Walking Performance In People Research Articles

Influence of Verbal Instruction on Gait Training in Parkinson Disease: A Randomized Controlled Trial.

Verbal instruction is one of the most commonly used methods that therapists use to correct walking pattern for people with Parkinson disease. This study aimed to compare the long-term training effects of two different verbal instructions that either asked the participants to "take big steps" or "strike the ground with the heel" on walking ability in individuals with Parkinson disease. Forty-five participants with Parkinson disease were randomized into the big-step or heel strike group. The participants underwent 12 sessions of treadmill and overground gait training. Throughout the interventions, the big-step group received an instruction to "take big steps," while the heel strike group received an instruction to "strike the ground with your heel." The primary outcome was gait performance, including velocity, stride length, cadence, and heel strike angle. The participants were assessed before, immediately after, and 1 mo after training. Both groups showed significant improvements in gait performance after training. The heel strike group showed continuous improvements in velocity and stride length during the follow-up period; however, the big-step group showed slightly decreased performance. A verbal instruction emphasizing heel strike can facilitate long-term retention of walking performance in people with Parkinson disease.

Abstract 15871: Clinical Characteristics Associated With Response to Exercise and Serious Adverse Events During Home-Based Walking Exercise in People With Lower Extremity Peripheral Artery Disease

Background: Home-based walking exercise improves walking performance in people with lower extremity peripheral artery disease (PAD). However, whether clinical and sociodemographic factors, such as age, sex, race, comorbidities, and income, are associated with response to exercise or rates of serious adverse events (SAEs) during a home-based walking exercise intervention for PAD is unclear. Methods: Data from participants randomized to two clinical trials of home-based walking exercise for PAD were pooled. Both clinical trials used behavioral methods to help participants adhere to walking exercise up to 5 days/week for up to 50 minutes/session for 6-months. Outcomes were change in six-minute walk (6MW) at 6-months and rates of SAEs at 12-months. SAEs were defined as death or hospitalization. Results: 325 unique participants [mean age 69.8 (9.1), 161 (49.5%) female, 182 (56.0%) Black] had available 6MW and SAE data. Home-based walking exercise improved 6MW distance, compared to control, at 6-month follow-up [mean: +46.4 meters (95% CI: +31.5 meters, 61.2 meters)]. The effect of home-based exercise on 6MW was similar across clinical and sociodemographic characteristics. 51 (27.3%) participants reported SAEs in the home-based exercise group and 32 (23.2%) reported SAEs in the control group (p=0.40). Among those randomized to home-based walking exercise, odds of SAE were significantly higher among Black compared to White participants, those with history of coronary artery disease (CAD) and heart failure (HF) compared to those without (Figure). Statistically significant interactions were identified between Black race (P<0.001), coronary artery disease (P=0.006) and lower income zipcodes (P=0.047) and the effect of exercise on rates of SAEs. Conclusion: In people with PAD randomized to home-based exercise, those who were Black, had a history of CAD or HF were significantly more likely to experience SAEs, compared to people without these characteristics.

Ankle dorsiflexion asymmetry and the relationship with walking performance in people with multiple sclerosis

BackgroundMultiple sclerosis (MS) is a neurological disease characterized by demyelination disrupting the central nervous system. Persons with MS may exhibit symptomatic strength asymmetry (SA) that impacts motor gait and ankle mobility. The purpose of the present study was to investigate ankle dorsiflexion SA in people with MS and its relationship to functional performance. Research QuestionIs their a difference in dorsiflexion SA in MS participants compared to healthy individuals and does it impact functional performance? Methods13 MS participants (EDSS 3.5 + 1.8) and 13 age matched NON-MS participants underwent maximal isometric (MVC) dynamometry testing for ankle dorsiflexion in both limbs to determine SA. Participants performed three functional tasks of walking performance. ResultsThere was a significant intra-limb MVC difference in the MS group, and significantly greater isometric SA (p < 0.007) and isokinetic SA (p < 0.04) in the MS group compared to healthy individuals. The MS group exhibited significant correlations between outcomes of functional walking performance with isokinetic but not isometric SA. There was no significant correlation between disability status and functional task performance. SignificanceAnkle dorsiflexion SA is negatively correlated with functional performance in MS participants. MS disability status was not a predictor of functional task performance, and symptom testing may be appropriate to assess walking ability in persons with MS.

Study Design, Rationale, and Methodology for Promote Weight Loss in Patients With Peripheral Artery Disease Who Also Have Obesity: The PROVE Trial.

Background Overweight and obesity are associated with adverse functional outcomes in people with peripheral artery disease (PAD). The effects of weight loss in people with overweight/obesity and PAD are unknown. Methods The PROVE (Promote Weight Loss in Obese PAD Patients to Prevent Mobility Loss) Trial is a multicentered randomized clinical trial with the primary aim of testing whether a behavioral intervention designed to help participants with PAD lose weight and walk for exercise improves 6-minute walk distance at 12-month follow-up, compared with walking exercise alone. A total of 212 participants with PAD and body mass index ≥25 kg/m2 will be randomized. Interventions are delivered using a Group Mediated Cognitive Behavioral intervention model, a smartphone application, and individual telephone coaching. The primary outcome is 12-month change in 6-minute walk distance. Secondary outcomes include total minutes of walking exercise/wk at 12-month follow-up and 12-month change in accelerometer-measured physical activity, the Walking Impairment Questionnaire distance score, and the Patient-Reported Outcomes Measurement Information System mobility questionnaire. Tertiary outcomes include 12-month changes in perceived exertional effort at the end of the 6-minute walk, diet quality, and the Short Physical Performance Battery. Exploratory outcomes include changes in gastrocnemius muscle biopsy measures of mitochondrial cytochrome C oxidase activity, mitochondrial biogenesis, capillary density, and inflammatory markers. Conclusions The PROVE randomized clinical trial will evaluate the effects of exercise with an intervention of coaching and a smartphone application designed to achieve weight loss, compared with exercise alone, on walking performance in people with PAD and overweight/obesity. Results will inform optimal treatment for the growing number of patients with PAD who have overweight/obesity. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04228978.

Association Between Frailty and Free-Living Walking Performance in People With Multiple Sclerosis.

The purpose of this study was to examine the association between frailty and the quantity and quality of free-living walking and the mediating effect of frailty on the relationship between disability and walking performance in people with multiple sclerosis (MS). Ninety-nine people with relapsing-remitting MS (mean age = 49.3 [SD = 9.8] years; 73.7% women; Expanded Disability Status Scale [EDSS] score range = 2.0-6.0) wore a triaxial accelerometer for 7days. Recorded measures reflected the quantity (daily step counts, number of 30-second walking bouts, and signal vector magnitude [SVM]) and quality (gait speed, step cadence, step and stride regularity, and sample entropy) of walking. For each walking quality measure, the typical (median), best (90th percentile), and worst (10th percentile) values were calculated. Frailty was evaluated through a 38-item frailty index. Participants were classified as not frail (n = 31), moderately frail (n = 34), and severely frail (n = 34) on the basis of established procedures. Patients who were moderately and severely frail exhibited poorer performance in all measures of walking quantity and quality, except for sample entropy, than individuals who were not frail. No differences in free-living walking performance were observed between the moderately and severely frail groups. Frailty did not mediate the relationship between disability (EDSS) and measures of walking quality. Conversely, frailty had a significant mediating effect on the relationship between disability and measures of walking quantity, such as daily step counts (indirect effect: b = -220.42, 95% CI = -452.03 to -19.65) and SVM (indirect effect: b = -1.00, 95% CI = -1.86 to -0.30). Frailty is associated with poorer free-living walking performance in people with MS. The study findings suggest that frailty, rather than disability, may be primarily responsible for the lower amount of physical activity performed by people with MS in the real world. The observation that frailty and disability are differently related to measures of walking quality and quantity underscores the importance of a targeted approach to rehabilitation in people with MS.

Abstract P626: Associations of Supervised and Home-Based Exercise With Serious Adverse Event Rates During Exercise Interventions for Peripheral Artery Disease: A Meta-Analysis of Five Randomized Clinical Trials

Background: Supervised or home-based walking exercise therapy (ET) are guideline recommended to improve walking performance in people with peripheral artery disease (PAD). This study compared serious adverse event (SAE) rates associated with home-based compared to supervised exercise in people randomized into clinical trials of ET for PAD. Methods: Data from five randomized clinical trials of ET for PAD were combined. In three trials (GOALS, HONOR, and LITE), participants were randomized to home-based ET or control. In two trials (PROPEL and TELEX), participants were randomized to supervised ET or control. The primary outcome in all trials was change in six-minute walk. SAEs consisted of hospitalization or death and were identified from participants, family members, and medical records. In post-hoc analyses, a meta-analysis compared associations of supervised ET and home-based ET on odds of a SAE or death. Control groups from the trials of supervised and home-based ET were not combined. Results: 867 unique participants were included (mean age + SD: 69 ±10 years, 47% female, 57 % Black, mean + SD ABI 0.66 ±0.15). Results are shown in the Table. Conclusion: In clinical trials of home-based ET, rates of coronary revascularizations and cardiovascular events were significantly higher in participants randomized to exercise, compared to control. However, there were no significant differences in rates of coronary revascularizations or cardiovascular events between participants randomized to home-based, compared to supervised ET. Improved walking performance from home-based exercise may precipitate symptoms from underlying coronary artery disease in people with PAD.

A case series on the effectiveness of the ReAktiv PDE Orthosis following high-energy ankle trauma

In this presentation I aim to highlight the effectiveness of the ReAktiv PDE orthosis to improve physical function in people who have sustained lower extremity injuries during high-energy trauma (HET). These injuries often require complex surgery and extensive rehabilitation, resulting in long-term problems such as pain, loss of function and limitations in physical activity. There is limited evidence in the literature on the success of passive-dynamic ankle-foot-orthosis being used for unloading traumatic ankle injuries and improving physical function in general populations as previous studies have predominantly been conducted on military personnel. For this study, a case series was used to evaluate the effect the ReAktiv PDE Orthosis and a six-week rehabilitation program had on physical function in people with a HET injury. Measures of physical function were recorded pre- and post-fitting of the orthosis in three people who had sustained a HET injury to the lower limb. Physical function was assessed using the Lower Extremity Functional Score (LEFS), Two-minute walk test (2MWT), Single-Leg Balance (SLB), Timed stair ascent (TSA), and the Four-square step test (FSST). Following wearing of the orthosis and the completion of the rehabilitation programme, lower limb function improved in two of the participants. These improvements in physical function were seen as indicated by the change in scores seen in the 2MWT, FSST, TSA and the SLB test at the commencement and conclusion of the rehabilitation programme. The ReAktiv PDE orthosis shows potential as a treatment option to improve walking performance in people who have sustained a lower extremity HET injury. In addition to the use of the orthosis, the use of a six-week physiotherapy-led rehabilitation programme, recorded further improvements in physical function specifically walking performance, physical mobility, and balance.

Abstract 11480: Telmisartan to Improve Walking Performance in People With Lower Extremity Peripheral Artery Disease: The Telex Randomized Clinical Trial

BACKGROUND. People with lower extremity peripheral artery disease (PAD) have reduced lower extremity perfusion, impaired lower extremity skeletal muscle function, and poor walking performance. Telmisartan, an angiotensin receptor blocker (ARB), has properties that reverse these abnormalities. This randomized clinical trial tested whether telmisartan improved six-minute walk distance, compared to placebo, in people with PAD at 6-month follow-up. METHODS. This multi-centered randomized clinical trial was designed as a 2 x 2 factorial design, comparing the effects of telmisartan plus supervised exercise therapy (SET) to telmisartan alone and SET alone, respectively and comparing telmisartan alone to placebo. PAD participants were randomized to one of four groups: telmisartan+SET (N=30), telmisartan + attention control (N=29), placebo + SET (N=28), or placebo+ attention control (N=27) for six months. Due to slower than anticipated enrollment, the primary comparison was changed to a comparison of the two telmisartan groups combined to the two placebo groups combined. The primary outcome was 6-month change in 6-minute walk distance. Secondary outcomes were maximal treadmill walking distance, the Walking Impairment Questionnaire distance, speed, and stair climbing scores, and the short-form 36 physical functioning score. Results adjusted for site, baseline six-minute walk distance, randomization to SET vs. attention control, and group differences in the prevalence of sex and heart failure at baseline. RESULTS. Of 114 randomized patients (mean [SD] age, 67.3 [9.9] years, 46 (40.4%) female, 81 (71.1%) Black), 105 (92%) completed 6-month follow-up. See the Table for results. CONCLUSIONS. These results do not support telmisartan for improving objectively measured walking performance or patient reported outcomes in patients with PAD.

Neural correlates of dual-task walking in people with central neurological disorders: a systematic review.

People with central neurological disorders experience difficulties with dual-task walking due to disease-related impairments. The objective of this review was to provide a comprehensive examination of the neural correlates (structural/functional brain changes) of dual-task walking in people with Parkinson's disease (PD), multiple sclerosis (MS), stroke, and Alzheimer's disease (AD). A systematic review of the literature was conducted, following PRISMA guidelines, on Medline, Embase, and Scopus. Included studies examined the relationship between structural and functional brain imaging and dual-task walking performance in people with PD, MS, stroke, and AD. Articles that met the inclusion criteria had baseline characteristics, study design, and behavioral and brain outcomes extracted. Twenty-three studies were included in this review. Most structural imaging studies (75%) found an association between decreased brain integrity and poor dual-task performance. Specific brain regions that showed this association include the striatum regions and hippocampus in PD and supplementary motor area in MS. Functional imaging studies reported an association between increased prefrontal activity and maintained (compensatory recruitment) or decreased dual-task walking performance in PD and stroke. A subset (n = 2) of the stroke papers found no significant correlations. Increased supplementary motor area activity was associated with decreased performance in MS and stroke. No studies on AD were identified. In people with PD, MS, and stroke, several neural correlates of dual-task walking have been identified, however, the direction of the association between neural and performance outcomes varied across the studies. The type of cognitive task used and presentation modality (e.g., visual) may have contributed to these mixed findings.

Ankle Dorsiflexion Asymmetry and the Relationship with Walking Performance in People with Multiple Sclerosis

Ankle Dorsiflexion Asymmetry and the Relationship with Walking Performance in People with Multiple Sclerosis

Effects of supervised exercise therapy on blood pressure and heart rate during exercise, and associations with improved walking performance in peripheral artery disease: Results of a randomized clinical trial

ObjectiveSupervised exercise therapy (SET) improves walking ability in people with peripheral artery disease (PAD). However, the effects of SET on cardiovascular health in PAD remain unclear. Using data from a randomized clinical trial, this post hoc analyses investigated the effects of a 6-month SET intervention, compared with a control group, on changes in blood pressure (BP) and heart rate (HR) during a graded treadmill exercise test in people with PAD. MethodsWe randomized 210 participants with PAD to either SET (3× weekly) or control (1× weekly health lectures) for 6 months. A graded treadmill exercise test, 6-minute walk test, and Walking Impairment Questionnaire were completed at baseline and the 6-month follow-up. BP and HR were measured at the end of each 2-minute stage of the graded treadmill exercise test. Mixed effects regression models compared the overall mean 6-month change in systolic BP, diastolic BP, pulse pressure (PP), and HR during the first 5 stages of the graded treadmill exercise test between groups. ResultsOf the 210 randomized participants with PAD, 176 (67 ± 9 years; 72 [41%] female, 115 [65%] Black) completed the graded treadmill exercise test at baseline and the 6-month follow-up. Compared with the control group at the 6-month follow-up, SET significantly decreased overall mean systolic BP (–12 mm Hg; P < .001), PP (–9 mm Hg; P < .001), and HR (–7 b/min; P < .01) during a graded treadmill exercise test but not diastolic BP. Among participants randomized to SET, a greater decrease in systolic BP, PP, and HR during a graded treadmill exercise test was significantly associated with a greater improvement in 6-minute walk distance (systolic BP, r = –0.19 [P = .03] and PP, r = –0.23 [P < .01]; and HR, r = –0.21 [P < .01]) and with maximal treadmill walking distance (systolic BP, r = –0.21 [P < .01] and PP, r = –0.17 [P = .03]) at the 6-month follow-up. A greater decrease in the HR during a graded treadmill exercise test was significantly associated with a better WIQ distance score (r = –0.27; P = .03) at the 6-month follow-up. ConclusionsIn people with PAD, compared with a control group, SET improved cardiovascular health, measured by changes in BP and HR during exercise. The degree of improvement in cardiovascular health correlated with the degree of improvement in walking performance in people with PAD. NCT: 01408901.

Skeletal Muscle Pathology in Peripheral Artery Disease: A Brief Review.

This brief review summarizes current evidence regarding lower extremity peripheral artery disease (PAD) and lower extremity skeletal muscle pathology. Lower extremity ischemia is associated with reduced calf skeletal muscle area and increased calf muscle fat infiltration and fibrosis on computed tomography or magnetic resonance imaging. Even within the same individual, the leg with more severe ischemia has more adverse calf muscle characteristics than the leg with less severe ischemia. More adverse computed tomography-measured calf muscle characteristics, such as reduced calf muscle density, are associated with higher rates of mobility loss in people with PAD. Calf muscle in people with PAD may also have reduced mitochondrial activity compared with those without PAD, although evidence is inconsistent. Muscle biopsy document increased oxidative stress in PAD. Reduced calf muscle perfusion, impaired mitochondrial activity, and smaller myofibers are associated with greater walking impairment in PAD. Preliminary evidence suggests that calf muscle pathology in PAD may be reversible. In a small uncontrolled trial, revascularization improved both the ankle-brachial index and mitochondrial activity, measured by calf muscle phosphocreatine recovery time. A pilot clinical trial showed that cocoa flavanols increased measures of myofiber health, mitochondrial activity, and capillary density while simultaneously improving 6-minute walk distance in PAD. Calf muscle pathological changes are associated with impaired walking performance in people with PAD, and interventions that both increase calf perfusion and improve calf muscle health are promising therapies to improve walking performance in PAD.

Mitochondrial DNA damage in calf skeletal muscle and walking performance in people with peripheral artery disease

BackgroundPeripheral artery disease (PAD) is associated with mitochondrial dysfunction in calf skeletal muscle and a greater abundance of mitochondrial DNA (mtDNA) heteroplasmy. However, it is unknown whether calf skeletal muscle mtDNA of PAD participants harbors a greater abundance of mitochondrial DNA 4977-bp common deletion (mtDNA4977), strand breaks and oxidative damage (i.e., oxidized purines) compared to non-PAD participants and whether these mtDNA abnormalities are associated with poor walking performance in participants with PAD. MethodsCalf muscle biopsies were obtained from 50 PAD participants (ankle-brachial index (ABI) < 0.95) and 25 non-PAD participants (ABI = 0.99–1.40) matched by age, sex, and race. The abundance of mtDNA copy number, mtDNA4977 deletion, strand breaks, and oxidized purines in selected mtDNA regions coding for electron transport chain (ETC) constituents and the non-coding D-Loop region was determined in calf muscle. All participants completed measurement of 6-min walk and usual and fast-paced 4-m walking velocity test. ResultsParticipants with PAD (mean age = 65.4 years, SD = 6.9; 14 (28%) women, 38 (76%) black) and without PAD (mean age = 65.2 years, SD = 6.7; 7 (28%) women, 16 (64%) black) did not differ in the abundance of calf muscle mtDNA4977 deletion, mtDNA strand breaks, and oxidized purines. Though, a greater abundance of mtDNA strand breaks within ND4/5 genes was significantly associated with poorer 6-min walk distance, lower usual-paced 4-m walking velocity, and lower fast-paced 4-m walking velocity in non-PAD participants. Significant associations were also found in the density of strand break damage (i.e., damage per mtDNA copy) within ND1/2, ND4/5 and COII/ATPase 6/8 region with 6-min walk distance, usual-paced 4-m walking velocity and fast-paced 4-m walking velocity in non-PAD participants. Significant interactions were found between PAD presence vs. absence and density of strand break damage within ND1/2, ND4/5, COII/ATPase 6/8 regions for the associations with 6-min walk distance, usual-paced 4-m walking velocity, fast-paced 4-m walking velocity. Conversely, of the three walking performance measures only the usual-paced 4-m walking velocity showed a significant, although modest, negative association with the abundance of oxidized purines in the D-Loop (P = 0.031) and ND4/5 (P = 0.033) regions in the calf skeletal muscle of people with PAD. ConclusionOverall, these data suggest that the abundance of calf muscle mtDNA strand breaks and mtDNA4977 common deletion are not associated with walking performance in people with PAD and may not be directly involved in the pathophysiology of PAD. Conversely, strand breaks in specific mtDNA regions may contribute to poor walking performance in people without PAD. Further study is needed to confirm whether usual-paced 4-m walking velocity is associated significantly with a greater abundance of oxidized purines in the D-loop, a “mutational hotspot” for oxidative damage, and why this association may differ from the association with 6-min walk distance and fast-paced 4-m walking velocity.

Associations of Poly (ADP-Ribose) Polymerase1 abundance in calf skeletal muscle with walking performance in peripheral artery disease.

This study investigated associations of markers of oxidative stress and mitochondrial function in calf muscle biopsies with walking performance in people with and without lower extremity peripheral artery disease (PAD). Participants with PAD (ankle-brachial index (ABI) <0.90) and without PAD (ABI: 0.90-1.50) underwent calf muscle biopsy and measurement of 6-min walk and four-meter walking velocity. PARP1 (Poly (ADP-Ribose) Polymerase 1), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), silent information regulator 1 (SIRT1) and 4-hydroxynonenal (4HNE) expression were measured in calf muscle using western blot. Among 15 participants with PAD mean age: 66.8years (standard deviation (SD): 6.4) and six without PAD (age: 64.4years, SD: 5.9), mean PARP1-abundance in calf muscle was 1.16±0.92AU and 0.96±0.38AU, respectively (P=0.61). Among participants with PAD after adjustment with ABI, a greater abundance of PARP1 was associated with poorer 6-min walking distance (r=-0.65, P=0.01), usual-paced 4-m walking velocity (r=-0.73, P=0.003) and slower fast-paced four-meter walking velocity (r=-0.51, P=0.07). Among participants with PAD, ABI was not associated with PARP1 abundance in calf muscle (r=0.02, P=0.93). Among participants without PAD, skeletal muscle PARP1 abundance was not significantly associated with 6-min walk distance (r=-0.58; P=0.22), usual-paced walking velocity (r=-0.26; P=0.62), or fast-paced walking velocity (r=-0.21; P=0.69), perhaps due to lack of statistical power. There were no associations of remaining calf muscle measures with walking performance. These findings are consistent with the hypothesis that calf skeletal muscle characteristics are related to walking performance, independently of severity of lower extremity arterial obstruction in people with PAD.

Clinically Assessed Walking Capacity Versus Real-World Walking Performance in People with Multiple Sclerosis.

Ecological validity is an important psychometric property when assessing function. How a person with multiple sclerosis (MS) performs in clinical settings and in natural environments can be quite different. Walking is the most frequently assessed and recommended way to maintain health in a progressive disease such as MS. The objective was to estimate the extent to which clinical tests of walking capacity differ from real-world walking performance in people with MS. Ninety-eight women and 27 men with MS were assessed using the 6-Minute Walk Test (6MWT) and wore an accelerometer for 7 consecutive days. Mean number of steps, mean number of steps at a brisk cadence or faster, and cumulative time per week spent walking at a brisk cadence or faster were regressed on 6MWT categories using quantile (median) regression. Contiguous steps were grouped into bouts of less than 5 minutes and 5 minutes or longer, and number of bouts 5 minutes or longer was regressed on 6MWT categories using a zero-inflated Poisson model. A total of 869 patient-days of accelerometer data were available. Mean total number of steps per day was greater for people with higher walking capacity (6MWT distance, ≥600 m). However, this group spent a small proportion of time walking at higher cadence bands. Compared with people with 6MWT distance of at least 600 m, people walking less than 500 m had approximately half the rate of walking bouts of 5 minutes or longer. Positive mood and fewer exercise barriers predicted more walking bouts of at least 5 minutes. Study participants with MS spent a small proportion of time walking at a health-promoting intensity.

Does disability level impact the relationship of muscle strength to walking performance in people with multiple sclerosis? a cross-sectional analysis

Background and PurposeStrength training can improve muscle weakness in people with multiple sclerosis (MS), but does not consistently improve walking. Disability level may impact the relationship of muscle weakness and walking performance in people with MS, but few studies have investigated the impact of disability on the relationship of strength and walking. The purpose of this study was to compare the relationships of strength in lower body and trunk muscles to walking performance between mild and moderate disability groups in people with MS. MethodsData from 36 participants with MS who had mild disability (Expanded Disability Status Scale - EDSS 0 to 3.5) and 36 participants who had moderate disability (EDSS 4.0 to 5.5) were analyzed. Hand-held dynamometry measured strength in eight muscle groups from the ankle, knee, hip, and trunk. Timed 25-Foot Walk (T25FW) and 6-Minute Walk Test (6MWT) measured walking speed and endurance, respectively. Pearson correlations and beta coefficients (ß) were reported for each bivariate relationship of muscle strength to T25FW and 6MWT from both mild and moderate disability groups. Linear regression was then used to compare differences in beta coefficients (Δß) between disability groups for the relationship of each muscle variable to T25FW and 6MWT. A positive Δß indicated a stronger relationship of strength to walking performance in the mild disability group, while a negative Δß favored the moderate disability group. ResultsOverall, there were stronger Pearson correlations between muscle strength variables to T25FW and 6MWT in the mild (r = 0.57 to 0.77) compared to moderate disability group (r = 0.10 to 0.54). The mild disability group had significantly greater beta coefficients for T25FW with ankle dorsiflexion (Δß = 0.67, 95%CI: 0.27–1.07), knee extension (Δß = 0.68, 95%CI: 0.28–1.08), and hip abduction (Δß = 0.77, 95%CI: 0.01–1.52); and for 6MWT with knee extension (Δß = 0.47, 95%CI: 0.06 to 0.88). Discussion and ConclusionFor people with MS, muscle strength in the lower extremity and trunk may be a more important contributor to T25FW in mild versus moderate disability, but not for 6MWT. While more studies are needed, these results may help to inform rehabilitation intervention when prioritizing strength training to improve walking.

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Relationship between lower limb coordination and walking speed after stroke: an observational study

BackgroundAlthough lower limb muscle strength is associated with walking performance in people after stroke, even when there is good strength, walking speed may remain slower than normal, perhaps due to incoordination. ObjectiveThe aim of this study was to examine the relationship between walking speed and lower limb coordination in people with good strength after stroke. MethodsAn observational study was conducted with 30 people with stroke and 30 age-matched controls. Inclusion criteria for stroke were good lower limb strength (i.e., ≥Grade 4) and walking speed at >0.6m/s without aids in bare feet (with recruitment stratified so that walking speed was evenly represented across the range). Walking performance was measured as speed during the 10-m Walk Test and distance during the 6-min Walk Test. Coordination was measured using the Lower Extremity Motor Coordination Test and reported in taps/s. ResultsStroke survivors walked at 1.00 (SD 0.26) m/s during the10-m Walk Test (64% of normal), walked 349 (SD 94) m during the 6-min Walk Test (68% of normal), and performed the Lower Extremity Motor Coordination Test at 1.20 (SD 0.34) taps/s with the affected side (64% of normal). Lower Extremity Motor Coordination Test scores for the affected side were statistically significantly correlated with walking performance in the 10-m Walk Test (r=0.42, p=0.02) and the 6-min Walk Test (r=0.50, p=0.01). ConclusionCoordination was related to walking performance, suggesting that loss of coordination may contribute to slow walking in this group of stroke survivors with good strength.Trial registration: ANZCTR12614000856617 (www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366827).

Effects of lipoic acid on walking performance, gait, and balance in secondary progressive multiple sclerosis

BackgroundGait and balance impairment is common in secondary progressive multiple sclerosis (SPMS). Lipoic acid (LA), an over-the-counter antioxidant, is effective in MS animal models and may improve walking speed, but effects on mobility are unreported. ObjectiveExamine the effects of 1200 mg daily oral dose of LA versus placebo (PLA) on gait and balance in a 2-year, randomized, double-blind pilot study. Methods134 participants were screened for eligibility before assignment to LA (n = 28) or PLA (n = 26). Included here were, 21 participants with SPMS who took LA (N = 11) or PLA (N = 10) capsules for 2 years (enrolled May 2, 2011 – August 14, 2015) and completed all tasks without the use of an assistive device. Participants completed the Timed Up and Go (TUG) and quiet standing tasks every 6 months while wearing inertial sensors (APDM Opals) to quantify mobility. ResultsLA had a medium effect on time to complete TUG at 2 years (g = 0.51; 95% CI = -0.35, 1.38). In a subset of 18 participants with less disability (EDSS < 6, no use of ambulatory device), turning time was significantly shorter with LA (p = 0.048, Δ= 0.48 s). No differences in balance metrics were found between groups. ConclusionsLA had an effect on walking performance in people with SPMS, particularly in those with lower baseline disability. Trial RegistrationLipoic Acid for Secondary Progressive Multiple Sclerosis https://clinicaltrials.gov/ct2/show/NCT01188811?term=spain+lipoic+acid&rank=1 NCT0118881.

Virtual Footprints Can Improve Walking Performance in People With Parkinson's Disease.

In Parkinson's disease (PD) self-directed movement, such as walking, is often found to be impaired while goal directed movement, such as catching a ball, stays relatively unaltered. This dichotomy is most clearly observed when sensory cueing techniques are used to deliver patterns of sound and/or light which in turn act as an external guide that improves gait performance. In this study we developed visual cues that could be presented in an immersive, interactive virtual reality (VR) environment. By controlling how the visual cues (black footprints) were presented, we created different forms of spatial and temporal information. By presenting the black footprints at a pre-specified distance apart we could recreate different step lengths (spatial cues) and by controlling when the black footprints changed color to red, we could convey information about the timing of the foot placement (temporal cues). A group of healthy controls (HC; N = 10) and a group of idiopathic PD patients (PD, N = 12) were asked to walk using visual cues that were tailored to their own gait performance [two spatial conditions (115% [N] and 130% [L] of an individual's baseline step length) and three different temporal conditions (spatial only condition [NT], 100 and 125% baseline step cadence)]. Both groups were found to be able to match their gait performance (step length and step cadence) to the information presented in all the visual cue conditions apart from the 125% step cadence conditions. In all conditions the PD group showed reduced levels of gait variability (p < 0.05) while the HC group did not decrease. For step velocity there was a significant increase in the temporal conditions, the spatial conditions and of the interaction between the two for both groups of participants (p < 0.05). The coefficient of variation of step length, cadence, and velocity were all significantly reduced for the PD group compared to the HC group. In conclusion, our results show how virtual footsteps presented in an immersive, interactive VR environment can significantly improve gait performance in participants with Parkinson's disease.