The relationship between gait asymmetry and stability in people with sub-acute stroke.

Individuals with Parkinson's disease (PD) often manifest significant temporal and spatial asymmetries of the lower extremities during gait, which significantly contribute to mobility impairments. While the neural mechanisms underlying mobility asymmetries within this population remain poorly understood, recent evidence points to altered microstructural integrity of white matter fiber tracts within the corpus callosum as potentially playing a substantial role. The purpose of this study was to quantify spatial and temporal gait asymmetries as well as transcallosal microstructural integrity of white matter fiber tracts connecting the primary and secondary sensorimotor cortices in people with PD and age-matched control participants. Spatial and temporal gait asymmetry in the levodopa off state was assessed using an instrumented walkway. On the next day, diffusion-weighted images were collected to assess white matter microstructural integrity in transcallosal fibers connecting the homologous sensorimotor cortical regions. People with PD exhibited significantly more temporal and spatial gait asymmetry than healthy control subjects. Furthermore, people with PD had significantly reduced white matter microstructural integrity of transcallosal fibers connecting homologous regions of the pre-supplementary motor and supplementary motor areas (SMAs), but not the primary motor or somatosensory cortices. Finally, reduced transcallosal fiber tract integrity of the pre-SMA and S1 was associated with greater step length asymmetry in people with PD. People with PD showed increased step length asymmetries and decreased microstructural integrity of callosal white matter tracts connecting the higher-order sensorimotor cortices (pre-SMA and SMA). The strong association between gait asymmetries and corpus collosum integrity, supports the hypothesis that reduced transcallosal structural connectivity is a significant mechanism underlying gait asymmetries in people with PD.

Analysis of impairments influencing gait velocity and asymmetry of hemiplegic patients after mild to moderate stroke

Children with hemiplegic cerebral palsy (hemi-CP) frequently experience deficits in dynamic balance, a crucial factor influencing gait function. This imbalance can manifest as temporal–spatial gait asymmetry, where movement patterns differ between the affected and less affected sides. This study investigated how temporal–spatial gait asymmetries and dynamic balance are associated in children with hemi-CP. Eighty-five children with hemi-CP (age: 13.27 ± 1.72 years) were included. The temporal (AITemporal) and spatial (AISpatial) gait asymmetry indices were, respectively, computed with reference to the swing time and step length of affected and less affected sides, which were collected through a 3D gait analysis. Measures of dynamic balance included the directional dynamic limit-of-stability (D-LOSdirectional) assessed across multiple directions (forward, rearward, affected, and less affected) and the overall dynamic limit-of-stability (D-LOSoverall) during static stance, in addition to the heel-to-heel base of support (BOSH-to-H) during walking, the dynamic gait index (DynGI), and the Timed Up and Down Stair (TUDS) test.The D-LOSoverall correlated negatively with the temporal (r = −0.437, p < 0.001) and spatial (r = −0.279, p = 0.009) asymmetries. The D-LOSdirectional (forward, rearward, affected, and less affected) correlated negatively with temporal asymmetry (r ranged from −0.219 to −0.411, all p < 0.05), but only the D-LOSdirectional rearward (r = −0.325, p = 0.002) and less affected (r = −0.216, p = 0.046) correlated with spatial asymmetry. The BOSH-to-H correlated positively with both temporal (r = 0.694, p < 0.001) and spatial (r = 0.503, p < 0.001) asymmetries. The variation in D-LOSoverall and BOSH-to-H accounted for 19.1% and 48.2%, respectively, of the variations in the temporal asymmetry and 7.8% and 25.3% of the variations in the spatial asymmetry. The findings of this study suggest that dynamic balance control is related to the magnitude of temporal–spatial gait asymmetries in children with hemi-CP. This evidence lays the groundwork for further research into the mechanism linking gait asymmetry and dynamic balance, potentially leading to a deeper understanding of these impairments, while also highlighting the need for longitudinal studies with the inclusion of a broader population to enhance the generalizability of the findings.

Associations between the site of brain injury and poststroke gait impairment are poorly understood. Temporal gait asymmetry after stroke is a salient index of gait dysfunction that has important functional consequences. The current study investigated whether subtraction lesion analysis could distinguish brain regions associated with persisting temporal gait asymmetry in chronic stroke patients. Analysis was conducted on 37 chronic ambulatory stroke patients (17 symmetrical gait, 20 asymmetrical gait). Spatiotemporal gait parameters were recorded using an instrumented walking surface. Lesions were traced from 3D T1-MRI, and region of interest images were generated. The lesion overlay of patients with symmetrical gait was subtracted from patients with asymmetrical gait to highlight voxels more frequently lesioned in asymmetrical patients and relatively spared in symmetrical patients. Demographic data were comparable between the 2 groups. Asymmetrical patients exhibited significantly higher National Institute of Health Stroke Scale neglect scores and more severe motor impairment. Gait asymmetry was significantly correlated to Chedoke-McMaster Stroke Scale leg (r=-0.767, P<0.001) and foot (r=-0.759, P<0.001) scores, whereas gait speed correlated less strongly. After subtraction analysis, injury to the posterolateral putamen was evident 60% to 80% more frequently in the asymmetrical group compared to the symmetrical group. In this sample of ambulatory chronic stroke patients, damage to the posterolateral putamen was associated with temporal gait asymmetry. Further advances in our understanding of the neural correlates of gait asymmetry may provide prognostic markers for future persistent gait dysfunction and lead to early targeted rehabilitation when key regions are damaged.

More than 50,000 new cases of ankle arthritis are being reported annually. Total ankle arthroplasty (TAA) is increasing in popularity as the treatment for end-stage disease with the goal of decreasing pain and improving function. Decreased walking speed is often associated with decreased function. Following TAA gait asymmetry is prevalent and often associated with impaired function. PURPOSE: Determine if kinematic and kinetic asymmetries are predictors of walking speed following TAA. METHODS: Three-dimensional motion capture was used to collect bilateral kinematic and kinetic data during 7 walking trials at a self-selected speed on 34 patients 5 years following TAA. Patients were excluded from this analysis if they had any complications requiring additional surgical intervention or were unable to walk without the use of an assistive device. Discrete ankle kinematic and kinetic variables as well as ground reaction forces (GRF) were extracted from ensemble curves for analysis. A linear regression model was used to identify significant predictors of walking speed based on gait asymmetries. Variables were removed from the model if they did not provide a statistically significant improvement to the model (p<0.05). Finally, individual limbs as well as symmetry measures were included in one regression model to determine the interaction between the asymmetry and individual limb measures. RESULTS: Asymmetries in the anterior GRF, peak dorsiflexion angle and the weight acceptance vertical GRF were able to explain 32.5% of the variance (P=0.008) in walking speed. The addition of the independent limb measures explained an additional 54% of the variance in walking speed. A model that combined peak plantarflexion moment and propulsion vertical GRF asymmetries in combination with the surgical side peak plantarflexion moment and the non-surgical weight acceptance vertical GRF explained 86.5% of the variance in walking speed (p<0.001). CONCLUSIONS: Asymmetries in movement patterns predicts post-TAA walking speed, however, the addition of individual limb mechanics more than doubles the explained variance. These results suggest that rehabilitation programs in the post-TAA patient aimed at improving function should target the restoration of symmetrical gait mechanics in addition to targeting surgical side propulsion.

Relationship between asymmetry of quiet standing balance control and walking post-stroke

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

Background and Objectives Temporal gait asymmetry (TGA) affects 55% of people with stroke. This study investigated the effects of augmented feedback during overground gait training, on TGA. Methods Eighteen people with chronic stroke were randomized to receive one of two feedback displays (A or B) and one of three feedback frequencies; no feedback (0%), after alternate walking trials (50%) or after every trial (100%). Display A depicted the TGA ratio as a vertical line along a horizontal axis with perfect symmetry in the middle. Display B depicted single limb stance duration of each leg as a bar graph. Participants completed 25 repetitions of 30 second trials with their assigned feedback (acquisition). Participants completed 10 repetitions of 30 second trials without feedback 24 hours later (retention). A pressure sensitive mat recorded TGA and speed. Changes in TGA and speed were investigated by plotting individual motor learning curves and fitting a curve with locally estimated scatterplot smoothing (LOESS) for each feedback group. An effect of feedback was defined a priori as a LOESS fitted curve with a decreasing slope from acquisition to retention. Results LOESS curve exhibited a decreasing slope for TGA in the 100B group only and for speed in the 50A and 0FB groups. Discussion This study provides preliminary evidence that visual feedback delivered at a high frequency during a single session of overground walking can change TGA post-stroke without reducing gait speed. An overground gait intervention with high frequency visual feedback to improve TGA post-stroke is worthwhile to investigate.

This study investigated the 3-axis gait kinematics of people with stroke to healthy individuals. The specific focus was stroke effects on shank movements in the sagittal, frontal and transverse planes. Sixteen stroke patients and sixteen healthy participants walked along a 10-meter walkway at self-comfortable walking speed, with shank angular velocity measured using two gyroscopes integrated into an Inertial Measurement Unit (IMU). Gait events in all motion planes, temporal gait parameters, kinematic data, asymmetry indexes (ASI), and Bland-Altman correlations were also computed. Greater diversity gait patterns were observed in stroke patients. Compared with healthy controls, stroke patients showed reduced stance time on their affected side and lower non-affected swing time, causing gait asymmetry, as reflected in higher ASIs. The stroke patients’ shank exhibited limited motion in all motion planes resulting in lower angular velocity and displacement. Sagittal plane angular velocity results were validated using intra-subject comparisons that showed good agreement between limbs in healthy subjects. These empirical findings in this study provide evidence that shank-based IMUs are effective in revealing temporal-spatial gait alterations in people with stroke compared to healthy individuals which can be exploited to develop a targeted rehabilitation plan to reduce abnormalities in the stroke patient group.

ABSRACT. Human gait is inherently rhythmical, thus walking to rhythmic auditory stimulation is a promising intervention to improve temporal gait asymmetry (TGA) following neurologic injury such as stroke. However, the degree of benefit may relate to an individual’s underlying rhythmic ability. We conducted an initial investigation into the relationship between rhythm abilities and responsiveness of TGA when walking to a metronome. TGA was induced in neurotypical young adults with ankle and thigh cuff weights. Participants were grouped by strong or weak rhythm ability based on beat perception and production tests. TGA was induced using a unilateral load affixed to the non-dominant leg. Participants walked under three conditions: uncued baseline, metronome set to 100% of baseline cadence, and metronome set to 90% of baseline cadence. Repeated measures analysis using generalized estimating equations was conducted to determine how rhythm ability affected TGA response in each walking condition. Most participants improved TGA when walking to a metronome at either tempo compared to baseline; however, this improvement did not differ between strong and weak rhythm ability groups. Those who scored worse on the rhythm perception test also were poorer at synchronizing their steps to the beat. The induced TGA is smaller than what is commonly experienced after stroke. A larger induced TGA may be necessary to reveal subtle differences in responsiveness to rhythmical auditory stimulation between those with strong and weak rhythm abilities.

We investigated postural stability through the margin of stability (MoS) while reaching and grasping an object with increasing difficulty levels in younger, fallers and non-fallers. Forty-five individuals distributed into three groups participated in this study: younger adults (YA), non-fallers (OA), and fallers (FOA). They stood upright and reached and grasped a dowel. Six conditions combining the stability of the dowel’s base and obstacles close to the dowel were manipulated to characterize different difficulty levels. We computed the MoS in both anterior-posterior (AP) and medial-lateral (ML) directions in the interval between reaching onset and dowel contact. From the MoS time series, we analyzed the minimum and maximum, including the time of occurrence of these events. The MoS was smaller for OA than for YA in both directions. In the ML direction, the minimum MoS was smaller for FOA than for YA. The minimum MoS took place earlier for FOA than YA in the AP direction. FOA and OA exhibited similar behavior with reduced MoS, suggesting impaired postural control during reaching-to-grasping in a standing posture. FOA used a more cautious strategy by reverting the MoS earlier than YA, allowing them to increase their MoS before YA when preparing to grasp the dowel.

Gait asymmetry, characterized by spatial (e.g., step length) and temporal (e.g., swing time) differences between the paretic and non-paretic limbs, is common after stroke. Despite increasing research on gait asymmetry, its associations with stroke-related factors remain unclear. This systematic review and meta-analysis aimed to investigate these associations and provide insights for post-stroke rehabilitation. A comprehensive search of PubMed, MEDLINE, CINAHL, and Scopus identified observational studies published between January 2000 and June 2024. Studies examining the relationship between stroke-related factors and post-stroke gait asymmetry were included. Meta-analyses were performed on factors with sufficient data, extracting correlation coefficients (r) to estimate effect sizes. Fourteen studies met inclusion criteria, with eight studies (n = 468 participants) included in meta-analyses. Temporal asymmetry was significantly associated with lower limb motor and sensory deficits (r = -0.73; 95 % CI: -0.88 to -0.57; p < 0.01), leg strength (r = -0.50; 95 % CI: -0.64 to -0.36; p < 0.01), spasticity (r = 0.51; 95 % CI: 0.31-0.72; p < 0.01), and overall motor performance (r = -0.68; 95 % CI: -0.74 to -0.61; p < 0.01). Spatial asymmetry was significantly associated with leg strength (r = -0.31; 95 % CI: -0.45 to -0.17; p < 0.01), spasticity (r = 0.67; 95 % CI: 0.49-0.85; p < 0.01), and overall lower limb impairments (r = -0.44; 95 % CI: -0.64 to -0.23; p < 0.01). Lower limb motor and sensory deficits, along with overall motor performance, were the factors most strongly associated with temporal asymmetry. Spasticity and/or contracture was the factor most strongly associated with spatial asymmetry. These findings highlight the need to assess and manage gait asymmetry separately in post-stroke rehabilitation.

Rhythm Perception and Production Abilities and Their Relationship to Gait After Stroke

Gait asymmetry is common after stroke and is a major risk factor for falls. In particular, temporal gait asymmetry often remains in the chronic stage of stroke. However, health insurance does not cover rehabilitation for patients with chronic stroke in many countries. Accordingly, it is undetermined whether individually supervised exercise therapy has beneficial effects on chronic hemiparetic gait. Patients with stroke (n = 25) more than 6 months after onset performed 70 min of individually supervised exercise twice weekly for 2 months in 16 sessions with qualified personnel. The intervention significantly reduced the pre-swing phase on the paretic side (mean = 91.8%, 95%CI, 84.8–98.8). In addition, there was a significant improvement in pre-swing phase symmetry in those with great asymmetry prior to the intervention (p = 0.022). Step length significantly increased after the intervention on both sides (non-paretic, p = 0.029; paretic, p = 0.0055). Walking time at both comfortable and maximum speeds was significantly shortened (comfortable, p = 0.0041; maximum, p < 0.0001). Our findings suggest that there remains scope to improve gait ability with individually supervised exercise therapy in patients with chronic stroke, whose functional recovery is often considered unlikely. This type of intervention may be a simple and effective option to improve gait parameters, including temporal asymmetry, even in patients with chronic stroke.

Falls are a major health concern after stroke. Spatial and temporal gait asymmetry and variability can contribute to instability and increased fall risk in persons with stroke (PwS). We aimed to quantify gait spatiotemporal symmetry and variability parameters in PwS undergoing rehabilitation in the subacute stage of the disease, by comparison to healthy participants, and to examine the associations between these parameters and patients' reactive and proactive balance capacity. Twenty-two PwS and 12 healthy adults walked over a computerized treadmill system at their self-selected walking speed. Symmetry and variability of gait parameters (step length, swing time, and stance time) as well as upper extremity and lower extremity angular range of motion in the sagittal plane were extracted. In addition, the Berg Balance Scale (BBS) and the fall threshold in response to sudden surface translations at increasing intensities were assessed. PwS demonstrated significantly higher asymmetry in all gait parameters in comparison to controls. Also, PwS demonstrated increased stance time variability in comparison to healthy controls and increased swing time variability in the paretic lower extremity. Significant negative associations were found between fall threshold and stance time asymmetry in PwS (r = -0.48, P = 0.022), between the BBS and swing time asymmetry (r = -0.50, P = 0.018), and between the BBS and stance time variability of the paretic lower extremity (r = -0.56, P = 0.006). Findings highlight the importance of gait temporal symmetry and variability measures for dynamic balance control after stroke. These parameters should be considered when assessing gait recovery and safety in PwS.Video Abstract available for more insight from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A355).