Changes In Gait Speed Research Articles

Cerebral microhemorrhages impair gait coordination in mice

Impairment in gait coordination and the consequent risk of falling are important problems in the rapidly aging population of the Western world: clinically diagnosable gait abnormalities affect approximately 35% of adults over age 70. While musculoskeletal mechanisms and processes have been extensively studied, factors affecting central neural control of gait coordination in older adults without overt neurological diseases are much less understood. Recent studies raise the possibility that in addition to causing cognitive decline, age‐associated cerebromicrovascular pathologies also contribute to mobility disability. However, the specific microvascular mechanisms underlying the loss of gait coordination in aging are not completely understood. Cerebral microhemorrhages (CMHs) are associated with rupture of small intracerebral vessels and cause focal disruption of neuronal networks. While there is growing evidence that CMHs predict cognitive impairment, the association between CMHs and gait abnormalities have not been investigated. The present study was designed to provide proof‐of‐concept that CMHs are causally linked to progressive gait dysfunction. To achieve this goal, we adapted a model of hypertension‐induced CMHs in mice (treatment with angiotensin II plus the NO synthase inhibitor L‐NAME). Computerized gait analysis was performed daily (Noldus CatWalk). CMHs were verified histologically. Mice with CMHs showed significantly altered gait function as measured by stride length, stride time and stride length variability, changes in phase‐dispersion and gait speed. CMH burden also correlated changes in the regularity index (a measure of inter‐paw coordination). Collectively, hypertension‐induced CMHs result in detectable impairment of gait function in mice. Further studies to analyze association of CMHs with gait abnormalities in human patients are warranted.Support or Funding InformationThis work was supported by grants from the American Heart Association, the National Center for Complementary and Alternative Medicine, and the National Institute on AgingThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Relationship of Physical Function to Single Muscle Fiber Contractility in Older Adults: Effects of Resistance Training With and Without Caloric Restriction.

Previous studies support beneficial effects of both resistance exercise training (RT) and caloric restriction (CR) on skeletal muscle strength and physical performance. The goal of this study was to determine the effects of adding CR to RT on single-muscle fiber contractility responses to RT in older overweight and obese adults. We analyzed contractile properties in 1,253 single myofiber from muscle biopsies of the vastus lateralis, as well as physical performance and thigh muscle volume, in 31 older (65-80 years), overweight or obese (body mass index = 27-35 kg/m2) men (n = 19) and women (n = 12) who were randomly assigned to a standardized, progressive RT intervention with CR (RT+CR; n = 15) or without CR (RT; n = 16) for 5 months. Both interventions evoked an increase in force normalized to cross-sectional area (CSA), in type-I and type-II fibers and knee extensor quality. However, these improvements were not different between intervention groups. In the RT group, changes in total thigh fat volume inversely correlated with changes in type-II fiber force (r = -.691; p = .019). Within the RT+CR group, changes in gait speed correlated positively with changes in type-I fiber CSA (r = .561; p = .030). In addition, increases in type-I normalized fiber force were related to decreases in thigh intermuscular fat volume (r = -0.539; p = .038). Single muscle fiber force and knee extensor quality improve with RT and RT+CR; however, CR does not enhance improvements in single muscle fiber contractility or whole muscle in response to RT in older overweight and obese men and women.

Physiotherapy Effects in Gait Speed in Patients with Knee Osteoarthritis.

BACKGROUND:Knee osteoarthritis is a chronic degenerative disease, known as the most common cause of difficulty walking in older adults and subsequently is associated with slow walking. Also one of the main symptoms is a degenerative and mechanics type of pain. Pain is very noticeable while walking in rugged terrain, during ascent and descent of stairs, when changing from sitting to standing position as well as staying in one position for a long time. Many studies have shown that the strength of the quadriceps femoris muscle can affect gait, by improving or weakening it. Kinesio Tape is a physiotherapeutic technique, which reduces pain and increases muscular strength by irritating the skin receptors.AIM:The aims of this study was first to verify if the application of Kinesio Tape on quadriceps femoris muscle increases gait speed in patients with knee osteoarthritis and secondly if applying Kinesio Tape on quadriceps femoris muscle reduces pain while walking.METHOD:Seventy-four patients with primary knee osteoarthritis, aged 50 - 73 years, participated in this study. Firstly we observed the change of gait speed, while walking for 10 meters at normal speed for each patient, before, one day and three days after the application of Kinesio Tape on quadriceps femoris muscle, with the help of the 10 - meter walk test. Secondly, we observed the change of pain, while walking for 10 meters at normal speed for each patient, before, one day and three days after the application, with the help of Numerical Pain Rating Scale - NRS.RESULTS:Our results indicated that there was a significant increase in gait speed while walking for 10 meters one day and also three days after application of Kinesio Tape on quadriceps femoris muscle. Also, there was a significant reduction of pain level 1 and 3 days after application of Kinesio Tape, compared to the level of pain before its application.CONCLUSIONS:Our results indicated that there was a significant decrease in pain and increase of gait speed while walking for 10 meters. Kinesio Tape can be used in patients with knee osteoarthritis, especially when changing walking stereotypes is a long-term goal of the treatment.

36-Item Short Form Survey (SF-36) Versus Gait Speed As Predictor of Preclinical Mobility Disability in Older Women: The Women's Health Initiative.

To compare the value of clinically measured gait speed with that of the self-reported Medical Outcomes Study 36-item Short-Form Survey Physical Function Index (SF-36 PF) in predicting future preclinical mobility disability (PCMD) in older women. Prospective cohort study. Forty clinical centers in the United States. Women aged 65 to 79 enrolled in the Women's Health Initiative Clinical Trials with gait speed and SF-36 assessed at baseline (1993-1998) and follow-up Years 1, 3, and 6 (N = 3,587). Women were categorized as nondecliners or decliners based on changes (from baseline to Year 1) in gait speed and SF-36 PF scores. Logistic regression models were used to estimate incident PCMD (gait speed <1.0 m/s) at Years 3 and 6. Area under the receiver operating characteristic curve (AUC) was used to compare the predictive value of SF-36 PF with that of measured gait speed. Slower baseline gait speed and lower SF-36 PF scores were associated with higher adjusted odds of PCMD at Years 3 and 6 (all P < .001). For gait speed, decliners were 2.59 times as likely to have developed PCMD as nondecliners by Year 3 and 2.35 times as likely by Year 6. Likewise, for SF-36, decliners were 1.42 times as likely to have developed PCMD by Year 3 and 1.49 times as likely by Year 6. Baseline gait speed (AUC = 0.713) was nonsignificantly better than SF-36 (AUC = 0.705) at predicting PCMD over 6 years (P = .21); including measures at a second time point significantly improved model discrimination for predicting PCMD (all P < .001). Gait speed identified PCMD risk in older women better than the SF-36 PF did, although the results may be limited given that gait speed served as a predictor and to define the PCMD outcome. Nonetheless, monitoring trajectories of change in mobility are better predictors of future mobility disability than single measures.

A Backward Walking Training Program to Improve Balance and Mobility in Acute Stroke: A Pilot Randomized Controlled Trial.

Strategies to address gait and balance deficits early poststroke are minimal. The postural and motor control requirements of Backward Walking Training (BWT) may provide benefits to improve balance and walking speed in this population. This pilot study (1) determined the feasibility of administering BWT during inpatient rehabilitation and (2) compared the effectiveness of BWT to Standing Balance Training (SBT) on walking speed, balance, and balance-related efficacy in acute stroke. Eighteen individuals 1-week poststroke were randomized to eight, 30-minute sessions of BWT or SBT in addition to scheduled therapy. Five-Meter Walk Test, 3-Meter Backward Walk Test, Activities-Specific Balance Confidence Scale, Berg Balance Scale, Sensory Organization Test, and Function Independence Measure-Mobility were assessed pre- and postintervention and at 3 months poststroke. Forward gait speed change (BWT: 0.75 m/s; SBT: 0.41 m/s), assessed by the 5-Meter Walk Test, and backward gait speed change (BWT: 0.53 m/s; SBT: 0.23 m/s), assessed by the 3-Meter Backward Walk Test, preintervention to 1-month retention were greater for BWT than for SBT (P < 0.05). Group difference effect size from preintervention to 1-month retention was large for Activities-Specific Balance Confidence Scale, moderate for Berg Balance Scale and Function Independence Measure-Mobility, and small for Sensory Organization Test. Individuals 1-week poststroke tolerated 30 min/d of additional therapy. At 1-month postintervention, BWT resulted in greater improvements in both forward and backward walking speed than SBT. Backward walking training is a feasible important addition to acute stroke rehabilitation. Future areas of inquiry should examine BWT as a preventative modality for future fall incidence.Video Abstract available for more insights from the authors (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A193).

Gait Analyses in Mice: Effects of Age and Glutathione Deficiency.

Minor changes (~0.1 m/s) in human gait speed are predictive of various measures of decline and can be used to identify at-risk individuals prior to further decline. These associations are possible due to an abundance of human clinical research. However, age-related gait changes are not well defined in rodents, even though rodents are used as the primary pre-clinical model for many disease states as well as aging research. Our study investigated the usefulness of a novel automated system, the CatWalk™ XT, to measure age-related differences in gait. Furthermore, age-related functional declines have been associated with decreases in the reduced to oxidized glutathione ratio leading to a pro-oxidizing cellular shift. Therefore the secondary aim of this study was to determine whether chronic glutathione deficiency led to exacerbated age-associated impairments. Groups of male and female wild-type (gclm+/+) and knock-out (gclm-/-) mice aged 4, 10 and 17 months were tested on the CatWalk and gait measurements recorded. Similar age-related declines in all measures of gait were observed in both males and females, and chronic glutathione depletion was associated with some delays in age-related declines, which were further exacerbated. In conclusion, the CatWalk is a useful tool to assess gait changes with age, and further studies will be required to identify the potential compensating mechanisms underlying the effects observed with the chronic glutathione depletion.

What factors determine the preferred gait transition speed in humans? A review of the triggering mechanisms

Human locomotion is a fundamental skill that is required for daily living, yet it is not completely known how human gait is regulated in a manner that seems so effortless. Gait transitions have been analyzed to gain insight into the control mechanisms of human locomotion since there is a known change that occurs as the speed of locomotion changes. Specifically, as gait speed changes, there is a spontaneous transition between walking and running that occurs at a particular speed. Despite the growing body of research on the determinants of this preferred transition speed and thus the triggering mechanisms of human gait transitions, a clear consensus regarding the control mechanisms of gait is still lacking. Therefore, this article reviews the determinants of the preferred transition speed using concepts of the dynamic systems theory and how these determinants contribute to four proposed triggers (i.e. metabolic efficiency, mechanical efficiency, mechanical load and cognitive and perceptual) of human gait transitions. While individual anthropometric and strength characteristics influence the preferred transition speed, they do not act to trigger a gait transition. The research has more strongly supported the mechanical efficiency and mechanical load determinants as triggering mechanisms of human gait transitions. These mechanical determinants, combined with cognitive and perceptual processes may thus be used to regulate human gait patterns through proprioceptive and perceptual feedback as the speed of locomotion changes.

Cardiac Rehabilitation Leads to Improvements in Activity Limitations.

The purposes of this study were to identify the number of participants who enter cardiac rehabilitation with an activity limitation and assess whether a cardiac rehabilitation program leads to improvements in activity, demonstrated through changes in gait speed and the 5-times-sit-to-stand test (FTSST). This study utilized a 1-group pretest-posttest design. Gait speed and FTSST were measured at the start and end of cardiac rehabilitation. Paired sample t tests were performed to assess changes pre- and postrehabilitation. Subgroup analysis was done on patients who presented with an activity limitation on admission (gait speed <1.0 m/s or FTSST time >12 seconds) to determine whether this subgroup experienced greater changes. On admission, 60.2% of participants presented with an activity limitation using FTSST as the criterion. At the completion of cardiac rehabilitation, participants demonstrated improvements in gait speed and FTSST, but improvements were less than the minimal detectable change (MDC) for the outcome measures. Those who presented with an activity limitation on admission had greater improvements and surpassed the MDC. Even after cardiac rehabilitation, more than 30% of participants still had an activity limitation. Patients entering cardiac rehabilitation present with activity limitations and most, but not all, will make gains through a standard course of cardiac rehabilitation. Clinicians and researchers should consider how cardiac rehabilitation programs can be modified to assess the presence of activity limitation and maximize improvements in function to enhance participation in society.

Slow gait speed after bilateral total knee arthroplasty is associated with suboptimal improvement of knee biomechanics

The aim of this study was to investigate gait speed changes 2years after bilateral total knee arthroplasty (TKA) and identify kinetic and kinematic factors associated with such changes by comparing patients with age- and sex-matched controls. The study group included 34 female patients with end-stage knee osteoarthritis (OA) who underwent bilateral TKA and 42 age- and sex-matched controls without knee pain or OA. Standard TKA was performed on all arthritic patients with placement of posterior stabilized fixed-bearing implants. Kinetic and kinematic parameters were evaluated using a commercial optoelectric gait analysis system. Gait speed, kinetic and kinematic changes and determinants of speed were assessed via principal component analysis and multiple regression analysis. The average gait speed of an arthritic patient was 90.2±18.4cm/s and improved to 96.0±12.3cm/s after TKA (p=0.032). However, the speed remained slower than that of controls (111.2±8.2cm/s, p<0.001). With regard to kinetics, the peak knee extension moment (KEM) generated by the quadriceps was unchanged after TKA and weaker than that of controls (p<0.001). The proportions of KEM contributing to the total sagittal moment were also smaller in the pre-/post-operative groups than in the control group (13-14% vs. 19%). On the other hand, the ankle plantar flexion moment (APFM) was increased after TKA (p=0.007) and its proportion of the total sagittal moment was greater than in controls (46% vs. 42%). With regard to kinematics, knee range of motion (ROM) improved after TKA (p=0.025), but was smaller than that of controls (p<0.001). In controls, gait speed was determined principally by hip and knee joint moments. However, in the TKA group, speed was determined by the knee ROM and APFM. Despite showing improvement, the gait speed of TKA patients remained slower than that of controls. Slow gait speed after bilateral TKA was associated with suboptimal improvement of knee biomechanics. Quadriceps strengthening exercises and the achievement of greater ROM during gait are advised for the further improvement of gait speed. Retrospective cohort study, Level III.

The effect of working memory intervention on the gait patterns of the elderly

IntroductionThe purpose of this study was to evaluate the role of working memory (WM) training on walking patterns in elderly people. Methods20 elderly adults were selected and assigned randomly to two groups: WM training group and control group. WM training group received 6 weeks of computerized training on various spatial and verbal WM tasks. The spatial-temporal parameters, the ground reaction force and the timing activity of muscles in pre-posttest and in a follow-up were taken. ResultThe results indicated that a significant change in gait speed, double support time and stride time (p < 0.05). Alternations in ground reaction force (GRF) components were found significant. Timing of muscle activity also showed non-significant change after WM intervention. ConclusionBased on the results of this study, it can be concluded that WM intervention can be applied to improve gait parameters. The improvements in vertical ground reaction force after training may result in an increase upright stability and a decreased in rate falls.

Dose of physical activity, physical functioning and disability risk in mobility-limited older adults: Results from the LIFE study randomized trial.

Understanding the minimal dose of physical activity required to achieve improvement in physical functioning and reductions in disability risk is necessary to inform public health recommendations. To examine the effect of physical activity dose on changes in physical functioning and the onset of major mobility disability in The Lifestyle Interventions and Independence for Elders (LIFE) Study. We conducted a multicenter single masked randomized controlled trial that enrolled participants in 2010 and 2011 and followed them for an average of 2.6 years. 1,635 sedentary men and women aged 70–89 years who had functional limitations were randomized to a structured moderate intensity walking, resistance, and flexibility physical activity program or a health education program. Physical activity dose was assessed by 7-day accelerometry and self-report at baseline and 24 months. Outcomes included the 400 m walk gait speed, the Short Physical Performance Battery (SPPB), assessed at baseline, 6, 12, and 24 months, and onset of major mobility disability (objectively defined by loss of ability to walk 400 m in 15 min). When the physical activity arm or the entire sample were stratified by change in physical activity from baseline to 24 months, there was a dose-dependent increase in the change in gait speed and SPPB from baseline at 6, 12, and 24 months. In addition, the magnitude of change in physical activity over 24 months was related to the reduction in the onset of major mobility disability (overall P < 0.001) (highest versus the lowest quartile of physical activity change HR 0.23 ((95% CI:0.10–0.52) P = 0.001) in the physical activity arm. We observed a dose-dependent effect of objectively monitored physical activity on physical functioning and onset of major mobility disability. Relatively small increases (> 48 minutes per week) in regular physical activity participation had significant and clinically meaningful effects on these outcomes.Trial registration: ClinicalsTrials.gov NCT00116194

The role of movement errors in modifying spatiotemporal gait asymmetry post stroke: a randomized controlled trial

Objective: Current rehabilitation to improve gait symmetry following stroke is based on one of two competing motor learning strategies: minimizing or augmenting symmetry errors. We sought to determine which of those motor learning strategies best improves overground spatiotemporal gait symmetry. Design: Randomized controlled trial. Setting: Rehabilitation research lab. Subjects: In all, 47 participants (59 ± 12 years old) with chronic hemiparesis post stroke and spatiotemporal gait asymmetry were randomized to error augmentation, error minimization, or conventional treadmill training (control) groups. Interventions: To augment or minimize asymmetry on a step-by-step basis, we developed a responsive, “closed-loop” control system, using a split-belt instrumented treadmill that continuously adjusted the difference in belt speeds to be proportional to the patient’s current asymmetry. Main measures: Overground spatiotemporal asymmetries and gait speeds were collected prior to and following 18 training sessions. Results: Step length asymmetry reduced after training, but stance time did not. There was no group × time interaction. Gait speed improved after training, but was not affected by type of asymmetry, or group. Of those who trained to modify step length asymmetry, there was a moderately strong linear relationship between the change in step length asymmetry and the change in gait speed. Conclusion: Augmenting errors was not superior to minimizing errors or providing only verbal feedback during conventional treadmill walking. Therefore, the use of verbal feedback to target spatiotemporal asymmetry, which was common to all participants, appears to be sufficient to reduce step length asymmetry. Alterations in stance time asymmetry were not elicited in any group.

Adaptive locomotor network activation during randomized walking speeds using functional near-infrared spectroscopy.

An improved understanding of the mechanisms underlying locomotor networks has the potential to benefit the neurorehabilitation of patients with neurological locomotor deficits. However, the specific locomotor networks that mediate adaptive locomotor performance and changes in gait speed remain unknown. The aim of the present study was to examine patterns of cortical activation associated with the walking speeds of 1.5, 2.0, 2.5, and 3.0 km/h on a treadmill. Functional near-infrared spectroscopy (fNIRS) was performed on a 30-year-old right-handed healthy female subject, and cerebral hemodynamic changes were observed in cortical locomotor network areas including the primary sensorimotor cortex (SMC), premotor cortex (PMC), supplementary motor area (SMA), prefrontal cortex (PFC), and sensory association cortex (SAC). The software package NIRS-statistical parametric mapping (NIRS-SPM) was utilized to analyze fNIRS data in the MATLAB environment. SPM t-statistic maps were computed at an uncorrected threshold of p< 0.00001. At faster walking speeds, oxygenated hemoglobin (OxyHb) was concentrated in the PFC and indicated globalized locomotor network activation of the SMC, PMC, SMA, and PMC; additionally, the site with the highest cortical activation ratio shifted from the SMC to the SMA. Global locomotor network recruitment, in particular PFC activation indicated by OxyHb in our study, may indicate a response to increased cognitive-locomotor demand due to simultaneous postural maintenance and leg movement coordination.

Handgrip strength is associated with, but poorly predicts, disability in older women with acute low back pain: A 12-month follow-up study

BackgroundOlder women with low back pain (LBP) constitute a special subpopulation at risk of severe and permanent disability. It is important to identify factors limiting functionality in this population in order to reduce costs and improve both prevention and intervention. Handgrip strength (HGS) is a biomarker of aging associated with several adverse health outcomes, but long-term associations with disability in older patients with LBP are not known. ObjectiveTo examine whether HGS predicts disability in older women with acute low back pain (LBP). MethodsLongitudinal analyses were conducted with a sample of 135 older women from the international multicenter study Back Complaints in the Elders (BACE-Brazil). Women aged 60 years and over with a new episode of acute LBP were included. HGS was assessed with Jamar® dynamometer, and disability was assessed using the Roland Morris questionnaire and gait speed test. Variables were assessed at baseline and at 12-month follow-up. Linear regression models explored associations between HGS and disability measures. ResultsSignificant association was found between HGS at baseline and gait speed at 12-month follow-up (r=−0.24; p=0.004). A multivariable-adjusted model showed that this association was independent of age, body mass index, and pain intensity (adjusted R2=0.13; p<0.001). A final prediction model showed an incremental difference of only 2.1% in gait speed after inclusion of HGS as an independent variable. No association was found between HGS and score on the Roland Morris questionnaire. ConclusionCaution is needed regarding the use of HGS as a predictive measure of disability in older women with acute LBP. Changes in gait speed were very small and unlikely to be of clinical relevance.

Catechol-O-Methyltransferase Genotype and Gait Speed Changes over 10 Years in Older Adults.

To determine the association between catechol-O-methyltransferase (COMT) genotype and 6-m walk time and to determine whether these associations are quadratic in nature, similar to previously reported U-shaped associations between dopamine and gait and cognition. Prospective cohort study. Health, Aging and Body Composition Study. Black (n = 850) and white (n = 1,352) men and women with a mean age of 73.5 ± 2.85 at baseline. Mixed models were used to assess the association between the COMT genotype and 6-m walk time, cross-sectionally and longitudinally over 10 years. Models were assessed unstratified and stratified according to race because allele distributions were different between white and black participants. There was a significant U-shaped association between COMT genotype and 6-m walk time: those with higher (Val/Val) and lower (Met/Met) dopamine slowed more over 10 years (0.22 ± 0.02 seconds per visit and 0.23 ± 0.02 seconds per visit, respectively) than those with the intermediate (Met/Val) dopamine (0.20 ± 0.02 seconds per visit) (P = .005). Stratified results showed a significant relationship in black (P = .01) but not white (P = .15) participants. These findings indicate a role of dopaminergic regulation of gait speed in community-dwelling older adults and of prefrontal cortex involvement in gait performance. Future work should investigate the molecular integrity of dopaminergic networks and gait changes over time and structural changes in the brain with COMT and gait decline in older adults.

Effects of application of texture insoles on the balance of subjects with Multiple Sclerosis

Objective: The aim of this study was to evaluate the effects on static and dynamic balance after the use of textured insoles. Method: Fifteen subjects with multiple sclerosis were evaluated before using the insoles, after using them for 1 month, and after 2 months without using, them using the following measuring instruments: the Berg Balance Scale, Dynamic Gait Index, and 10-meter Walk Test, a means of functional gait assessment. Results: Improvement was observed in the Berg Balance Scale and Dynamic Gait Index scores, walking time, number of steps and step length after using the insoles for 1 month. The improvement in Berg Balance Scale score remained after two months without the insoles and there were no changes in gait speed. Conclusion: The use of textured insoles was effective as an intervention to improve static and dynamic balance in patients with multiple sclerosis.

Lap Time Variation Predicts Task Error During Dual-Task Walking In Cognitively Healthy Women

Variation in lap time (LTV) during a fast pace 400m walk test is a new metric thought to be an early indicator of cognitive decline in older adults. While LTV has been found to associate with executive function, no study has examined the potential for LTV to predict capacity of the brain to divide attention and meet the demand of walking and performing other tasks simultaneously. PURPOSE: The purpose of this study was to test the hypothesis that greater LTV would associate with larger dual-task cost during walking. METHODS: Fifty-two cognitively healthy (MoCA>25) women across a broad age range (30-80y) performed fast pace walking while balancing a tray (Dual1) or balancing a tray while vocalizing serial subtractions by 7’s (Dual2). Task error was quantified by degrees of tray tilt and subtraction error. On a separate day, women completed a fast pace 400m walk test (40m x 10 laps) with time to complete each lap recorded. LTV was defined as standard deviation of residuals estimated from the random effects linear model where each lap time was regressed on a person-specific random intercept and random slope associated with lap. Women were categorized into tertiles based on LTV. Comparisons were made between tertiles using ANCOVA after adjusting for age, years of education, and mean lap time. RESULTS: Gait speed (p=0.57) or the percent change in gait speed (p=0.34) were not significantly different between tertiles for the Dual1 condition, but tilt angle was larger in women with greater LTV (tertiles 1 vs. 3: 1.37±0.12 vs. 1.94±0.11 degrees; p=0.006). During the Dual2 condition, women with greater LTV had faster gait speed (p=0.02), lower percent change in gait speed (tertiles 1 vs. 3: 20.5±2.8 vs. 9.3±2.6%, p=0.02), similar subtraction error (p=0.58), but larger tilt angle (tertiles 1 vs. 3: 1.24±0.19 vs. 2.09±0.17 degrees, p=0.007). CONCLUSION: Lap time variation identified women that exhibited greater difficulty balancing an object while walking suggesting that LTV may be sensitive to deficits in the ability to share neural substrate for sensorimotor function. Supported by a Women’s Health Research Scholar Grant award from the Laura W. Bush Institute of Women’s Health and University Medical Center in Lubbock, TX.

Cerebellar theta burst stimulation does not improve freezing of gait in patients with Parkinson\u2019s disease

Freezing of gait (FOG) in Parkinson’s disease (PD) likely results from dysfunction within a complex neural gait circuitry involving multiple brain regions. Herein, cerebellar activity is increased in patients compared to healthy subjects. This cerebellar involvement has been proposed to be compensatory. We hypothesized that patients with FOG would have a reduced ability to recruit the cerebellum to compensate for dysfunction in other brain areas. In this study cerebellar activity was modified unilaterally by either excitatory or inhibitory theta burst stimulation (TBS), applied during two separate sessions. The ipsilateral cerebellar hemisphere, corresponding to the body side most affected by PD, was stimulated. Seventeen patients with PD showing ‘off’ state FOG participated. The presence of FOG was verified objectively upon inclusion. We monitored gait and bimanual rhythmic upper limb movements before and directly after TBS. Gait was evaluated with a FOG-provoking protocol, including rapid 360° turns and a 10-m walking test with small fast steps. Upper limb movement performance was evaluated with a repetitive finger flexion–extension task. TBS did not affect the amount of freezing during walking or finger tapping. However, TBS did increase gait speed when walking with small steps, and decreased gait speed when walking as fast as possible with a normal step size. The changes in gait speed were not accompanied by changes in corticospinal excitability of M1. Unilateral cerebellar TBS did not improve FOG. However, changes in gait speed were found which suggests a role of the cerebellum in PD.

Carotid flow pulsatility is higher in women with greater decrement in gait speed during multi-tasking

AimCentral arterial hemodynamics is associated with cognitive impairment. Reductions in gait speed during walking while performing concurrent tasks known as dual-tasking (DT) or multi-tasking (MT) is thought to reflect the cognitive cost that exceeds neural capacity to share resources. We hypothesized that central vascular function would associate with decrements in gait speed during DT or MT. MethodsGait speed was measured using a motion capture system in 56 women (30–80y) without mild-cognitive impairment. Dual-tasking was considered walking at a fast-pace while balancing a tray. Multi-tasking was the DT condition plus subtracting by serial 7′s. Applanation tonometry was used for measurement of aortic stiffness and central pulse pressure. Doppler-ultrasound was used to measure blood flow velocity and β-stiffness index in the common carotid artery. ResultsThe percent change in gait speed was larger for MT than DT (14.1±11.2 vs. 8.7±9.6%, p <0.01). Tertiles were formed based on the percent change in gait speed for each condition. No vascular parameters differed across tertiles for DT. In contrast, carotid flow pulsatility (1.85±0.43 vs. 1.47±0.42, p=0.02) and resistance (0.75±0.07 vs. 0.68±0.07, p=0.01) indices were higher in women with more decrement (third tertile) as compared to women with less decrement (first tertile) in gait speed during MT after adjusting for age, gait speed, and task error. Carotid pulse pressure and β-stiffness did not contribute to these tertile differences. ConclusionElevated carotid flow pulsatility and resistance are characteristics found in healthy women that show lower cognitive capacity to walk and perform multiple concurrent tasks.

Circulating MiRNAs as biomarkers of gait speed responses to aerobic exercise training in obese older adults.

Gait speed is a useful predictor of adverse outcomes, including incident mobility disability and mortality in older adults. While aerobic exercise training (AEX) is generally an effective therapy to improve gait speed, individual responses are highly variable. Circulating microRNAs (miRNAs) may contribute to inter-individual changes in gait speed with AEX. We examined whether plasma miRNAs are associated with gait speed changes (dGaitSp) in 33 obese older adults (age: 69.3±3.6 years, BMI: 34.0±3.1 kg/m2, 85% white, 73% women) who performed treadmill walking, 4 days/week for 5 months. Gait speed (baseline: 1.02±0.19 m/s; range of response: −0.2 to 0.35 m/s) was assessed using a 400 meter-fast-paced walk test. Using Nanostring technology, 120 out of 800 miRNAs were found to be abundantly expressed in plasma and 4 of these were significantly changed after AEX: miR-376a-5p increased, while miR-16-5p, miR-27a-3p, and miR-28-3p all decreased. In addition, baseline miR-181a-5p levels (r=-0.40, p=0.02) and percent changes in miR-92a-3p (r=-0.44, p=0.009) associated negatively with dGaitSp. Linear regression combined baseline miR-181a-5p and miR-92a-3p levels showed even stronger associations with dGaitSp (r=-0.48, p=0.005). These results suggest that circulating miR-181a-5p and miR-92a-3p may predict and/or regulate AEX-induced gait speed changes in obese older adults.