Gait Variability Research Articles

Poincaré analysis detects pathological limb loading rate variability in post-anterior cruciate ligament reconstruction individuals

BackgroundPost-ACLR individuals can experience repeated exposure to variable limb loading, which contributes to development of knee osteoarthritis. Variable limb loading can present as loading rate variability (LRV) and is magnified during tasks like fast walking when the system is stressed. Nonlinear measures that evaluate temporal variability have successfully detected changes in gait variability associated with altered motor control, however, appropriately describing and uncovering the nature of gait variability has been challenging. Here, Poincaré analysis, a nonlinear method unique in its ability to capture different aspects of variability, served to uncover and quantify changes in limb LRV. It was hypothesized that post-ACLR individuals’ overloaded limbs would quantitatively and graphically demonstrate greater short-term stride-to-stride and long-term limb LRV during fast walking compared to the underloaded and healthy control limbs. MethodsFourteen post-ACLR individuals and fourteen healthy controls completed a walking protocol on an instrumented treadmill where they walked at 1.0 m/s and 1.5 m/s for 5-minutes each. A Welch’s test was performed to compare differences in short-term and long-term LRV metrics for the post-ACLR individuals’ overloaded and underloaded limbs and the healthy controls’ right limbs. ResultsAnalyses revealed that the post-ACLR individuals’ overloaded limb exhibited significantly greater short-term and long-term values compared to the underloaded and healthy control limbs at 1.5 m/s (p<0.05). Additionally, the loading rate data was widely scattered across the plots for the overloaded limb, indicating greater LRV. SignificancePoincaré analysis successfully identified that post-ACLR overloaded limbs exhibited impaired motor control during fast walking based on quantitative and graphical changes in variability. This highlights the clinical applications of Poincaré analysis, with the plots potentially serving as an easy-to-interpret diagnostic tool for pathological limb LRV.

Motion planning and control of planar serial chain articulating locomotion system

This paper addresses two important problems in motion planning and control of serial chain planar articulating locomotion systems moving on a flat surface. Locomotion systems generally use closed curve cyclic gaits to perform maneuvers in the environment. The geometric mechanics tools are used to identify the cyclic gaits. Firstly, a motion control approach is presented using a single cyclic gait parametrized with variable gait parameters. The parameterized gait is used to drive the system along a continuous trajectory with varying curvature. On the other hand, the proposed approach presents how the gait parameters can be controlled to smoothly track a continuous trajectory. Secondly, this paper presents a joint coordination approach to generalize the height function based approach to design cyclic gaits for the system having joint space with more than two degrees of freedom. Using joint coordination approach, cyclic gaits can be designed for different motion behaviors such as longitudinal motion, sideways motion and rotation in place. The joint coordination approach also helps generalizing the proposed motion control approach to planar serial chain articulating robots with any even number of joints.

Ground reaction force analysis in flexible and rigid flatfoot subjects

BackgroundFlatfoot is a structural and functional deformity of the foot that might change ground reaction force variables of gait. Evaluating the components of ground reaction force in three dimensions during gait is considered clinically important. This study aimed to investigate the components of ground reaction force, impulse, and loading rate during gait in people with flexible and rigid flatfoot compared to healthy subjects. 20 young women with flatfoot in two experimental groups (10 with rigid flatfoot and 10 with flexible flatfoot) and 10 healthy women in the control group participated in this study. Ground reaction force components during gait were measured using two force plates. The peak of ground reaction forces, impulse, and loading rate were then extracted. Data were processed and analyzed using MATLAB and SPSS software. One-way ANOVA with a significant level (P˂0.05) was used for statistical analysis. The results showed that peak braking force was higher in the rigid flatfoot group than in the control group (p = 0.016) and the flexible flatfoot group (p = 0.003). The posterior force loading rate was significantly higher in the rigid flatfoot group than in the flexible flatfoot group (P = 0.04). There was no significant difference in vertical loading rate between groups (P˃0.05). Since the maximal posterior ground reaction force was higher in the subjects with rigid flatfoot than in those with flexible flatfoot and healthy subjects, the increase in posterior ground reaction force is associated with an increase in anterior shear force at the knee.

Does hearing impairment affect gait under realistic conditions?

Hearing loss is associated with increased risk of falling, but little is known about how hearing impairment might affect mobility. Here, we report preliminary results from an ongoing experimental study investigating dynamic properties of gait while walking with and without impaired hearing. Young- and middle-aged adult participants with self-reported normal hearing completed four walking tasks, 2 indoors, 2 outdoors, each conducted with and without a simulated hearing loss. In the impaired condition, participants wore an insert earplug in one ear combined with binaural, circumaural noise-damping headphones. We quantified gait parameters using data from inertial measurement units (IMUs) affixed to participants’ ankles and waist, allowing participants to walk farther than in typical gait assessments. Parameters included standard gait metrics, such as limb acceleration as well as a novel spatiotemporal index quantifying variability in step patterns. Data have been collected from 13 of 30 projected participants. Analysis will focus on how temporal-spatial gait parameters and variability differ between indoor and outdoor walking with and without hearing impairment. We expect gait parameters to reflect a more variable and potentially less mobile walking strategy in the outdoor condition and with impaired hearing due to increased cognitive load and/or reduced spatial awareness in those conditions.

Dual-task turn velocity - a novel digital biomarker for mild cognitive impairment and dementia.

Disorders associated with cognitive impairment impose a significant burden on both families and society. Previous studies have indicated that gait characteristics under dual-task as reliable markers of early cognitive impairment. Therefore, digital gait detection has great potential for future cognitive screening. However, research on digital biomarkers based on smart devices to identify cognitive impairment remains limited. The aim of this study is to explore digital gait biomarkers by utilizing intelligent wearable devices for discriminating mild cognitive impairment and dementia. This study included 122 subjects (age: 74.7 ± 7.7 years) diagnosed with normal cognition (NC, n = 38), mild cognitive impairment (MCI, n = 42), or dementia (n = 42). All subjects underwent comprehensive neuropsychological assessments and cranial Magnetic Resonance Imaging (MRI). Gait parameters were collected using validated wearable devices in both single-task and dual-task (DT). We analyzed the ability of gait variables to predict MCI and dementia, and examined the correlations between specific DT-gait parameters and sub-cognitive functions as well as hippocampal atrophy. Our results demonstrated that dual-task could significantly improve the ability to predict cognitive impairment based on gait parameters such as gait speed (GS) and stride length (SL). Additionally, we discovered that turn velocity (TV and DT-TV) can be a valuable novel digital marker for predicting MCI and dementia, for identifying MCI (DT-TV: AUC = 0.801, sensitivity 0.738, specificity 0.842), and dementia (DT-TV: AUC = 0.923, sensitivity 0.857, specificity 0.842). The correlation analysis and linear regression analysis revealed a robust association between DT-TV and memory function, as well as the hippocampus atrophy. This study presents a novel finding that DT-TV could accurately identify varying degrees of cognitive impairment. DT-TV is strongly correlated with memory function and hippocampus shrinkage, suggests that it can accurately reflect changes in cognitive function. Therefore, DT-TV could serve as a novel and effective digital biomarker for discriminating cognitive impairment.

Gait patterns during overground and virtual omnidirectional treadmill walking

BackgroundOmnidirectional treadmills (ODTs) offer a promising solution to the virtual reality (VR) locomotion problem, which describes the mismatch between visual and somatosensory information and contributes to VR sickness. However, little is known about how walking on ODTs impacts the biomechanics of gait. This project aimed to compare overground and ODT walking and turning in healthy young adults.MethodsFifteen young adults completed forward walk, 180° turn, and 360° turn tasks under three conditions: (1) overground, (2) on the Infinadeck ODT in a virtual environment without a handrail, and (3) on the ODT with a handrail. Kinematic data for all walking trials were gathered using 3D optical motion capture.ResultsOverall, gait speed was slower during ODT walking than overground. When controlling for gait speed, ODT walking resulted in shorter steps and greater variability in step length. There were no significant differences in other spatiotemporal metrics between ODT and overground walking. Turning on the ODT required more steps and slower rotational speeds than overground turns. The addition of the stability handrail to the ODT resulted in decreased gait variability relative to the ODT gait without the handrail.ConclusionWalking on an ODT resembles natural gait patterns apart from slower gait speed and shorter step length. Slower walking and shorter step length are likely due to the novelty of physically navigating a virtual environment which may result in a more conservative approach to gait. Future work will evaluate how older adults and those with neurological disease respond to ODT walking.

Gait Variability and its Relationship to Functional Mobility in Hemiparetic Stroke

Background: Stroke remains a leading cause of long-term disability worldwide, with hemiplegia being one of the most common outcomes, significantly impairing gait and functional mobility. The integration of sensory stimulation techniques into rehabilitation practices offers a promising avenue for enhancing recovery outcomes in hemiplegic stroke survivors. Objective: This study aimed to investigate the effectiveness of auditory and visual sensory stimulation on improving gait parameters and functional mobility in hemiplegic stroke patients. Methods: Conducted at Mayo Hospital, Lahore, this analytical cross-sectional study involved 24 stroke survivors with hemiplegia, randomly assigned to two intervention groups. Inclusion criteria included a Modified Ashworth Scale score of 1 to 1+ and a Mini-Mental State Examination score of ≥25. One group received auditory feedback gait training (AFGT) with smart insoles, while the other engaged in sit-to-stand training with visual feedback using a Wii Balance Board, alongside conventional rehabilitation therapies. The interventions lasted four weeks, with assessments conducted pre and post-intervention. Outcome measures included the Dynamic Gait Index (DGI), Fugl-Meyer Assessment for Lower Extremity (FMA-LE), and various gait parameters. Statistical analysis was performed using SPSS version 25. Results: Post-intervention, the study observed significant improvements in DGI (mean increase: 3.5 points, p&lt;0.01), FMA-LE scores (mean increase: 10 points, p&lt;0.01), and enhanced gait parameters including step length and stride length (p&lt;0.05). The group receiving AFGT with smart insoles showed notable improvements in spatiotemporal gait parameters and balance compared to the control group, indicating the efficacy of sensory feedback in rehabilitation. Conclusion: The study demonstrates that incorporating auditory and visual feedback into rehabilitation regimens can significantly improve gait dynamics and functional mobility in hemiplegic stroke patients. These findings suggest the potential for sensory stimulation techniques to enhance the effectiveness of stroke rehabilitation, advocating for their integration into standard care practices.

Can transcranial direct current stimulation combined with interactive computerized cognitive training boost cognition and gait performance in older adults with mild cognitive impairment? a randomized controlled trial

BackgroundOlder adults with Mild Cognitive Impairment (MCI) are often subject to cognitive and gait deficits. Interactive Computerized Cognitive Training (ICCT) may improve cognitive function; however, the effect of such training on gait performance is limited. Transcranial Direct Current Stimulation (tDCS) improves cognition and gait performance. It remains unclear whether combining tDCS with ICCT produces an enhanced synergistic effect on cognition and complex gait performance relative to ICCT alone. This study aimed to compare the effects of tDCS combined with ICCT on cognition and gait performance in older adults with MCI.MethodTwenty-one older adults with MCI were randomly assigned to groups receiving either anodal tDCS and ICCT ( tDCS + ICCT ) or sham tDCS and ICCT ( sham + ICCT ). Participants played Nintendo Switch cognitive games for 40 min per session, simultaneously receiving either anodal or sham tDCS over the left dorsolateral prefrontal cortex for the first 20 min. Cognitive and gait assessments were performed before and after 15 training sessions.ResultsThe global cognition, executive function, and working-memory scores improved in both groups, but there were no significant interaction effects on cognitive outcomes. Additionally, the group × time interactions indicated that tDCS + ICCT significantly enhanced dual-task gait performance in terms of gait speed (p = 0.045), variability (p = 0.016), and dual-task cost (p = 0.039) compared to sham + ICCT.ConclusionThe combined effect of tDCS and ICCT on cognition was not superior to that of ICCT alone; however, it had a significant impact on dual-task gait performance. Administering tDCS as an adjunct to ICCT may thus provide additional benefits for older adults with MCI.Trial registrationThis trial was registered at http://www.clinicaltrials.in.th/ (TCTR 20,220,328,009).

Freezing of gait assessment with inertial measurement units and deep learning: effect of tasks, medication states, and stops

BackgroundFreezing of gait (FOG) is an episodic and highly disabling symptom of Parkinson’s Disease (PD). Traditionally, FOG assessment relies on time-consuming visual inspection of camera footage. Therefore, previous studies have proposed portable and automated solutions to annotate FOG. However, automated FOG assessment is challenging due to gait variability caused by medication effects and varying FOG-provoking tasks. Moreover, whether automated approaches can differentiate FOG from typical everyday movements, such as volitional stops, remains to be determined. To address these questions, we evaluated an automated FOG assessment model with deep learning (DL) based on inertial measurement units (IMUs). We assessed its performance trained on all standardized FOG-provoking tasks and medication states, as well as on specific tasks and medication states. Furthermore, we examined the effect of adding stopping periods on FOG detection performance.MethodsTwelve PD patients with self-reported FOG (mean age 69.33 ± 6.02 years) completed a FOG-provoking protocol, including timed-up-and-go and 360-degree turning-in-place tasks in On/Off dopaminergic medication states with/without volitional stopping. IMUs were attached to the pelvis and both sides of the tibia and talus. A temporal convolutional network (TCN) was used to detect FOG episodes. FOG severity was quantified by the percentage of time frozen (%TF) and the number of freezing episodes (#FOG). The agreement between the model-generated outcomes and the gold standard experts’ video annotation was assessed by the intra-class correlation coefficient (ICC).ResultsFor FOG assessment in trials without stopping, the agreement of our model was strong (ICC (%TF) = 0.92 [0.68, 0.98]; ICC(#FOG) = 0.95 [0.72, 0.99]). Models trained on a specific FOG-provoking task could not generalize to unseen tasks, while models trained on a specific medication state could generalize to unseen states. For assessment in trials with stopping, the agreement of our model was moderately strong (ICC (%TF) = 0.95 [0.73, 0.99]; ICC (#FOG) = 0.79 [0.46, 0.94]), but only when stopping was included in the training data.ConclusionA TCN trained on IMU signals allows valid FOG assessment in trials with/without stops containing different medication states and FOG-provoking tasks. These results are encouraging and enable future work investigating automated FOG assessment during everyday life.

Changes in gait performances during walking with head movements in older adults with chronic neck pain.

Chronic neck pain (CNP) can lead to altered gait which is worse when combined with head movement. Gait parameters for indicating speed and symmetry have not been thoroughly investigated in older adults with CNP. This study aimed to compare gait performance in term of speed and symmetry in older adults with and without CNP during walking with head movement. Fifty young older adults, consisting of 36 healthy controls without neck pain (OLDs) and 14 older adults with CNP, participated in the study. Participants completed the Neck Disability Index and Activities-specific Balance Confidence Scale. The 10-Meter Walk Test (10MWT) was used to assess gait performance. Participants were instructed to walk at preferred speed under three different head movement patterns: no head movement (NM), horizontal head movement (HM), and vertical head movement (VM). The Inertial Measurement Unit was used to capture gait performance, and its software was used to analyze gait variables; gait speed, Locomotor Rehabilitation Index (LRI), gait asymmetry index, Phase Coordination Index (PCI). The CNP group reported moderate neck pain with mild disability in activities of daily living, and less balance confidence than the OLD group (p < 0.05). The CNP group showed significantly slower gait speed and lower LRI during walking with both the HM and VM (p < 0.05), which corresponded to lower stride length and cadence. The gait asymmetry index in the CNP group was significantly higher than the OLD group during walking with VM (p < 0.05), whereas the PCI was significantly higher than the OLD group during walking with both HM and VM (p < 0.05). Chronic neck pain affects both speed and symmetry when walking with head movement. Gait parameters in this study could be implemented to identify changes in speed and symmetry of gait in older adults with CNP who have mild disability and high physical functioning.

Knee biomechanics variability before and after total knee arthroplasty: an equality of variance prospective study

This study evaluated gait variability in patients before and after total knee arthroplasty (TKA) using the equality of variance method to determine where variability differences occur in the movement cycle. Twenty-eight patients underwent TKA with cruciate-sacrificed implants. Patients underwent motion analysis which measured knee biomechanics as they walked overground at their preferred pace before and 12 months after TKA. Equality of variance results were compared with 14 healthy controls of similar age. Before surgery, patients had reduced knee extension moment variability throughout the early stance phase (4–21% gait cycle, p < 0.05) compared to controls. Knee power variability was lower preoperatively compared to controls for most of the stance phase (0–13% and 17–60% gait cycle, p < 0.05). Sagittal knee moment and power variability further decreased following TKA. Knee extension moment variability was lower postoperatively throughout stance phase compared to preoperatively (4–22% and 36–60% gait cycle, p < 0.05) and compared to controls (4–30% and 45–60% gait cycle, p < 0.05). Knee power variability remained lower following TKA throughout stance phase compared to preoperatively (10–24% and 36–58% gait cycle, p < 0.05) and controls (3–60% gait cycle, p < 0.05). TKA patients may be less stable, and this may be in part due to an unresolved adaptation developed while awaiting TKA surgery and the cruciate sacrificing design of the implants utilized in this study.

Comparison of the Influence of Dual-Task Activities on Prefrontal Activation and Gait Variables in Older Adults with Mild Cognitive Impairment during Straight and Curved Walking.

Background and Objectives: Mild cognitive impairment (MCI) is an early stage of dementia in which everyday tasks can be maintained; however, notable challenges may occur in memory, focus, and problem-solving skills. Therefore, motor-cognitive dual-task training is warranted to prevent cognitive decline and improve cognition in aging populations. This study aimed to determine the influence of such dual-task activities during straight and curved walking on the activities of the prefrontal cortex and associated gait variables in older adults with MCI. Materials and Methods: Twenty-seven older adults aged ≥65 years and identified as having MCI based on their scores (18-23) on the Korean Mini-Mental State Examination were enrolled. The participants performed four task scenarios in random order: walking straight, walking straight with a cognitive task, walking curved, and walking curved with a cognitive task. The activation of the prefrontal cortex, which is manifested by a change in the level of oxyhemoglobin, was measured using functional near-infrared spectroscopy. The gait speed and step count were recorded during the task performance. Results: Significant differences were observed in prefrontal cortex activation and gait variables (p < 0.05). Specifically, a substantial increase was observed in prefrontal cortex activation during a dual task compared with that during a resting-state (p < 0.013). Additionally, significant variations were noted in the gait speed and step count (p < 0.05). Conclusions: This study directly demonstrates the impact of motor-cognitive dual-task training on prefrontal cortex activation in older adults with MCI, suggesting the importance of including such interventions in enhancing cognitive function.

Variability, asymmetry and bilateral coordination of gait during single- and dual-task walking of patients with cerebral small vessel disease

Objective We investigated coefficient of variation (CV), gait asymmetry (GA) and phase coordination index (PCI) in cerebral small vessel disease (CSVD) patients during single-task walking (STW) and dual-task walking (DTW) and explored the relationship between above parameters with disease severity and cognitive function. Methods This cross-sectional study collected cognitive function indices and gait parameters from 23 healthy controls and 94 patients with CSVD during STW and DTW. According to the Fazekas scales, the severity of CSVD valued by white matter hyperintensity (WMH) were divided into control, mild, moderate, severe and control group. MRIs were analyzed for WMHs, CMB, lacunes, etc. Results The control group showed lower PCI than CSVD patients during STW; no differences were detected among the disease severity groups. During DTW, all four groups exhibited significant differences in PCI and CV. For the moderate and severe groups, coordination and variation significantly differed between the two walking methods. There were correlations between the PCI and GA in the moderate and severe groups (R = 0.376, R = 0.573 during DTW; R = 0.414, R = 0.643 during STW) and no correlations in the control group and mild CSVD group. Conclusion PCI and CV may be vital for detecting the symptoms in the early stage of CSVD disease. We also verified that the PCI could become the bridge across the cognition and motor disorder in CSVD, which was helpful for evaluating clinical symptoms comprehensively.

Analysis of veering during gait in blind individuals

BackgroundVeering occurs during blind walking, which causes individuals to deviate from crosswalks or fall off platforms. Despite being linked to static postural control, the relationship between veering and gait function (gait variability and plantar pressure), which is presumed to be related to dynamic postural control, has yet to be fully understood. Research questionHow do gait variability and plantar pressure affect veering? MethodsThis experiment involved a walking task in which 11 blind adults were instructed to walk along a straight path using a white cane. We measured the veering values and analyzed the relationship between gait variability and plantar pressure. ResultsOne participant with a particularly severe veering tendency was excluded from the analysis. Based on the veering characteristics of the participants, the walking trajectories were classified as veering to the left (14 trials) or the right (14 trials) sides. Correlation analysis showed no significant correlation between the veering value and gait variability (vertical, lateral, and anterior-posterior). Plantar pressure (the ball of the fifth toe and the total) was significantly negatively correlate with the veering value. In contrast, the plantar pressure results for the participant who was excluded showed a different characteristic. SignificanceWe hypothesized that blind individuals would exhibit dynamic postural control to stay on a straight path by increasing the plantar pressure on the ball of the fifth toe and the total pressure on the opposite foot when veering occurs. However, this adaptation was not observed in a blind individual with severe veering tendencies.

Graceful gait: virtual ballet classes improve mobility and reduce falls more than wellness classes for older women.

Dance is an effective and motivating form of exercise for older women, but few studies have quantified the benefits of virtual dance classes nor, specifically, ballet. This study tested the effectiveness of virtual ballet compared to virtual wellness classes, with the goal of reaching underserved populations. It is among the first to explore the effects of virtual classical ballet on functional gait mobility, balance, and quality of life measures in older women. Older women were recruited in two waves and randomized to two groups: a ballet class modified for older adults and a wellness-based control class. Both groups received 12 weeks of online classes, meeting twice per week for 45-min sessions. Classes were taught by a local company that offers community-based ballet classes. The same instructor led both the ballet and the wellness classes. Pre- and post-intervention assessments include gait and balance testing using wearable inertial sensors and self-report outcomes including quality of life and mood questionnaires. Forty-four older women completed the study: Ballet group (n = 21, 67.81 ± 7.3 years); Wellness group (n = 23, 69.96 ± 6.7 years). Pre- to post-intervention, both groups increased velocity on the two-minute walk test (F1,42 = 25.36, p < 0.001) and improved their time on the Timed Up and Go (F1,42 = 4.744, p = 0.035). Both groups improved balance on the Mini-BESTest (F1,42 = 38.154, p < 0.001), increased their scores on the Activities-Specific Balance Confidence Scale (F1,42 = 10.688, p < 0.001), and increased quality of life via the Short Form Health Survey (F1,42 = 7.663, p = 0.008). The ballet group improved gait variability in the backward direction (F1,42 = 14.577, p < 0.001) and reduced fall rates more than the wellness group [χ2(1) = 5.096, p = 0.024]. Both virtual ballet and wellness classes improve select measures of gait, balance, and quality of life. The benefits seen in both groups highlight the importance of considering social interaction as a key component when developing future interventions to target mobility in older women.

Between-Day Reliability of the Gait Characteristics and Their Changes During the 6-Minute Walking Test in People With Multiple Sclerosis

Background Gait characteristics and their changes during the 6-minute walking test (6MWT) in people with multiple sclerosis (pwMS) have been described in the literature, which one may refer to as walking fatigability in the body function level of the International Classification of Functioning, Disability, and Health. However, whether these metrics are reliable is unknown. Objective To investigate the between-day reliability of the gait characteristics and their changes in pwMS and healthy controls (HCs). Methods Forty-nine pwMS (EDSS 4.82 ± 1.22 and 54.7 ± 9.36 years) and 23 HCs (50.6 ± 6.1 years) performed the 6MWT, as fast as possible but safely while wearing Inertial Measurement Units. Gait characteristics were measured in the pace, rhythm, variability, asymmetry, kinematics, coordination, and postural control domains and were obtained in intervals of 1 minute during the 6MWT. In addition, gait characteristics change in the last minute compared with the first minute were calculated for all gait variables using a fatigability index (ie, distance walking index). The intraclass correlation coefficient (ICC), Bland–Altman Plots, and Standard error of measurement were applied to investigate reliability. Results Reliability of gait characteristics, minute-by-minute, and for their changes (ie, using the fatigability index) ranged from poor to excellent (pwMS: ICC 0.46-0.96; HC: ICC 0.09-0.97 and pwMS: ICC 0-0.72; HC: ICC 0-0.77, respectively). Conclusion Besides coordination, at least 1 variable of each gait domain showed an ICC of moderate or good reliability for gait characteristics changes in both pwMS and HC. These metrics can be incorporated into future clinical trials and research on walking fatigability. Clinical Trial Registration: NCT05412043.

Alprazolam Reduces Freezing of Gait (FOG) and Improves FOG-Related Gait Deficiencies.

Freezing of gait (FOG) is an intractable motor symptom in Parkinson's disease (PD) that increases fall risk and impairs the quality of life. FOG has been associated with anxiety, with experimental support for the notion that anxiety itself provokes FOG. We investigated the effect of acute anxiety reduction via alprazolam on FOG in PD. In ten patients with PD, FOG, and normal cognition, we administered 0.25 mg alprazolam in one session and placebo in another, in counterbalanced order. At each session, on separate days, patients walked on a pressure-sensitive walkway. Using Oculus Rift virtual-reality goggles, patients walked along a plank that appeared to be (a) level with the floor, in the low-anxiety condition or (b) raised high above the ground, in the high-anxiety conditions. In this way, we assessed the impacts of anxiety and alprazolam (i.e., anxiety reduction) on FOG frequency and other gait parameters. FOG events appeared only in the high-anxiety conditions. Alprazolam significantly reduced subjective and objective measures of anxiety, as well as the prevalence of FOG (p = 0.05). Furthermore, alprazolam improved swing time (p < 0.05) and gait variability in all conditions, particularly during the elevated plank trials. Interpretation. Our results suggest that (1) anxiety induces FOG, and (2) alprazolam concomitantly reduces anxiety and FOG. Alprazolam further improved gait stability (i.e., swing time and gait variability). These findings reveal that anxiety triggers FOG in PD. Treating anxiety can reduce FOG and improve gait stability, potentially offering new therapeutic avenues for this intractable and disabling symptom in PD.

Age and beta amyloid deposition impact gait speed, stride length, and gait smoothness while transitioning from an even to an uneven walking surface in older adults

BackgroundCapturing a measure of movement quality during a complex walking task may indicate the earliest signs of detrimental changes to the brain due to beta amyloid (Aβ) deposition and be a potential differentiator of older adults at elevated and low risk of developing Alzheimer's disease. This study aimed to determine: 1) age-related differences in gait speed, stride length, and gait smoothness while transitioning from an even to an uneven walking surface, by comparing young adults (YA) and older adults (OA), and 2) if gait speed, stride length, and gait smoothness in OA while transitioning from an even to an uneven walking surface is influenced by the amount of Aβ deposition present in an OA's brain. MethodsParticipants included 56 OA (>70 years of age) and 29 YA (25–35 years of age). In OA, Aβ deposition in the brain was quantified by PET imaging. All participants completed a series of cognitive assessments, a functional mobility assessment, and self-report questionnaires. Then participants performed two sets of walking trials on a custom-built walkway containing a mixture of even and uneven surface sections, including three trials with a grass uneven surface and three trials with a rocks uneven surface. Gait data were recorded using a wireless inertial measurement unit system. Stride length, gait speed, and gait smoothness (i.e., log dimensionless lumbar jerk) in the anteroposterior (AP), mediolateral (ML), and vertical (VT) directions were calculated for each stride. Outcomes were retained for five stride locations immediately surrounding the surface transition. ResultsOA exhibited slower gait (Grass: p < 0.001; Rocks: p = 0.006), shorter strides (Grass: p < 0.001; Rocks: p = 0.008), and smoother gait (Grass AP: p < 0.001; Rocks AP: p = 0.002; Rocks ML: p = 0.02) than YA, but they also exhibited greater reductions in gait speed and stride length than YA while transitioning to the uneven grass and rocks surfaces. Within the OA group, those with greater Aβ deposition exhibited decreases in smoothness with age (Grass AP: p = 0.02; Rocks AP: p = 0.03; Grass ML: p = 0.04; Rocks ML: p = 0.03), while those with lower Aβ deposition exhibited increasing smoothness with age (Grass AP: p = 0.01; Rocks AP: p = 0.02; Grass ML: p = 0.08; Rocks ML: p = 0.07). Better functional mobility was associated with less smooth gait (Grass ML: p = 0.02; Rocks ML: p = 0.05) and with less variable gait smoothness (Grass and Rocks AP: both p = 0.04) in the OA group. ConclusionThese results suggest that, relative to YA, OA may be adopting more cautious, compensatory gait strategies to maintain smoothness when approaching surface transitions. However, OA with greater Aβ deposition may have limited ability to adopt compensatory gait strategies to increase the smoothness of their walking as they get older because of neuropathological changes altering the sensory integration process and causing worse dynamic balance (i.e., jerkier gait). Functional mobility, in addition to age and Aβ deposition, may be an important factor of whether or not an OA chooses to employ compensatory strategies to prioritize smoothness while walking and what type of compensatory strategy an OA chooses.

Individuals With Multiple Sclerosis Exhibit More Regular Center of Mass Accelerations After Physical Therapy

ObjectiveThe purpose of this investigation was to explore if a physical therapy program involving strength, flexibility, balance, and walking can improve the uncharacteristic gait variability and overall mobility of persons living with multiple sclerosis (pwMS). DesignPre-post design to evaluate the mobility improvements after undergoing 6 weeks of a gait and balance physical therapy intervention. SettingThe initial 2 weeks were conducted at a medical center under close supervision of a physical therapist. The remaining 4 weeks were performed by the patient at their home and monitored via teleconferences. ParticipantsFifteen pwMS with relapsing-remitting (N=11) or secondary progressive multiple sclerosis (N=4) were enrolled in this study (7 women; mean age: 54.8±9 years; Kurtzke Expanded Disability Status Score range: 3.0-6.5). A group of healthy age-matched controls (N=15) were used for comparisons. InterventionsThe 6-week physical therapy intervention included exercises that targeted strength, flexibility, balance, and walking. The initial 2 weeks of the intervention were performed on-site with the remaining 4 weeks home-based. The therapy was performed twice-a-day for 5 consecutive days each week. Each session was 45 minutes in length. Main Outcome MeasuresPreferred walking speed, spatiotemporal gait kinematics, and a 6-minute walk test were completed before and after therapy. The standard deviation (SD) and sample entropy were used to evaluate the amount of variability and the regularity of the time-dependent variations in the center of mass (COM) accelerations during the 6-minute walk test. ResultsBefore the intervention, the SD of the COM was reduced, and the time-dependent variations were less regular in the pwMS than the control group. After therapy, the SD was 12% larger, and the time-dependent variations were more 7% regular in the pwMS. The effect size for these changes were large (0.91 and 0.94, respectively), suggesting these changes were meaningful. The changes in the regularity of the COM were related to the mobility improvements in the preferred walking velocity and 6-minute walk test. ConclusionsThe results suggest that pwMS have altered COM variability during gait, which can be improved with a similar physical therapy program. These changes appear to be linked with the extent of the mobility improvements.

Ab. No. 149 Therapeutic Effects of Yoga On Gait Variables, Walking Capacity, Balance, Lower Extremity Strength, and Flexibility in Ambulatory Children With Cerebral Palsy

Introduction: The purpose is to explore the effects of Yoga on gait variables, walking capacity, balance, and lower extremity strength and flexibility in ambulatory children with cerebral palsy. Children with cerebral palsy have limited access to skill-based movement programs that combine therapeutic principles of movement rehabilitation with community involvement, the need for activity-grounded therapeutics in cerebral palsy is the need of the hour. Rehabilitation typically focuses on range of motion exercises to prevent and delay contractures, flexibility exercises to increase range of motion, progressive resistance exercises to enhance strength, and varied interventions to improve posture, balance, and the acquisition of functional skills. Thus, the therapeutic movement that improves motor control and imitates social interaction. Methods: Twenty-one children with the potential to participate and corresponding to the inclusion criteria were recruited in the study. The mean average age group of the participants was 8.97 years with 5 girls and 16 boys. Children with cerebral palsy with Gross Motor Function Classification I–III were divided into a control group and an experimental group. Throughout 12 weeks, the control group received conventional physiotherapy treatment while the experimental group an additional one-hour yoga sessions three times each week. The Walking capacity (6 Minute Walk Test), Balance (Pediatric Balance Scale), Muscle strength (Manual Muscle Test Score), and Flexibility (rotational profile using goniometric measurements) were administered before, and after the interventions in each group. Wilcoxon signed-rank test was used to evaluate thedata. Results: Statistically significant differences were found in the walking capacity (p &lt; 0.004), dynamic balance (p 0.002), Strength (p 0.007), and flexibility (p 0.007). Conclusion: Yoga can be used as an adjunct to conventional physiotherapy interventions. Implications: An improvement in walking capacity, and balance leads to increased mobility and improved functional activities of the children with cerebral palsy. As yoga was an additional therapy, this showed better engagement in therapy as it improved the zeal to attend the therapy. These further improved the quality of life as children could engage amongsttheir typically developing peers.