion may augment verbal word recall and grip strength abilities.

The effect of transcranial direct current stimulation (tDCS) on locomotion and balance in patients with chronic stroke: study protocol for a randomised controlled trial

BACKGROUND

Following stroke, patients are often left with hemiparesis that reduces balance and gait capacity. A recent, non-invasive technique, transcranial direct current stimulation, can be used to modify cortical excitability when used in an anodal configuration. It also increases the excitability of spinal neuronal circuits involved in movement in healthy subjects. Many studies in patients with stroke have shown that this technique can improve motor, sensory and cognitive function. For example, anodal tDCS has been shown to improve motor performance of the lower limbs in patients with stroke, such as voluntary quadriceps strength, toe-pinch force and reaction time. Nevertheless, studies of motor function have been limited to simple tasks. Surprisingly, the effects of tDCS on the locomotion and balance of patients with chronic stroke have never been evaluated. In this study, we hypothesise that anodal tDCS will improve balance and gait parameters in patients with chronic stroke-related hemiparesis through its effects at cortical and spinal level.

METHODS/DESIGN

This is a prospective, randomised, placebo-controlled, double-blinded, single-centre, cross-over study over 36 months. Forty patients with chronic stroke will be included. Each patient will participate in three visits: an inclusion visit, and two visits during which they will all undergo either one 30-min session of transcranial direct current stimulation or one 30-min session of placebo stimulation in a randomised order. Evaluations will be carried out before, during and twice after stimulation. The primary outcome is the variability of the displacement of the centre of mass during gait and a static-balance task. Secondary outcomes include clinical and functional measures before and after stimulation. A three-dimensional gait analysis, and evaluation of static balance on a force platform will be also conducted before, during and after stimulation.

DISCUSSION

These results should constitute a useful database to determine the aspects of complex motor function that are the most improved by transcranial direct current stimulation in patients with hemiparesis. It is the first essential step towards validating this technique as a treatment, coupled with task-oriented training.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02134158 . First received on 18 December 2013; last updated on 14 September 2016. Other study ID numbers: P120135 / AOM12126, 2013-A00952-43.

Validation of simplified centre of mass models during gait in individuals with chronic stroke

BACKGROUND

The feasibility of using a multiple segment (full-body) kinematic model in clinical gait assessment is difficult when considering obstacles such as time and cost constraints. While simplified gait models have been explored in healthy individuals, no such work to date has been conducted in a stroke population. The aim of this study was to quantify the errors of simplified kinematic models for chronic stroke gait assessment.

METHODS

Sixteen individuals with chronic stroke (>6months), outfitted with full body kinematic markers, performed a series of gait trials. Three centre of mass models were computed: (i) 13-segment whole-body model, (ii) 3 segment head-trunk-pelvis model, and (iii) 1 segment pelvis model. Root mean squared error differences were compared between models, along with correlations to measures of stroke severity.

FINDINGS

Error differences revealed that, while both models were similar in the mediolateral direction, the head-trunk-pelvis model had less error in the anteroposterior direction and the pelvis model had less error in the vertical direction. There was some evidence that the head-trunk-pelvis model error is influenced in the mediolateral direction for individuals with more severe strokes, as a few significant correlations were observed between the head-trunk-pelvis model and measures of stroke severity.

INTERPRETATION

These findings demonstrate the utility and robustness of the pelvis model for clinical gait assessment in individuals with chronic stroke. Low error in the mediolateral and vertical directions is especially important when considering potential stability analyses during gait for this population, as lateral stability has been previously linked to fall risk.

The effects of Pilates exercise on cardiopulmonary function in the chronic stroke patients: a randomized controlled trials

[Purpose] The purpose of this study was to examine the effect of modified Pilates exercise on cardiopulmonary function in chronic stroke patients. [Subjects and Methods] Twenty participants (age, 62.7 ± 7.3 years; height, 163.3 ± 8.5 cm; weight, 68.8 ± 10.3 kg) were recruited for this study, and randomly allocated to the modified Pilates exercise group (n=10) or the control group (n=10). Graded submaximal treadmill exercise test was used to examine the status of patients' cardiopulmonary function, based on maximal oxygen intake, at the end of a patient's exercise tolerance limit. [Results] The resting heart rates, maximal oxygen intake, and maximal oxygen intake per kilogram were significantly different after 8 weeks of modified Pilates exercise. In addition, these variables were also significantly different between the Pilates and control groups after 8 weeks. [Conclusion] This study has demonstrated that 8 weeks of modified Pilates exercise program can have a positive influence on patients with chronic stroke, potentially by enhancing the cardiopulmonary function, which may have positive implications for increasing their functional ability.

Comparison of gait symmetry between poststroke fallers and nonfallers during level walking using triaxial accelerometry: A STROBE-compliant cross-sectional study

To compare the degree of gait symmetry of chronic poststroke fallers with that of nonfallers during level walking using triaxial accelerometry.In this cross-sectional study, a total of 14 patients with chronic stroke were recruited from a community hospital from February 2015 to July 2016. Patient characteristics, including the number of falls in the previous 12 months, were obtained from medical records. The Berg Balance Scale (BBS) and timed up and go (TUG) test were used at the onset of the study. Triaxial accelerometers were attached to the back and bilateral lower extremities of each subject with sampling rates of 120 Hz. The cross-correlation between the acceleration signals of the affected and unaffected feet was measured to assess the degree of gait symmetry. The triaxial acceleration signals of the 5 consecutive and bilateral strides from the middle of each trial were processed to measure the cross-correlation and time delay (Ts) between the magnitude of the acceleration vector of the affected and unaffected foot.After controlling for possible confounding factors, the mixed-effect models showed that cross-correlation was significantly higher among nonfallers than fallers (β = -0.093; standard error [SE] = 0.029; P-value = 0.002), and that the Ts was significantly longer among fallers than nonfallers (β = -1.900; SE = 0.719; P-value = 0.011).Cross-correlation and Ts between the affected and unaffected lower extremities may be useful indicators to distinguish poststroke fallers from nonfallers.

A systematic review of mechanisms of gait speed change post-stroke. Part 2: exercise capacity, muscle activation, kinetics, and kinematics

BACKGROUND

Regaining locomotor ability is a primary goal in stroke rehabilitation and is most commonly measured using changes in self-selected walking speed. However, walking speed cannot identify the mechanisms by which an individual recovers. Laboratory-based mechanistic measures such as exercise capacity, muscle activation, force production, and movement analysis variables may better explain neurologic recovery.

OBJECTIVES

The objectives of this systematic review are to examine changes in mechanistic gait outcomes and describe motor recovery as quantified by changes in laboratory-based mechanistic variables in rehabilitation trials.

METHODS

Following a systematic literature search (in PubMed, Ovid, and CINAHL), we included rehabilitation trials with a statistically significant change in self-selected walking speed post-intervention that concurrently collected mechanistic variables. Methodological quality was assessed using Cochrane Collaboration's tool. Walking speed changes, mechanistic variables, and intervention data were extracted.

RESULTS

Twenty-five studies met the inclusion criteria and examined: cardiorespiratory function (n = 5), muscle activation (n = 5), force production (n = 11), and movement analysis (n = 10). Interventions included: aerobic training, functional electrical stimulation, multidimensional rehabilitation, robotics, sensory stimulation training, strength/resistance training, task-specific locomotor rehabilitation, and visually-guided training.

CONCLUSIONS

Following this review, no set of outcome measures to mechanistically explain changes observed in walking speed were identified. Nor is there a theoretical basis to drive the complicated selection of outcome measures, as many of these outcomes are not independent of walking speed. Since rehabilitation literature is yet to support a causal, mechanistic link for functional gains post-stroke, a systematic, multimodal approach to stroke rehabilitation will be necessary in doing so.

Pilot study of effective methods for measuring and stretching for pectoral muscle tightness in breast cancer patients

[Purpose] To evaluate differences in pectoral muscle tightness according to arm abduction angle and to determine the best arm abduction angle for stretching of pectoral muscle tightness in breast cancer patients. [Subjects and Methods] Horizontal abduction differences of shoulders were measured bilaterally by arm abduction to 45°, 90°, and 135° to determine the best arm abduction angle for measuring pectoral muscle tightness. Thirty-two patients were divided into three pectoral muscle stretching groups (A: 45°, B: 90°, and C: 135°). We measured the shoulder range of motion, scores of the Disabilities of the Arm, Shoulder, and Hand, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire and the Breast Module, and pain levels (using a visual analog scale) before and after therapy. [Results] The differences in degree of horizontal abduction between shoulders were significantly larger for arm abduction to 90° and 135° than that to 45°. Groups B and C showed greater improvements in horizontal abduction limitations than group A. [Conclusion] Horizontal abduction differences between shoulders are prominent when arms are abducted to 90° and 135°. The appropriate arm abduction angle for measuring horizontal abduction and effective stretching of pectoral muscle tightness may be >90°.

Identifying candidates for targeted gait rehabilitation after stroke: better prediction through biomechanics-informed characterization

BACKGROUND

Walking speed has been used to predict the efficacy of gait training; however, poststroke motor impairments are heterogeneous and different biomechanical strategies may underlie the same walking speed. Identifying which individuals will respond best to a particular gait rehabilitation program using walking speed alone may thus be limited. The objective of this study was to determine if, beyond walking speed, participants' baseline ability to generate propulsive force from their paretic limbs (paretic propulsion) influences the improvements in walking speed resulting from a paretic propulsion-targeting gait intervention.

METHODS

Twenty seven participants >6 months poststroke underwent a 12-week locomotor training program designed to target deficits in paretic propulsion through the combination of fast walking with functional electrical stimulation to the paretic ankle musculature (FastFES). The relationship between participants' baseline usual walking speed (UWS_baseline), maximum walking speed (MWS_baseline), and paretic propulsion (prop_baseline) versus improvements in usual walking speed (∆UWS) and maximum walking speed (∆MWS) were evaluated in moderated regression models.

RESULTS

UWS_baseline and MWS_baseline were, respectively, poor predictors of ΔUWS (R ²  = 0.24) and ΔMWS (R ²  = 0.01). Paretic propulsion × walking speed interactions (UWS_baseline × prop_baseline and MWS_baseline × prop_baseline) were observed in each regression model (R ² s = 0.61 and 0.49 for ∆UWS and ∆MWS, respectively), revealing that slower individuals with higher utilization of the paretic limb for forward propulsion responded best to FastFES training and were the most likely to achieve clinically important differences.

CONCLUSIONS

Characterizing participants based on both their walking speed and ability to generate paretic propulsion is a markedly better approach to predicting walking recovery following targeted gait rehabilitation than using walking speed alone.

Measurement Error in Functional Balance and Mobility Tests for People With Stroke: What Are the Sources of Error and What Is the Best Way to Minimize Error?

Objective. To assess the degree and source of measurement error in functional balance and mobility tests for people with stroke, and to identify the most effective method of data collection to minimize error.

Design. To assess the degree and source of error, the total, systematic, and random error were calculated for within-session, test-retest, and interrater testing. To identify the most effective method of data collection, the total error was calculated for 4 data collection methods: 1 familiarization trial, then scoring a 2nd trial; 2 familiarization trials, then scoring a 3rd trial; averaging 2 trials, then averaging 3 trials.

Setting. Stroke services in National Health Service hospitals.

Patients. Thirty-five people with a poststroke hemiplegia.

Interventions. None.

Main Outcome Measures. Five tests provided interval-level data: arm raise (sitting and standing), weight shift, tap, and step-up. Four tests provided ratio-level data: forward reach (sitting and standing) and 5-m timed walk (with and without an aid).

Results. Total measurement error ranged from zero for the step-up test to 55% for within-session error for the 5-m walk without an aid. Ratio data tests showed somewhat greater error than interval data tests (5%-55% vs. 0%-46%). A within-session practice effect for the standing forward reach, 5-m walk (with and without an aid), and weight shift tests was found. For the other tests, random error was greater than the systematic error. Interrater testing had the least error. For most tests, the average of 2 trials produced the least measurement error. For the 5-m walk, the mean obtained from 2 or 3 trials was equally effective. For the step-up test, the mean of 3 trials was slightly more effective. The overall error from all 3 sources was 3 lifts for sitting arm raise, 11 cm for sitting forward reach, 3 lifts for the standing arm raise, 7.5 cm for standing forward reach, 4.5 s for walking with an aid, 3 shifts on the weight shift test, 1.1 s for walking without an aid, 2 taps, and 1 step up.

Conclusion. The tests using interval data showed less error than ratio-data tests and may be preferable measurement tools. Taking an average of 2 trials was the most accurate data collection method.

Knee loading patterns of the non-paretic and paretic legs during post-stroke gait

BACKGROUND

Post-stoke gait disorders could cause secondary musculoskeletal complications associated with excessive repetitive loading. The study objectives were to 1) determine the feasibility of measuring common proxies for dynamic medial knee joint loading during gait post-stroke with external knee adduction (KAM) and flexion moments (KFM) and 2) characterize knee loading and typical load-reducing compensations post-stroke.

METHODS

Participants with stroke (n=9) and healthy individuals (n=17) underwent 3D gait analysis. The stroke and healthy groups were compared with unpaired t-tests on peak KAM and peak KFM and on typical medial knee joint load-reducing compensations; toe out and trunk lean. The relationship between KAM and load-reducing compensations in the stroke group were investigated with Spearman correlations.

RESULTS

Mean (SD) values for KAM and KFM in the healthy group[KAM=2.20 (0.88)%BW*ht; KFM=0.64 (0.60)%BW*ht] were not significantly different from the values for the paretic [KAM=2.64 (0.98)%BW*ht; KFM=1.26 (1.13)%BW*ht] or non-paretic leg of the stroke group[KAM=2.23(0.62)%BW*ht; KFM=1.10 (1.20)%BW*ht]. Post hoc one sample t-tests revealed greater loading in stroke participants on the paretic (n=3), non-paretic (n=1) and both legs (n=2) compared to the healthy group. The angle of trunk lean and the angle of toe out were not related to KAM in the stroke group.

DISCUSSION

Measurement of limb loading during a gait post-stroke is feasible and revealed excessive loading in individuals with mild to moderate stroke compared to healthy adults. Further investigation of potential joint degeneration and pain due to repetitive excessive loading associated with post-stroke gait is warranted.

Quantifying Change During Outpatient Stroke Rehabilitation: A Retrospective Regression Analysis

OBJECTIVE

To examine change and individual trajectories for balance, upper extremity motor capacity, and mobility in people poststroke during the time they received outpatient therapies.

DESIGN

Retrospective analyses of an observational cohort using hierarchical linear modeling.

SETTING

Outpatient rehabilitation.

PARTICIPANTS

Persons poststroke (N=366).

INTERVENTIONS

Usual outpatient physical and occupational therapy.

MAIN OUTCOMES MEASURES

Berg Balance Scale (BBS), Action Research Arm Test (ARAT), and walking speed were used to assess the 3 domains. Initial scores at the start of outpatient therapy (intercepts), rate of change during outpatient therapy (slopes), and covariance between slopes and intercepts were modeled as random effects. Additional variables modeled as fixed effects were duration (months of outpatient therapy), time (days poststroke), age (y), and inpatient status (if the patient went to an inpatient rehabilitation facility [IRF]).

RESULTS

A patient with average age and time started at 37 points on the BBS with a change of 1.8 points per month, at 35 points on the ARAT with a change of 2 points per month, and with a walking speed of .59m/s with a change of .09m/s per month. When controlling for other variables, patients started with lower scores on the BBS and ARAT or had slower walking speeds at admission if they started outpatient therapy later than average or went to an IRF.

CONCLUSIONS

Patients generally improved over the course of outpatient therapy, but there was considerable variability in individual trajectories. Average rates of change across all 3 domains were small.