Wider Base Of Support Research Articles

Alterations in Step Width and Reaction Times in Walking Subjects Exposed to Mediolateral Foot-Transmitted Vibration

This study explores how low-frequency foot-transmitted vibration (FTV) affects both gait parameters and cognitive performance. Twenty healthy male participants experienced harmonic mediolateral FTV (1.25 Hz, 1 m/s2) while either standing or walking on a treadmill. We assessed participants’ reaction times to visual stimuli using a psychomotor vigilance task (PVT) test under five conditions, including (i) baseline (standing still without vibration), (ii) vibration (standing still with vibration), (iii) walking (walking without vibration), (iv) walking with vibration, and (v) post-test (standing still without vibration after the tests). Additionally, the step width (SW) was measured with a camera system in conditions (iii) and (iv), i.e., when participants were walking with and without vibration and during PVT execution. The results showed that the average vigilance decreased, and the step width increased while walking and/or with vibration exposure. These findings suggest a potential connection between decreased vigilance, increased step width, and the need for enhanced stability, focusing on balance maintenance and a wider base of support. Implications for future standard revisions are presented and discussed.

Characterizing ambulatory function in children with PPP2R5D-related neurodevelopmental disorder

BackgroundIndividuals with PPP2R5D-related neurodevelopmental disorder have an atypical gait pattern characterized by ataxia and incoordination. Structured, quantitative assessments are needed to further understand the impact of these impairments on function. Research questionHow do gait parameters and ambulatory function of individuals with PPP2R5D-related neurodevelopmental disorder compare to age and sex matched healthy norms? MethodsTwenty-six individuals with PPP2R5D pathogenic genetic variants participated in this observational, single visit study. Participants completed at least one of the following gait assessments: quantitative gait analysis at three different speeds (preferred pace walking (PPW), fast paced walking (FPW) and running, six-minute walk test (6MWT), 10-meter walk run (10MWR), and timed up and go (TUG). Descriptive statistics were used to summarize gait variables. Percent of predicted values were calculated using published norms. Paired t-tests and regression analyses were used to compare gait variables. ResultsThe median age of the participants was 8 years (range 4–27) and eighteen (69.2 %) were female. Individuals with PPP2R5D-related neurodevelopmental disorder walked slower and with a wider base of support than predicted for their age and sex. Stride velocity ranged from 48.9 % to 70.1 % and stride distance from 58.5 % to 81.9 % of predicted during PPW. Percent of predicted distance walked on the 6MWT ranged from 30.6 % to 71.1 % representing varied walking impairment. Increases in stride distance, not cadence, were associated with changes in stride velocity in FPW (R2 = 0.675, p =< 0.001) and running conditions (R2 = 0.918, p =< 0.001). SignificanceWe quantitatively assessed the abnormal gait in individuals with PPP2R5D-related neurodevelopmental disorder. These impairments may affect ability to adapt to environmental changes and participation in daily life.Rehabilitative interventions targeting gait speed and balance may improve function and safety for individuals with PPP2R5D-related neurodevelopmental disorder.

Motion acquisition of gait characteristics one week after total hip arthroplasty: a factor analysis

IntroductionClinical gait analysis can be used to evaluate the recovery process of patients undergoing total hip arthroplasty (THA). The postoperative walking patterns of these patients can be significantly influenced by the choice of surgical approach, as each procedure alters distinct anatomical structures. The aim of this study is twofold. The first objective is to develop a gait model to describe the change in ambulation one week after THA. The secondary goal is to describe the differences associated with the surgical approach.Materials and methodsThirty-six patients undergoing THA with lateral (n = 9), anterior (n = 15), and posterior (n = 12) approaches were included in the study. Walking before and 7 days after surgery was recorded using a markerless motion capture system. Exploratory Factor Analysis (EFA), a data reduction technique, condensed 21 spatiotemporal gait parameters to a smaller set of dominant variables. The EFA-derived gait domains were utilized to study post-surgical gait variations and to compare the post-surgical gait among the three groups.ResultsFour distinct gait domains were identified. The most pronounced variation one week after surgery is in the Rhythm (gait cycle time: +32.9%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$+32.9\\mathrm{\\%}$$\\end{document}), followed by Postural control (step width: +27.0%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$+27.0\\mathrm{\\%}$$\\end{document}), Phases (stance time: +11.0%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$+11.0\\%$$\\end{document}), and Pace (stride length: − 9.3%\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$9.3\\%$$\\end{document}). In postsurgical walking, Phases is statistically significantly different in patients operated with the posterior approach compared to lateral (p-value = 0.017) and anterior (p-value = 0.002) approaches. Furthermore, stance time in the posterior approach group is significantly lower than in healthy individuals (p-value < 0.001).ConclusionsThis study identified a four-component gait model specific to THA patients. The results showed that patients after THA have longer stride time but shorter stride length, wider base of support, and longer stance time, although the posterior group had a statistically significant shorter stance time than the others. The findings of this research have the potential to simplify the reporting of gait outcomes, reduce redundancy, and inform targeted interventions in regards to specific gait domains.

Postural stability of adults with down syndrome – differences between women and men

ObjectiveThis study aimed to analyse differences in postural stability (PS) between adults with Down syndrome (DS) and adults without DS of the same age and to compare the PS between men and women with DS.MethodsTwenty-six individuals with DS (mean age 38.4 ± 8.7 yrs.) and 26 individuals without DS (mean age 38.8 ± 9.2 yrs.) participated in the study. Postural stability was measured using a pressure sensing platform MobileMat 3140 (Tekscan) in these modifications of the bipedal stance: a. wide base of support with the eyes open (WO); b. wide base of support with the eyes closed (WC); c. narrow base of support with the eyes open (NO). Six parameters of PS were compared in the statistical analysis: centre of pressure (COP) path length, COP excursion front-back, COP excursion left-right, COP velocity average, time to boundary (TTB) front-back, and TTB left-right.ResultsMost PS variables (COP path length, COP excursion left-right, COP velocity average, TTB front-back) indicate significantly lower PS of adults with DS than that of the reference group (p < 0.05). Some PS variables (COP path length and COP velocity average in WC, COP excursion front-back and COP excursion left-right in NO) showed differences between men and women in more demanding conditions, indicating lower PS in men with DS.

Relationship between stair ascent gait speed, bone density and gait characteristics of postmenopausal women.

Stair ascent is a biomechanically challenging task for older women. Bone health may affect gait stability during stair walking. This study investigated the gait biomechanics associated with stair ascent in a group of postmenopausal women in relation to walking speed and bone health, quantified by T-score. Forty-five healthy women (mean (SD) age: 67 (14) years), with bone density ranging from healthy to osteoporotic (T-score range +1 to -3), ascended a custom-made five-step staircase with two embedded force plates, surrounded by 10 motion capture cameras, at their self-selected speed. Multivariate regression analyses investigated the explained variance in gait parameters in relation to stair ascent speed and T-score of each individual. Stair ascent speed was 0.65 (0.1) m·s-1 and explained the variance (R2 = 9 to 47%, P ≤ 0.05) in most gait parameters. T-score explained additional variance in stride width (R2 = 20%, P = 0.014), pelvic hike (R2 = 19%, P = 0.011), pelvic drop (R2 = 21%, P = 0.007) and hip adduction (R2 = 7%, P = 0.054). Increased stride width, and thereby a wider base of support, accompanied by increased frontal plane hip kinematics, could be important strategies to improve dynamic stability during stair ascent among this group of women. These findings suggest that targeted exercises of the hip abductors and adductors, including core trunk musculature, could improve dynamic stability during more challenging locomotor tasks. Balance exercises that challenge base of support could also benefit older women with low bone mineral density who may be at risk of falls.

Longitudinal relationships between disability and gait characteristics in people with MS

Longitudinal data are vital in order to understand intra individual gait changes with the progression of multiple sclerosis (MS). Therefore, the primary aim of this study was to explore the relationship between changes in disability with changes in major spatio-temporal parameters of gait in people with MS (PwMS). PwMS (n = 83) completed two gait assessments performed at separate time points (M1, M2). For each individual, the absolute difference between the Expanded Disability Status Scale (EDSS) score, key spatio-temporal parameters of gait, Falls Efficacy Scale International (FES-I), and the 12-item Multiple Sclerosis Walking Scale (MSWS-12), were calculated. The mean time difference between M1 and M2 was 2.5 (SD = 1.7) years. At M2, PwMS presented with shorter strides, a wider base of support, increased perceived mobility difficulties and fear of falling compared with M1. According to the odds ratio (OR) analysis, the odds of experiencing an increase in the EDSS score was significantly higher once the MSWS-12 score increased at M2 compared with M1 (OR = 7.930, p = 0.004). This observation was highlighted specifically in people with mild-moderate MS (OR = 12.427, p < 0.001). The increase in the EDSS score was not associated with changes in key spatio-temporal parameters of gait. The present study provides a better understanding of gait and disease progression in PwMS, highlighting the significant role of the MSWS-12.

A systematic video analysis of 21 anterior cruciate ligament injuries in elite netball players during games

ABSTRACT This systematic video analysis of 21 anterior cruciate ligament (ACL) injuries sustained by elite-level netball players during televised games, describes the situation, movement pattern and player behaviour, providing insight regarding the injury mechanism. Seventeen of the ACL injuries occurred from jump-landing actions and only two from cutting manoeuvres. A common scenario was identified for 11 players. In this scenario, players were decelerating rapidly after jumping to receive a high pass, utilising a double-footed landing with a wide base of support (WBOS). Deceleration appeared to be applied predominantly via the injured leg with the knee extended and foot planted. Often the players appeared unbalanced on landing leaning too far back. ACL injury risk was possibly exacerbated by the players head turning away from the injured side. A further compressive knee moment may have been placed on the lateral aspect of the knee by bringing the ball from a high position to a low position at the estimated time of injury. Players may benefit from landing technique training programmes that encourage shoulder-width foot landings, with ≥30° knee flexion, a small amount of plantar-flexion and good balance. Incorporating challenges to players balance and ability to cope with perturbations may also be beneficial. Training programmes should include instruction on securing the ball in a stable above pelvis-level position after receiving a pass and bringing their whole body around during landing into the direction of their next pass, rather than simply turning their head to look.

Yoga Balance: Decreasing Fall Risk in Seniors

<h3>Research Objectives</h3> To investigate the effect of yoga in decreasing fall risk for activities of daily living and community mobility in the senior population thru occupational therapy. <h3>Design</h3> Basic yoga poses related to primal movement were selected/ executed with NDT techniques; 1 year. <h3>Setting</h3> Continuing Care Retirement Community(CCRC). <h3>Participants</h3> 10 clients with inclusion criteria of age 80+, live in the CCRC, can include co-morbidities, joint replacements accepted. <h3>Interventions</h3> Example of pose: horse stance was selected because as children we have a wide base of support with hips in external rotation and equine stance. Overtime this integrates to a narrower base of support, external/ internal rotation equalizes, and equine stance becomes plantar. Utilizing poses that follow typical patterns allows for neuro plasticity to engage in a way it has before enhancing the progression of decreased fall risk as it relates to ADL's. Alignment is key when addressing posture and fall risk in occupational therapy as well as in Iyengar yoga. Used handling techniques, visual work (mirror), and verbal cueing. Cues were a combination of OT and yogic cues to create proper alignment. Handling promoted neck retraction, scapular depression/ stabilization, shoulder/ pelvic girdle anterior alignment, and knee/ ankle alignment. <h3>Main Outcome Measures</h3> Tinetti: scores increased by an average of 11 points. <h3>Results</h3> When used as an individual therapeutic intervention yoga postures with NDT regressive handling techniques increases the Tinetti score by an average of 11 points; proving a marked decrease of fall risk for ADL's in seniors. Secondary outcomes that were reported by patients included scoliosis curvature decrease, bladder control improvement, and an increased ability to orgasm. <h3>Conclusions</h3> With an average number of Tinetti score improvement by 11 for the total of 10 clients with no regression this study does prove that yoga is effective in decreasing fall risk in seniors. Due to our results we believe expanded studies utilizing yoga as an individualized intervention during therapy sessions is necessary to promote decreased fall risk in elderly patients. <h3>Author(s) Disclosures</h3> N/A.

Gait Characteristics in Youth With Transverse Myelitis.

Transverse myelitis (TM) in childhood is a rare disorder characterized by the presence of spinal cord inflammation. Gait difficulty in children with TM is common; however, there is a paucity of literature regarding quantitative assessment of gait in children and adolescents with TM. To characterize gait patterns in a cohort of ambulatory children with TM and age-matched, typically developing peers in order to better understand the functional mobility of patients diagnosed with childhood TM. This was a retrospective study of 26 ambulatory pediatric patients with a confirmed diagnosis of TM who had undergone three-dimensional, instrumented gait analysis (3D-IGA) at 3 years of age or older. A group of 38 typically developing children served as a control group. Gait in children with TM was characterized by moderate kinematic deviations as measured by the Gait Deviation Index (GDI) and a crouched gait pattern (p < .001), increased anterior pelvic tilt (p < .001), decreased motion at the knees (p < .001), and a wider base of support (foot progression angle, p < .001). The TM group had a slower walking speed (p < .001), shorter strides (p < .001), and an increased stance phase compared to controls. Our study results showed moderate kinematic deviations quantified by the GDI. Overall, the gait pattern in the TM population tested had greater hip and knee flexion with wider foot progression angle. Identification of gait characteristics in children with TM is the first step in predicting changes in gait pattern as they mature over time, which may ultimately allow for targeted intervention to maintain their ambulatory function.

Alternating hemiplegia of childhood: evolution over time and mouse model corroboration.

Alternating hemiplegia of childhood is a rare neurodevelopmental disorder caused by ATP1A3 mutations. Some evidence for disease progression exists, but there are few systematic analyses. Here, we evaluate alternating hemiplegia of childhood progression in humans and in the D801N knock-in alternating hemiplegia of childhood mouse, Mashlool, model. This study performed an ambidirectional (prospective and retrospective data) analysis of an alternating hemiplegia of childhood patient cohort (n = 42, age 10.24 ± 1.48 years) seen at one US centre. To investigate potential disease progression, we used linear mixed effects models incorporating early and subsequent visits, and Wilcoxon Signed Rank test comparing first and last visits. Potential early-life clinical predictors were determined via multivariable regression. We also compared EEG background at first encounter and at last follow-up. We then performed a retrospective confirmation study on a multicentre cohort of alternating hemiplegia of childhood patients from France (n = 52). To investigate disease progression in the Mashlool mouse, we performed behavioural testing on a cohort of Mashlool- mice at prepubescent and adult ages (n = 11). Results: US patients, over time, demonstrated mild worsening of non-paroxysmal disability index scores, but not of paroxysmal disability index scores. Increasing age was a predictor of worse scores: P < 0.0001 for the non-paroxysmal disability index, intellectual disability scale and gross motor scores. Earliest non-paroxysmal disability index score was a predictor of last visit non-paroxysmal disability index score (P = 0.022), and earliest intellectual disability score was a predictor of last intellectual disability score (P = 0.035). More patients with EEG background slowing were noted at last follow-up as compared to initial (P = 0.015). Similar worsening of disease with age was also noted in the French cohort: age was a significant predictor of non-paroxysmal disability index score (P = 0.001) and first and last non-paroxysmal disability index score scores significantly differed (P = 0.002). In animal studies, adult Mashlool mice had, as compared to younger Mashlool mice, (i) worse balance beam performance; (ii) wider base of support; (iii) higher severity of seizures and resultant mortality; and (iv) no increased predisposition to hemiplegic or dystonic spells. In conclusion, (i) non-paroxysmal alternating hemiplegia of childhood manifestations show, on average over time, progression associated with severity of early-life non-paroxysmal disability and age. (ii) Progression also occurs in Mashlool mice, confirming that ATP1A3 disease can lead to age-related worsening. (iii) Clinical findings provide a basis for counselling patients and for designing therapeutic trials. Animal findings confirm a mouse model for investigation of underlying mechanisms of disease progression, and are also consistent with known mechanisms of ATP1A3-related neurodegeneration.

Lower Limb Movement Pattern Differences Between Males and Females in Squatting and Kneeling.

Movement pattern differences may contribute to differential injury or disease prevalence between individuals. The purpose of this study was to identify lower limb movement patterns in high knee flexion, a risk factor for knee osteoarthritis, and to investigate kinematic differences between males and females, as females typically develop knee osteoarthritis more commonly and severely than males. Lower extremity kinematic data were recorded from 110 participants completing 4 variations of squatting and kneeling. Principal component analysis was used to identify principal movements associated with the largest variability in the sample. Across the tasks, similar principal movements emerged at maximal flexion and during transitions. At maximal flexion, females achieved greater knee flexion, facilitated by a wider base of support, which may alter posterior and lateral tibiofemoral stress. Principal movements also detected differences in movement temporality between males and females. When these temporal differences occur due to alterations in movement velocity and/or acceleration, they may elicit changes in muscle activation and knee joint stress. Movement variability identified in the current study provides a framework for potential modifiable factors in high knee flexion, such as foot position, and suggests that kinematic differences between the sexes may contribute to differences in knee osteoarthritis progression.

Bidirectional causal control in the dynamics of handstand balance

The aim of this study was to identify motor control solutions associated with the ability to maintain handstand balance. Using a novel approach, we investigated the dynamical interactions between centre of pressure (CoP) and centre of mass (CoM) motion. A gymnastics cohort was divided into a ‘less skilled’ group, who held handstands for 4–6 s, and a ‘more skilled’ group, who held handstands in excess of 10 s. CoP–CoM causality was investigated in anterior–posterior (AP) and medio-lateral (ML) directions, in addition to time–space, time–frequency and Hurst Exponent (H) analyses. Lower AP CoP to CoM causal drive and lower H values (> 0.6) indicated the more skilled gymnasts were less reliant on CoP mechanics to drive CoM motion. More skilled performance demonstrated greater adaptability through use of reactive, as opposed to anticipatory, control strategies. Skilled performers additionally exploited mechanical advantages in ML (e.g. a wider base of support), compared to the less skilled athletes. A multiple regression analysis revealed H and frequency domain measures to be better predictors of handstand balance duration than time–space domain measures. The study findings highlight the advantage of an adaptable motor control system with a directional profile, and provide new insight into the clear, measurable footprint of CoP on the dynamics of CoM.

Persistent Gait Stability Deficits Associated With History Of Concussion

Postural instability during gait is a common symptom following a concussion and is often used as a diagnostic criterion. Specialized equipment has been able to detect impairments in gait patterns and center of pressure (COP) displacement weeks following a concussion. However, difficulty maintaining balance during gait is often not considered when determining whether a concussed individual has made a full recovery unless the impairments are grossly detrimental in nature. PURPOSE: To determine if deficits in gait stability seen in concussed individuals persist long after the reception of medical clearance from the initial injury. METHODS: Gait parameters were collected using a 20 ft. instrumented pressure-sensitive walkway. Healthy participants reporting a prior history of concussion (n=25) and those reporting no concussion history serving as controls (n=21) were recruited to participate. Individuals with previous history of concussion averaged 7.27 ± 5.73 years since their most recent injury. Participants were instructed to walk in their normal, preferred gait pattern while looking straight ahead. Participants then walked using a tandem gait pattern, walking heel-to-toe in line with each step while looking straight ahead. RESULTS: Individuals with prior history of concussion demonstrated significantly greater stride width compared to controls during normal, preferred gait (7.83 cm vs. 10.29 cm, p = 0.09) and tandem gait (0.17 cm vs. 1.63 cm, p = 0.01). Additionally, previously concussed individuals displayed significantly greater single-support COP path length during normal, preferred gait (12.08 cm vs. 12.97 cm, p = 0.06) and significantly greater double-support COP path length during tandem gait (22.71 cm vs. 24.69 cm, p = 0.01). CONCLUSION: Individuals that have a sustained one or more concussions demonstrate greater instability in their gait patterns as demonstrated by a wider base of support and greater instability in stance phase during gait years following the initial injury as well as reception of medical clearance. These findings suggest that concussion is associated with long-term impairment in an individual’s ability to maintain postural stability during gait, and that individuals with a prior history of concussion will adopt more conservative gait patterns in order to compensate.

Feature Detection and Biomechanical Analysis to Objectively Identify High Exposure Movement Strategies When Performing the EPIC Lift Capacity test.

Purpose The Epic Lift Capacity (ELC) test is used to determine a worker's maximum lifting capacity. In the ELC test, maximum lifting capacity is often determined as the maximum weight lifted without exhibiting a visually appraised "high-risk workstyle." However, the criteria for evaluating lifting mechanics have limited justification. This study applies feature detection and biomechanical analysis to motion capture data obtained while participants performed the ELC test to objectively identify aspects of movement that may help define "high-risk workstyle". Method In this cross-sectional study, 24 participants completed the ELC test. We applied Principal Component Analysis, as a feature detection approach, and biomechanical analysis to motion capture data to objectively identify movement features related to biomechanical exposure on the low back and shoulders. Principal component scores were compared between high and low exposure trials (relative to median exposure) to determine if features of movement differed. Features were interpreted using single component reconstructions of principal components. Results Statistical testing showed that low exposure lifts and lowers maintained the body closer to the load, exhibited squat-like movement (greater knee flexion, wider base of support), and remained closer to neutral posture at the low back (less forward flexion and axial twist) and shoulder (less flexion and abduction). Conclusions Use of feature detection and biomechanical analyses revealed movement features related to biomechanical exposure at the low back and shoulders. The objectively identified criteria could augment the existing scoring criteria for ELC test technique assessment. In the future, such features can inform the design of classifiers to objectively identify "high-risk workstyle" in real-time.

Evaluation of Standing Balance Performance in Indian Classical Dancers.

Indian classical dance involves a constant change of the base of support from stance to low jumps and spins along with intricate footwork. Graceful movement of the torso, shifting from side to side and turning around the axis of the spine, challenges balance. Yet, balance performance remains unexplored in Indian classical dancers. Therefore, the present study aimed to compare the standing balance of 36 active female dancers (18 to 25 years of age) who had performed Indian classical dance for a minimum of 10 years with 36 healthy age-matched women not involved in regular physical activity. Balance was evaluated in static and dynamic conditions of single and dual-limb stance on a force plate using center-of-pressure trajectory and the Star Excursion Balance Test (SEBT). Dancers demonstrated better balance on both instrumented and non-instrumented outcome variables: wide base of support with eyes open and with eyes closed; for 30-second single limb stance with eyes open and with eyes closed; for 13-second dual task in single limb stance; and for 22-second dual task in wide base of support. The SEBT revealed significantly better balance performance of dancers in the three directions tested: anterior, posteromedial, and posterolateral. There was also a strength component of the study on which the dancers achieved significantly higher scores than controls for the three muscle groups tested (gastrocsoleus, gluteus medius, and quadriceps), which can be attributed to their training. These findings can be used to recommend classical dance training to achieve the dual purpose of deriving better balance and stronger bodies and maintaining the Indian dance heritage.

EFFECT OF SELF-PACED WALKING ON REDUCING COGNITIVE DEMANDS OF WALKING WHILE TALKING

Although walking is considered an automated process, internal and external factors can alter gait performance. Fear of falling leads to walking with a wider base of support and decreased walking speed, due to a combination of shorter stride lengths and/or stride time. Exacerbation of gait deficits have been reported under high cognitive load situations (HCLS, also known as dual-tasks). Talking on a phone is considered an increased HCLS over talking in-person due to visualization of the individual on the phone. The purpose of the study was to explore the added effects of walking while talking on a phone compared to talking in-person. Fifteen healthy older adult subjects (70.86±4.7yrs) performed three conditions while walking on a self-paced treadmill for ten minutes: (1)walking alone, (2)walking while talking in-person, (3)walking while talking on a phone. Mean stride length(SL), stride time(ST), and step width(SW) were compared using one-way, repeated-measures ANOVAs (p=0.10). Dual-task cost of walking while talking in-person and on a phone was calculated for each gait variable and compared with t-tests. Mean gait variables did not differ between conditions (SL p=0.95, ST p=0.77, SW p=0.57). Dual-task costs were not significantly different between talking conditions (SL p=0.99, ST p=0.54, SW p=0.14). Use of a self-paced treadmill allowed the subjects to perform in their “comfort zone”, however, walking on a set-speed treadmill may force walking speed outside of the comfort zone, pushing one’s “reserve”, and revealing differences. Use of a self-paced treadmill better approximates daily life by providing the opportunity to make adaptations under HCLS.

Frontal vs. Posterior cognitive dysfunction: Does greater risk of dementia lead to a differential gait in Parkinson’s disease?

Background: Gait impairment is suggested to predict the onset of dementia in Parkinson’s disease (PD). Interestingly, studies have shown that PD patients with cognitive deficits mediated by posterior brain areas are at greater risk of developing dementia than those with frontal deficits. Yet, it remains unknown whether PD patients with posterior cognitive deficits show differences in gait when compared to those with frontal deficits. Aim: This study aimed to compare gait of individuals with PD showing “posterior”, “frontal”, or no cognitive impairment (NCI). Methods: Based on a sample of 64 individuals with PD, median scores were calculated for three neuropsychological tests relying on “frontal” and three relying on “posterior” brain areas. Individuals assigned into the Frontal or Posterior groups showed at least 2 out of 3 scores lower than the median in frontal or posterior tests, respectively. Those with 0 or 1 score lower than the median were classified as NCI. Participants walked under single and dual task conditions. Results: All groups walked slower, with greater variability, wider base of support, and longer double support in the dual task condition. Interpretation: PD patients with posterior cognitive deficits walk similarly to those with frontal deficits and those with normal cognition.

Effects of repeated waist-pull perturbations on gait stability in subjects with cerebellar ataxia

BackgroundDamage to the cerebellum can affect neural structures involved in locomotion, causing gait and balance disorders. However, the integrity of cerebellum does not seem to be critical in managing sudden and unexpected environmental changes such as disturbances during walking. The cerebellum also plays a functional role in motor learning. Only a few effective therapies exist for individuals with cerebellar ataxia. With these in mind, we aimed at investigating: (1) corrective response of participants with cerebellar ataxia (CA) to unexpected gait perturbations; and (2) the effectiveness of a perturbation-based training to improve their dynamic stability during balance recovery responses and steady walking. Specifically, we hypothesized that: (1) CA group can show a corrective behavior similar to that of a healthy control group; (2) the exposure to a perturbation-based treatment can exploit residual learning capability, thus improving their dynamic stability during balance recovery responses and steady locomotion.MethodsTen participants with cerebellar ataxia and eight age-matched healthy adults were exposed to a single perturbation-based training session. The Active Tethered Pelvic Assist Device applied unexpected waist-pull perturbations while participants walked on a treadmill. Spatio-temporal parameters and dynamic stability were determined during corrective responses and steady locomotion, before and after the training. The ANalysis Of VAriance was the main statistical test used to assess the effects of group (healthy vs CA) and training (baseline vs post) on spatio-temporal parameters of the gait and margin of stability.ResultsData analysis revealed that individuals with cerebellar ataxia behaved differently from healthy volunteers: (1) they retained a wider base of support during corrective responses and steady gait both before and after the training; (2) due to the training, patients improved their anterior-posterior margin of stability during steady walking only.ConclusionsOur results revealed that participants with cerebellar ataxia could still rely on their learning capability to modify the gait towards a safer behavior. However, they could not take advantage from their residual learning capability while managing sudden and unexpected perturbations. Accordingly, the proposed training paradigm can be considered as a promising approach to improve balance control during steady walking in these individuals.

Visually-guided saccades attenuate postural sway under non-fatigued, fatigued, and stretched states.

Muscular fatigue, which reduces force output and position sense, often leads to increased sway and potential balance impairments. In contrast, visually-guided saccadic eye movements (saccades) can attenuate sway more than fixating gaze on an external target. The goals of this study were to determine whether the use of saccades could reduce the increased postural sway in a fatigued state and to better understand the contributions to fatigue-induced increased sway. We compared the effects of gazing at a fixation point (FP) and performing saccades (SAC) on various spatial and temporal measures of the center of pressure (CoP) while participants stood as still as possible on a force plate. Participants used either a narrow or wide base of support and performed three trials for each eye movement condition (SAC, FP) in three states (non-fatigued-NF, stretched-S, and fatigued-F). Calf raises to exhaustion induced ankle fatigue. Extreme plantar- and dorsi-flexion induced stretch. SAC significantly decreased sway and increased time-series complexity (sample entropy) compared to FP. F increased sway and decreased time-series complexity compared to NF and S states, which were similar. Reduced force production, which accompanies muscle fatigue and stretching, did not account for increased sway associated with acute bouts of ankle muscle fatigue. Increased position sense often associated with muscle stretching likely compensated for any reduced force output for S, while the decreased position sense associated with F probably explained the increased sway in this state. Performing saccadic eye movements during quiet stance can help reduce sway under various states.

Gait and footwear in children and adolescents with Charcot-Marie-Tooth disease: A cross-sectional, case-controlled study

ObjectiveChildren with Charcot-Marie-Tooth disease (CMT) report problems with gait and footwear. We evaluated differences in spatio-temporal gait variables and gait variability between children with CMT and typically developing (TD) children, and investigated the effect of footwear upon gait. MethodA cross-sectional study of 30 children with CMT and 30 age- and gender-matched TD children aged 4–18 years. Gait was assessed at self-selected speed on an electronic walkway while barefoot and in two types of the child’s own footwear; optimal (e.g., athletic-type runners) and suboptimal (e.g., flip-flops). ResultsChildren with CMT walked more slowly (mean (SD) −13.81 (3.61) cm/s), with shorter steps (−6.28 (1.37) cm), wider base of support (+2.47 (0.66) cm; all p < 0.001) and greater base of support variability (0.48 (0.15) cm, p = 0.002) compared to TD children. Gait was faster in optimal footwear than suboptimal (−7.55 (1.31) cm/s) and barefoot (−7.42 (1.07) cm/sec; both p < 0.001) in the combined group of children. Gait in suboptimal footwear was more variable compared to barefoot and optimal footwear. Greater base of support variability and reduced balance was moderately correlated for both groups (CMT and TD). ConclusionGait is slower with shorter, wider steps and greater base of support variability in children with CMT. Poor balance is associated with greater base of support gait variability. Suboptimal footwear negatively affects gait in all children (CMT and TD), which has clinical implications for children and adolescents with CMT who have weaker feet and ankles, and poor balance.