Physical fitness, walking performance, and gait in multiple sclerosis

Utilizing Aerobic Capacity Data for EDSS Score Estimation in Multiple Sclerosis: A Machine Learning Approach

The Expanded Disability Status Scale (EDSS) is the most popular method to assess disease progression and treatment effectiveness in patients with multiple sclerosis (PwMS). One of the main problems with the EDSS method is that different results can be determined by different physicians for the same patient. In this case, it is necessary to produce autonomous solutions that will increase the reliability of the EDSS, which has a decision-making role. This study proposes a machine learning approach to predict EDSS scores using aerobic capacity data from PwMS. The primary goal is to reduce potential complications resulting from incorrect scoring procedures. Cardiovascular and aerobic capacity parameters of individuals, including aerobic capacity, ventilation, respiratory frequency, heart rate, average oxygen density, load, and energy expenditure, were evaluated. These parameters were given as input to CatBoost, gradient boosting (GBM), extreme gradient boosting (XGBoost), and decision tree (DT) machine learning methods. The most significant EDSS results were determined with the XGBoost algorithm. Mean absolute error, root mean square error, mean square error, mean absolute percent error, and R square values were obtained as 0.26, 0.4, 0.26, 16, and 0.68, respectively. The XGBoost based machine learning technique was shown to be effective in predicting EDSS based on aerobic capacity and cardiovascular data in PwMS.

Study protocol: exercise training for treating major depressive disorder in multiple sclerosis

BACKGROUND

Major depressive disorder (MDD) is prevalent, yet sub-optimally treated among persons with multiple sclerosis (MS). We propose that exercise training may be a promising approach for treating depression in persons with MS who have MDD. Our primary hypothesis predicts a reduction in depression severity immediately after an exercise training intervention compared with minimal change in an attention control condition, and the reduction will be maintained during a follow-up period.

METHODS

This study involves a parallel-group, assessor-blinded RCT that examines the effect of a 4-month home-based exercise training intervention on depression severity in a sample of persons with MS who have MDD based on the MINI International Neuropsychiatric Interview. The primary outcomes of depression severity are the Patient Health Questionnaire-9 and Hamilton Depression Rating Scale. Participants (N = 146) will be recruited from within 200 miles of the University of Illinois at Chicago and randomized (1:1) into either a home-based exercise training condition or control condition with concealed allocation. The exercise training and social-contact, attention control (i.e., stretching) conditions will be delivered remotely over a 4-month period and supported through eight, 1:1 Zoom-based behavioral coaching sessions guided by social-cognitive theory and conducted by persons who are uninvolved in screening, recruitment, random assignment, and outcome assessment. We will collect outcome data at 0, 4 and 8 months using treatment-blinded assessors, and data analyses will involve intent-to-treat principles.

DISCUSSION

If successful, the proposed study will provide the first Class I evidence supporting a home-based exercise training program for treating MDD in persons with MS. This is critical as exercise training would likely have positive secondary effects on symptoms, cognition, and quality of life, and provide a powerful, behavioral approach for managing the many negative outcomes of MDD in MS. The program in the proposed research is accessible and scalable for broad treatment of depression in MS, and provides the potential for integration in the clinical management of MS.

TRIAL REGISTRATION

The trial was registered on September 10, 2021 at clinicaltrials.gov with the identifier NCT05051618. The registration occurred before we initiated recruitment on June 2, 2023.

Reliability and validity of the glittre activities of daily living test in fully ambulatory multiple sclerosis patients

BACKGROUND

Evaluation of activities of daily living (ADL) and functional exercise capacity in patients with multiple sclerosis (pwMS) is crucial in demonstrating the effectiveness of interventions.

AIMS

To investigate the reliability and validity of the Glittre ADL Test in pwMS.

METHODS

Twenty-five pwMS and 26 healthy adults were included in this methodological study. The Glittre ADL Test was applied. Six-Minute Walk Test (6MWT) and Nottingham Extended Activities of Daily Living Index (NEADL) were applied for concurrent validity. Expanded Disability Status Scale (EDSS), Fatigue Severity Scale (FSS), Mini Balance Evaluation Systems Test (Mini BESTest), Multiple Sclerosis Quality of Life Scale-54 (MSQoL-54), and Five Times Sit-to-Stand Test (5 STST) were applied for construct validity. The Glittre ADL Test was repeated after 3-6 days for test-retest reliability.

RESULTS

The test-retest reliability of the Glittre ADL Test was excellent (ICC = 0.941). There was strong correlation of the Glittre ADL Test with 6MWT (rho = - 0.710, p < 0.001), NEADL (rho = - 0.841, p < 0.001), EDSS, (rho = 0.836, p = < 0.001), Mini BESTest (rho = 0.792, p < 0.001), and 5 STST scores (rho = 0.720, p < 0.001). There was a moderate correlation between the Glittre ADL Test and the physical health sub-item score of the MSQoL-54 (rho = - 0.591, p = 0.002). No correlation was found between the Glittre ADL Test and FSS (rho = 0.348, p = 0.096). There was a difference in the Glittre ADL Test results between the pwMS and the healthy adults (p = 0.001).

CONCLUSIONS

The Glittre ADL Test has excellent reliability and strong construct and criterion validity for assessing functional exercise capacity and ADL in fully ambulatory pwMS.

TRIAL REGISTRATION

TRN: NCT04182269.

Complexity and pitfalls in maximal exercise testing for persons with multiple sclerosis

BACKGROUND AND PURPOSE

Valid measurements of cardiorespiratory fitness in persons with multiple sclerosis (pwMS) are essential during inpatient rehabilitation for a precise evaluation of the current health status, for defining appropriate exercise intensities, and for evaluation of exercise intervention studies. We aim (i) to examine the proportion of pwMS who attain the American College of Sports Medicine (ACSM) criteria for maximal effort during graded cardiopulmonary exercise testing (CPET) and (ii) to provide insight into participant characteristics that limit maximal exercise performance.

METHODS

This cross-sectional study comprises a retrospective examination of ACSM criteria for maximal effort during graded CPET of n = 380 inpatient pwMS (mean age = 48 ± 11 years, 66% female). Chi-squared or Fisher's exact tests were conducted to compare differences in the distribution of criteria achieved. Participants' characteristics were examined as potential predictors using binary logistic regression.

RESULTS

Only 60% of the overall sample attained a respiratory exchange ratio ≥ 1.10. With regard to the definition applied, only 24% or 40% of the participants achieved an oxygen consumption plateau, and 17% or 50% attained the heart rate criterion. Forty-six percent met at least two of three criteria. Disability status, gender, disease course, and body mass index were associated with the attainment of maximal effort.

CONCLUSIONS

Our findings suggest that a relevant proportion of inpatient pwMS do not attain common criteria utilized to verify maximal oxygen consumption. Identified predictors for criteria attainment can be used to create models to predict cardiorespiratory fitness and to optimize CPET protocols in restrictive groups of pwMS.

Inner Retinal Layer Changes Reflect Changes in Ambulation Score in Patients with Primary Progressive Multiple Sclerosis

The establishment of surrogate markers to detect disability progression in persons with multiple sclerosis (PwMS) is important to improve monitoring of clinical deterioration. Optical coherence tomography (OCT) could be such a tool. However, sufficient longitudinal data of retinal neuroaxonal degeneration as a marker of disease progression exist only for PwMS with a relapsing-remitting course (RRMS) so far. In contrast, longitudinal data of retinal layers in patients with primary-progressive MS (PPMS) are inconsistent, and the association of OCT parameters with ambulatory performance in PwMS has rarely been investigated. We aimed to investigate the relative annual rates of change in retinal layers in PwMS (RRMS and PPMS) compared with healthy controls (HC) using OCT and to evaluate their association with ambulatoryfunctionalscore (AS) worsening in PPMS. A retrospective analysis of a longitudinal OCT dataset of the retinal layers of PwMS and HC from two MS centers in Germany was performed. Walking ability was measured over a standardized distance of 500 m, and changes during the observation period were categorized using the AS and the expanded disability status scale (EDSS). 61 HC with 121 eyes and 119 PwMS (PPMS: 57 patients with 108 eyes; RRMS: 62 patients with 114 eyes) were included. The median follow-up time for PwMS was 3 years. The relative annual change of pRNFL (peripapillary retinal nerve fiber layer) and INL (inner nuclear layer) was significantly different in PwMS compared with HC. RRMS and PPMS subgroups did not differ in the annual atrophy rates. In patients with PPMS, worsening of the AS was significantly associated with increased thinning of the TMV (total macular volume), GCIP (ganglion cell and inner plexiform layer), and ONPL (outer nuclear and outer plexiform layer) (all p-value < 0.05, r > 0.30). For every -0.1% decrease in the TMV, GCIP, and ONPL, the risk of a deterioration in the AS increased by 31% (hazard ratio (HR): 1.309), 11% (HR: 1.112), and 16% (HR: 1.161), respectively. In addition, worsening EDSS in PPMS was significantly associated with the relative annual atrophy rates of pRNFL, TMV, and GCIP (all p-value < 0.05). Disability progression in PPMS can be measured using OCT, and increasing annual atrophy rates of the inner retinal layers are associated with worsening ambulation. OCT is a robust and side-effect-free imaging tool, making it suitable for routine monitoring of PwMS.

Metabolic costs of walking and arm reaching in persons with mild multiple sclerosis

Movement slowness is a common and disruptive symptom of multiple sclerosis (MS). A potential cause is that individuals with MS slow down to conserve energy as a behavioral adjustment to heightened metabolic costs of movement. To investigate this prospect, we measured the metabolic costs of both walking and seated arm reaching at five speeds in persons with mild MS (pwMS; n = 13; 46.0 ± 7.7 yr) and sex- and age-matched controls (HCs; n = 13; 45.8 ± 7.8 yr). Notably, the cohort of pwMS was highly mobile and no individuals required a cane or aid when walking. We found that the net metabolic power of walking was approximately 20% higher for pwMS across all speeds (P = 0.0185). In contrast, we found no differences in the gross power of reaching between pwMS and HCs (P = 0.492). Collectively, our results suggest that abnormal slowness of movement in MS-particularly reaching-is not the consequence of heightened effort costs and that other sensorimotor mechanisms are playing a considerable role in slowing.NEW & NOTEWORTHY Individuals with multiple sclerosis (MS) often move more slowly than those without the disease. A possible cause is that movements in MS are more energetically expensive and slowing is an adaptation to conserve metabolic resources. Here, we find that while walking is more costly for persons with MS, arm-reaching movements are not. These results bring into question the driving force of movement slowness in MS and implicate other motor-related networks contributing to slowing.

A Thematic Survey on the Reporting Quality of Randomized Controlled Trials in Rehabilitation: The Case of Multiple Sclerosis

BACKGROUND AND PURPOSE

Optimal reporting is a critical element of scholarly communications. Several initiatives, such as the EQUATOR checklists, have raised authors' awareness about the importance of adequate research reports. On these premises, we aimed at appraising the reporting quality of published randomized controlled trials (RCTs) dealing with rehabilitation interventions. Given the breadth of such literature, we focused on rehabilitation for multiple sclerosis (MS), which was taken as a model of a challenging condition for all the rehabilitation professionals.A thematic methodological survey was performed to critically examine rehabilitative RCTs published in the last 2 decades in MS populations according to 3 main reporting themes: (1) basic methodological and statistical aspects; (2) reproducibility and responsiveness of measurements; and (3) clinical meaningfulness of the change.

SUMMARY OF KEY POINTS

Of the initial 526 RCTs retrieved, 370 satisfied the inclusion criteria and were included in the analysis. The survey revealed several sources of weakness affecting all the predefined themes: among these, 25.7% of the studies complemented the P values with the confidence interval of the change; 46.8% reported the effect size of the observed differences; 40.0% conducted power analyses to establish the sample size; 4.3% performed retest procedures to determine the outcomes' reproducibility and responsiveness; and 5.9% appraised the observed differences against thresholds for clinically meaningful change, for example, the minimal important change.

RECOMMENDATIONS FOR CLINICAL PRACTICE

The RCTs dealing with MS rehabilitation still suffer from incomplete reporting. Adherence to evidence-based checklists and attention to measurement issues and their impact on data interpretation can improve study design and reporting in order to truly advance the field of rehabilitation in people with MS.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1 available at: http://links.lww.com/JNPT/A424).

Dynamic balance during walking in people with multiple sclerosis: A cross-sectional study

Dynamic balance disorders are common impairments in People with Multiple Sclerosis (PwMS) leading to gait disorders and a higher risk of falling. However, the assessment of dynamic balance is still challenging and instrumented indexes provide objective and quantitative data of CoM movement and Base of Support, which are considered that are two key factors describing dynamic balance. This study aims at validating recent instrumented indexes based on the inverted pendulum model and characterizing dynamic balance disorders in PwMS. We clinically assessed 20 PwMS and we collected instrumented gait data through an optoelectronic system. Data from 20 Healthy Subjects (HS) were also considered as normative reference. Margin of Stability by HoF (MoS_Hof) and by Terry (MoS_Terry) at midstance, and Foot Placement Estimator (D_FPE) at heel strike were calculated in mediolateral (ML) and anteroposterior (AP) directions, for both less affected and most affected sides for PwMS and for dominant and non-dominant side for HS. MoS_HOF well discriminated between PwMS and HS, followed by MoS_TERRY in ML direction (Mos_HOF: PwMS = 130.0 ± 27.2 mm, HS = 106.5 ± 18.6 mm, p < 0.001, MoS_TERRY: PwMS = 75.1 ± 24.3 mm, HS = 56.5 ± 23.4 mm, p < 0.02). MoS_HOF and MoS_TERRY discriminated between sides in both directions in PwMS. D_FPE did not discriminate between groups and sides. Moderate correlations were found between all three indexes and clinical balance scales (from r = 0.02 to r = 0.66), energy recovery (from r = -0.77 to r = -0.11), single stance time (from r = -0.11 to r = 0.80) and step length (from r = -0.83 to r = -0.20). MoS_HOF resulted in the best index to describe dynamic balance disorders in PwMS: they keep CoM position far from the lateral and as close as possible to the anterior boundary of the Base of Support as preventive strategies to control balance perturbations. Furthermore, PwMS seem to use different preventive strategies in accordance with the specific lower limb impairments. This alters the physiological gait mechanisms increasing the energy expenditure and decreasing gait quality and dynamic balance.

Thalamic atrophy moderates associations among aerobic fitness, cognitive processing speed, and walking endurance in persons with multiple sclerosis

BACKGROUND AND OBJECTIVES

Thalamic atrophy (TA) represents a biomarker of neurodegeneration and associated dysfunction/decline in physical and cognitive functioning among persons with multiple sclerosis (MS). Aerobic fitness, as an end point of exercise training, represents a promising target for restoring function in MS, but it is unknown if such effects differ by TA. This cross-sectional study examined whether aerobic fitness was differentially associated with cognitive processing speed and walking endurance in persons with MS who present with and without TA.

METHODS

44 fully ambulatory persons with MS completed a graded exercise test for measuring aerobic fitness (VO_2peak) and underwent 3T MRI for measuring TA, the Symbol Digit Modalities Test (SDMT), and the 6-min walk (6MW). We performed Spearman correlations (r_s) among VO_2peak, SDMT, and 6MW scores overall, and in persons with and without TA. We applied Fisher's z-test for comparing correlations based on TA status.

RESULTS

When controlling for age, EDSS score, and global MRI measures of atrophy, VO_2peak was strongly associated with SDMT scores (pr_s = 0.74, p < 0.01) and 6MW performance (pr_s = 0.77, p < 0.01) in persons with TA, whereas VO_2peak was not associated with SDMT scores (pr_s =  - 0.01, p = 0.99) or 6MW performance (pr_s = 0.25, p = 0.38) in those without TA. The correlations between VO_2peak and SDMT (z = 2.86, p < 0.01) and VO_2peak and 6MW (z = 2.33, p = 0.02) were significantly stronger in the TA group.

DISCUSSION

This study provides initial evidence of strong, selective associations among aerobic fitness, cognitive processing speed, and walking endurance in persons with TA as a biomarker for MS-related neurodegeneration. Such data support TA as a moderator of the association among aerobic fitness, cognitive processing speed, and walking endurance in persons with MS. Future research should carefully consider the role of TA when designing trials of aerobic exercise, cognition, and mobility in MS.

Restless legs syndrome severity associated with reduced physical function in adults with multiple sclerosis

BACKGROUND

Restless legs syndrome (RLS) is a sleep disorder that occurs in approximately 26 % of adults with multiple sclerosis (MS) and may be associated with reduced physical function.

RESEARCH QUESTION

The present study examined the relationship between RLS symptomology (i.e., overall severity, frequency, and occurrence) and physical function outcomes in adults with MS who had RLS.

METHODS

Participants (N = 22) with MS who had RLS came into the laboratory for a single session wherein a rater performed a brief neurological examination for scoring the Expanded Disability Status Scale (EDSS) and completed a demographics questionnaire, the International Restless Legs Syndrome Study Group Scale (IRLS), and the Restless Legs Syndrome Scale-6 (RLS-6) followed by the Short Physical Performance Battery (SPPB) and the Six-minute Walk Test (6 MW).

RESULTS

Bivariate Spearman's rho correlation analyses indicated total IRLS had a strong, negative association with total distance traveled during the 6 MW (ρ = -0.50) and a moderate association with SPPB scores (ρ = -0.43), but not EDSS scores (ρ = 0.28). RLS severity during the day while active had strong, negative associations with total distance traveled during the 6 MW (ρ = -0.61) and SPPB scores (ρ = -0.52), but not EDSS scores (ρ = 0.13).

SIGNIFICANCE

We observed associations between worse overall RLS severity and RLS severity during the day while active with reduced performance during the 6 MW and lower SPPB scores. The management of RLS may offer an opportunity for mitigating reductions in physical function in adults with MS who have RLS.

The pathophysiology of motor fatigue and fatigability in multiple sclerosis

Multiple Sclerosis (MS) is a heterogeneous immune mediated disease of the central nervous system (CNS). Fatigue is one of the most common and disabling symptom of MS. It interferes with daily activities on the level of cognition and motor endurance. Motor fatigue can either result from lesions in cortical networks or motor pathways (“primary fatigue”) or it may be a consequence of detraining with subsequent adaptions of muscle and autonomic function. Programmed exercise interventions are used frequently to increase physical fitness in MS-patients. Studies investigating the effects of training on aerobic capacity, objective endurance and perceived fatigability have yielded heterogenous results, most likely due to the heterogeneity of interventions and patients, but probably also due to the non-uniform pathophysiology of fatigability among MS-patients. The aim of this review is to summarize the current knowledge on the pathophysiology of motor fatigability with special reference to the basic exercise physiology that underlies our understanding of both pathogenesis and treatment interventions.

Relationships between balance and physical fitness variables in firefighter recruits

BACKGROUND

Research has suggested that balance ability contributes to musculoskeletal injury (MSKI) rates in firefighters. Though the Y-Balance Test (YBT) can predict injury, it is unclear what physical measures inform YBT performance in firefighters. Thus, there is a lack of knowledge regarding best practice for improving balance in firefighters.

OBJECTIVE

To evaluate the relationship between the YBT and fitness measures, including body composition, aerobic capacity, functional total-body power, upper and lower-body strength, and movement efficiency, among firefighters.

METHODS

Dynamic balance (YBT), body mass index (BMI), body-fat percentage (BF%), fat free mass (FFM), aerobic capacity (VO2max), stair climb (SC), upper (1RMbench) and lower-body (1RMsquat) strength, and Fusionetics™ Movement Efficiency Screen (ME) measures were collected among 35 firefighter recruits. Pearson correlation coefficients were used to examine relationships between YBT and the performance measures.

RESULTS

Dynamic balance ability in firefighter recruits is significantly (p < 0.05) related to BMI, lower-body strength, and movement quality, but not with aerobic capacity, stair climb performance, and upper body strength.

CONCLUSIONS

Greater YBT performance in firefighter recruits is associated with lower BMI, greater functional movement, and greater lower-body strength. Future research is warranted to incorporate these elements into balance training programs for firefighter recruits.

Cognitive Function and Whole-Brain MRI Metrics Are Not Associated with Mobility in Older Adults with Multiple Sclerosis

Due to advances in disease-modifying medications and earlier management of comorbidities, adults with multiple sclerosis (MS) are living longer, and this coincides with the aging of the general population. One major problem among older adults with and without MS is limited mobility, a consequence of aging that often negatively affects quality of life. Identifying factors that contribute to mobility disability is needed to develop targeted rehabilitation approaches. This study examined cognitive processing speed and global brain atrophy as factors that may contribute to mobility disability in older adults with and without MS. Older adults (≥55 years) with MS (n = 31) and age- and sex-matched controls (n = 22) completed measures of mobility (Short Physical Performance Battery) and cognitive processing speed (Symbol Digit Modalities Test) and underwent an MRI to obtain whole-brain metrics (gray matter volume, white matter volume, ventricular volume) as markers of atrophy. Mobility was significantly worse in the MS group than in the control group (p = 0.004). Spearman correlations indicated that neither cognitive processing speed (MS: r_s = 0.26; Control: r_s = 0.08) nor markers of global brain atrophy (MS: r_s range = −0.30 to −0.06; Control: r_s range = −0.40 to 0.16) were significantly associated with mobility in either group. Other factors such as subcortical gray matter structures, functional connectivity, exercise/physical activity, and cardiovascular fitness should be examined as factors that may influence mobility in aging adults with and without MS.

Body fat-related differences in gait parameters and physical fitness level in weight-matched male adults

BACKGROUND

Increased body weight is associated with an increased magnitude of foot pressures. Although body mass index (BMI) has been widely used in the assessment of obesity, BMI does not differentiate between muscle and adipose tissue, which may play an important role in characterizing walking patterns. The purpose of the study was to compare gait biomechanics between obese and weight-matched control group.

METHODS

Sixty male adults were assigned to a normal and obese group based on body fat percentage. Body compositions and BMI were measured by the bioelectrical impedance method. Plantar pressure and gait parameters were recorded with a force-distribution-measure treadmill system during walking at the preferred speed. Physical fitness assessment was also conducted to assess muscular strength, muscular endurance, maximum oxygen uptake, flexibility, and agility.

FINDINGS

Normal group displayed greater muscle strength, flexibility, and maximum oxygen uptake compared to the obese group. Foot-pressure measures indicated significantly greater peak pressure values for the front and rear of the foot in the normal group. Greater muscle strength was correlated with higher BMI and lower body fat percentage. A significant negative correlation between body fat percent and gait variables was also exhibited.

INTERPRETATION

The results demonstrated different force application patterns during walking between the obese and weight-matched control group, indicating a potential influence of body fat percent on foot pressure characteristics in walking. Therefore, a comprehensive classification of obesity, including body fat percent, should be administered for the prescription of safe physical activity.

Fall-related functional impairments in patients with neurological gait disorder

Falls are common in patients with neurological disorders and are a primary cause of injuries. Nonetheless, fall-associated gait characteristics are poorly understood in these patients. Objective, quantitative gait analysis is an important tool to identify the principal fall-related motor characteristics and to advance fall prevention in patients with neurological disorders. Fall incidence was assessed in 60 subjects with different neurological disorders. Patients underwent a comprehensive set of functional assessments including instrumented gait analysis, computerized postural assessments and clinical walking tests. Determinants of falls were assessed by binary logistic regression analysis and receiver operator characteristics (ROC). The best single determinant of fallers was a step length reduction at slow walking speed reaching an accuracy of 67.2% (ROC AUC: 0.669; p = 0.027). The combination of 4 spatio-temporal gait parameters including step length and parameters of variability and asymmetry were able to classify fallers and non-fallers with an accuracy of 81.0% (ROC AUC: 0.882; p < 0.001). These findings suggest significant differences in specific spatio-temporal gait parameters between fallers and non-fallers among neurological patients. Fall-related impairments were mainly identified for spatio-temporal gait characteristics, suggesting that instrumented, objective gait analysis is an important tool to estimate patients' fall risk. Our results highlight pivotal fall-related walking deficits that might be targeted by future rehabilitative interventions that aim at attenuating falls.

The Effect of Exercise Training on Gait, Balance, and Physical Fitness Asymmetries in Persons With Chronic Neurological Conditions: A Systematic Review of Randomized Controlled Trials

Background: Persons with chronic neurological conditions (CNCs) often present with asymmetrical impairments, creating significant differences between contralateral limbs in body functions. These asymmetries have been associated with reduced mobility and balance, and are often targeted for reduction during rehabilitation. Exercise training has established benefits for persons with CNCs, and may have positive effects on asymmetry outcomes.

Objectives: The purpose of this review was to summarize the current evidence for the effects exercise training on gait, balance, and physical fitness asymmetry in randomized control trials (RCTs) of persons with CNCs.

Methods: A search of four electronic databases (EMBASE, CINAHL, SPORTdiscus, and ovidMEDLINE) was conducted following the structured Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Results: The search retrieved 3,493 articles, with 465 articles assessed for eligibly, and nine articles meeting the criteria for inclusion. Of the included articles, five incorporated resistance exercise, three incorporated aerobic exercise, and one incorporated combined exercise (i.e., resistance and aerobic exercise). Gait asymmetry improved significantly in four studies after resistance, aerobic, and combined exercise. Significant improvements in weight bearing asymmetry were reported in three studies after resistance exercise. One study reported significant improvements in both gait and balance asymmetry after resistance exercise.

Conclusions: Preliminary evidence suggests that exercise training, as a component of rehabilitation, may have positive effects on gait and balance asymmetry in persons with CNCs. Several limitations of the current literature were noted, including a limited number of studies, combination of exercise with other rehabilitation modalities, a lack of reporting on exercise prescriptions (e.g., number of repetitions, intensity), and variability in the calculation of asymmetry outcomes. These limitations prevent definitive conclusions on the effects of exercise training on asymmetry outcomes. Future trials are needed to determine the potential of exercise training for reducing asymmetry in persons with CNCs.

Reference Values for Isometric, Dynamic, and Asymmetry Leg Extension Strength in Patients with Multiple Sclerosis

Having recognized the value of resistance training in patients with multiple sclerosis (PwMS), there are a lack of lower limb normative reference values for one repetition maximum (1RM) and maximal voluntary isometric contraction (MVIC) in this population. Hence, the purposes of this study were to provide reference values for 1RM and MVIC of knee extensors in PwMS across the disability spectrum and to examine knee extension strength asymmetry. Three hundred and ninety PwMS participated in the study, performing MVIC and 1RM tests of bilateral (both legs together at once) and unilateral (each leg singly) knee extensors. There was no difference in 1RM according to the disease course of MS, but there was according to the degree of neurological disability, being more preserved in those with a lower degree of disability. MVIC tends to be higher in patients with relapsing-remitting MS respect those with progressive MS, and in patients with lower levels of neurological disability. Asymmetry above the values considered normal in 1RM was present in 20-60% of patients and 56-79% in the MVIC test, depending on the type of MS and tended to be lower in those with less disability. Reference values are given by quartiles for 1RM, MVIC, and asymmetry.

Research on lower extremity health in patients with multiple sclerosis: a systematic scoping review

Background

Multiple sclerosis (MS) often affects ambulation and the function of the lower limbs. However, little is known about how much research has been conducted on lower extremity health in patients with MS.

Objective

To analyse empirical studies and their evidence on lower extremity health in patients with MS, in order to identify the need for future studies in key areas.

Methods

A systematic scoping review was conducted. A literature search of Medline (PubMed), CINAHL (EBSCO) and the Cochrane Library databases was performed. The search covered the period up to 15 January 2020 from the earliest records available. This led to the inclusion of 42 empirical articles. The data were analysed using content analysis and quantification techniques.

Results

The research on lower extremity health focused primarily on two main areas: gait and lower extremity muscle strength. Lower extremity health was assessed using a variety of methods, most of which consisted of objective physical tests and gait analysis. Patients with MS had many problems with the health of their lower extremities, which manifested in walking difficulties, balance problems, muscle weaknesses and spasticity. In the feet, pes cavus, claw toes, oedema and altered foot sensation were common.

Conclusions

MS affects lower limb and foot health, and these problems can affect patients’ daily lives. However, the extent of these problems is poorly understood, partly due to the dearth of research on lower limb and foot health. Therefore, further research is warranted in order to better understand the impact of MS on foot and lower limb health in everyday life.

Social cognitive theory as a guide for exercise engagement in persons with multiple sclerosis who use wheelchairs for mobility

Multiple sclerosis (MS) is an immune-mediated neurodegenerative disease of the brain, optic nerves and spinal cord. Among persons with MS, 30% experience significant mobility impairment that requires use of a wheelchair for mobility. Exercise is an evidence-based second-line therapy that can improve mobility; however, little research has focused on individuals that use wheelchairs for mobility. Framed by social cognitive theory (SCT), we conducted a formative qualitative study examining exercise status and perceptions among 20 persons with MS who use wheelchairs for mobility. Using deductive, semantic thematic analysis, we coded for SCT variables (i.e. self-efficacy, knowledge, outcome expectations, barriers and facilitators) and identified participants as regular or inconsistent exercisers. In total, 12 participants were classified as regular exercisers and 8 inconsistent exercisers. Regular exercisers more frequently reported high self-efficacy, consistent exercise knowledge and numerous facilitators. All participants reported some positive outcome expectations and several barriers and facilitators. These findings can inform future intervention studies supporting exercise behavior change through SCT. Strategies such as increasing self-efficacy, imparting instructional materials, shaping realistic outcome expectations and providing tools directed toward overcoming barriers and identifying facilitators may work to support the exercise endeavor of persons with MS who use wheelchairs for mobility.

Persons with Multiple Sclerosis Exhibit Strength Asymmetries in both Upper and Lower Extremities

OBJECTIVE

To characterize strength asymmetries in the upper and lower extremities in persons with multiple sclerosis (PwMS) with severe disability, and examine associations between asymmetries and functional, symptomatic, and participatory outcomes.

DESIGN

Cross-sectional.

SETTING

University research laboratory.

PARTICIPANTS

25 PwMS with Expanded Disability Status Scale scores between 6.0-8.0.

MAIN OUTCOME MEASURES

Bilateral strength and asymmetry scores for muscle groups at the ankle, knee, and shoulder joints in addition to grip strength.

RESULTS

Significant differences were observed between all contralateral strength measures, with asymmetry scores ranging between 20-32%. A high prevalence of asymmetry (i.e., score>10%) was observed for all strength measures, with 92% of participants having four or more affected measures. Significant associations were observed between dorsiflexion asymmetry and physical health-related quality of life (ρ= -0.69; p<0.001), and between shoulder flexion asymmetry and lower extremity function (ρ= -0.62; p=0.001). Plantarflexion (ρ= 0.61; p=0.003) and knee flexion (ρ= 0.63; p=0.002) asymmetry were significantly associated with lower extremity functional asymmetry.

CONCLUSIONS

A high prevalence of asymmetry in the upper and lower extremities was observed, with asymmetry scores exceeding those previously reported in PwMS with mild-to-moderate disability. Rehabilitation strategies should consider a full body approach to address strength asymmetries.

Associations of lower limb joint asymmetry with fatigue and disability in people with multiple sclerosis

BACKGROUND

An early symptom of multiple sclerosis is unilateral weakness, particularly in the lower limbs, which is associated with strength asymmetries. The purpose of this exploratory study was to examine strength asymmetries at the hip, knee, and ankle joints, and to investigate the associations between lower limb strength asymmetries and self-reported fatigue severity and disability in people with multiple sclerosis.

METHODS

Sixteen mildly-disabled people with multiple sclerosis (females = 9) completed isokinetic maximal voluntary contractions of the hip extensors and flexors, knee extensors and flexors, and ankle plantar flexors and dorsiflexors. Asymmetry indices between the strength of the more- and less-affected lower limbs at each muscle group and the percent agreement between self-reported and objectively-determined more-affected lower limb were calculated. Patient Determined Diseases Steps and Fatigue Severity Scale were also completed.

FINDINGS

All joints showed asymmetry (asymmetry indices ≥10%). Knee flexors (mean [SD]; 49.9 [37.8%]) and ankle plantar flexors (46.6 [35.5%]) had the largest asymmetry indices. Hip and knee extensors had the lowest asymmetry indices (21.1 [18.1%] and 30.1 [24.7%], respectively) and the highest agreement between self-reported and objectively-determined more-affected lower limb (93.3 and 93.8, respectively). The hip extensor asymmetry index was correlated with the Fatigue Severity Scale (r = 0.542, p = 0.037).

INTERPRETATION

For the assessment of strength asymmetries in people with multiple sclerosis, it is suggested to 1) include measures of hip, knee, and ankle strength asymmetries, 2) include subjective perceptions and objective measures of strength asymmetries concurrently, and 3) to include measures of sensory function (proprioception).

Physical activity and peak oxygen consumption are associated with walking in multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system with a prevalence of nearly 1 million adults in the United States. MS results in declines in physical activity and peak oxygen consumption that might be independently associated with declines in walking performance. Therefore our purpose was to evaluate the association between physical activity and peak oxygen consumption with walking performance in individuals with MS.

METHODS

Fifty individuals with MS between the ages of 18-70 yrs. (Female: 38; 46  ±  12 yrs.; BMI: 28.5  ±  6.4; EDSS: 3.3 [IQR: 2.5-4]) performed a maximal incremental cycle test to assess peak oxygen consumption (VO_2peak), and wore an accelerometer for one week to measure moderate-to-vigorous physical activity (MVPA). Subjects further completed a timed 25-foot walk test (T25FW) and 6-minute walk (6MW) to measure walking performance.

RESULTS

MVPA and VO₂peak were correlated with 6MW and T25FW (p < 0.05). When combined in multivariate regression analyses, VO_2peak and MVPA were both significant contributors of T25FW speed and 6MW, but after controlling for sex and age, MVPA was the only significant contributor (β = 0.32 and β = 0.44, respectively).

CONCLUSION

Both higher MVPA and VO_2peak were associated with better walking performance and in a combined model physical activity, but not peak oxygen consumption, remained an independent contributor to walking performance in individuals with MS. These results suggest that improving MVPA is a potential target for interventions to improve walking performance in persons with MS.

The importance of lower-extremity muscle strength for lower-limb functional capacity in multiple sclerosis: Systematic review

BACKGROUND

Lower-limb functional capacity is impaired in most people with multiple sclerosis (PwMS). Reductions in lower-extremity muscle mechanical function (e.g., muscle strength) appear to have critical implications for lower-limb functional capacity. However, no review has summarized the current knowledge about the importance of muscle strength for functional tasks in PwMS. Expanding the current knowledge would advance the design of both clinical and research interventions aiming to improve functional capacity in PwMS.

OBJECTIVES

(1) To identify studies that measured lower-extremity muscle mechanical function and lower-limb functional capacity outcomes in PwMS, and (2) to map associations between muscle strength and functional capacity.

METHODS

This review was based on a literature search (databases: PubMed, Embase). Included studies had to report data on lower-extremity muscle mechanical function and lower-limb functional capacity outcomes in PwMS. The associations between muscle strength and functional capacity were analyzed by using the reported correlation coefficients (R) recalculated to the determination coefficient R². Randomized trials and observational studies were included.

RESULTS

A total of 59 articles were reviewed; 17 (773 participants) reported associations between muscle strength and functional capacity. Lower-extremity muscle mechanical function explained a significant part of the variance in most lower-limb functional capacity tests (approximately 20-30%). This was particularly evident in muscle strength from the weakest leg. Muscle strength was predominantly tested on knee extensors and knee flexors by using isokinetic dynamometry during maximal isometric (0°/s) and dynamic (30-60°/s) contractions. Walking tests such as the timed 25-Foot Walk Test and 10-Min, 2-Min and 6-Min Walk Test were the most frequently performed functional capacity tests.

CONCLUSIONS

In PwMS, muscle strength of particularly the weakest limb explains 20% to 30% of the variance across a number of lower-limb functional capacity tests. Thus, exercise programs should focus on increasing lower-extremity muscle mechanical function in PwMS and minimizing strength asymmetry between limbs.

Sensory nerve stimulation causes an immediate improvement in motor function of persons with multiple sclerosis: A pilot study

BACKGROUND

Multiple sclerosis (MS) symptoms reported in the first year of the disease include sensory impairment, fatigue, reduced mobility, and declines in hand function. The progressive reduction in motor function experienced by persons living with MS is invariably preceded by changes in sensory processing, which are strongly associated with the declines in both walking performance and manual dexterity.

AIMS

To assess the influence of concurrent sensory stimulation using augmented transcutaneous electrical nerve stimulation (aTENS) applied to leg and hand muscles on clinical tests of motor function in individuals whose mobility was compromised by MS.

METHODS

Thirteen persons with MS (52 ± 8 years; 6 women) and 12 age- and sex-matched healthy adults (52 ± 9 years) met the inclusion criteria. Participants visited the lab on two occasions with one week between visits. Each visit involved the participant performing four tests of motor function and completing two health-related questionnaires (PDDS and MSWS-12). The tests assessed walking performance (6-min test and 25-ft test), dynamic balance (chair-rise tes, and manual dexterity (grooved pegboard test). aTENS was applied through pads attached to the limbs over the tibialis anterior and rectus femoris muscles of the affected leg, and over the median nerve and the thenar eminence of the dominant hand. The pads were attached during both visits, but the current was only applied during the second visit. The stimulation comprised continuous asymmetrical biphasic pulses (0.2 ms) at a rate of 50 Hz and an intensity that elicited slight muscle contractions.

RESULTS

At baseline and during both treatment sessions, the performance on all four tests of motor function was worse for the MS group than the Control group. The MS group experienced significant improvements in all outcomes during the aTENS session with medium-to-large effect sizes. PDDS ratings improved (from 2.8 ± 1.3 to 2.0 ± 1.5; effect size d = -0.70) and the MSWS-12 scores declined (from 36 ± 11 to 28 ± 12; effect size d = -1.52). The concurrent application of aTENS enabled the MS group to walk further during the 6-min test (from 397 ± 174 m to 415 ± 172 m; effect size d = 0.81), to complete the 25-ft test in less time (6.7 ± 3.0 s to 6.3 ± 2.9 s; effect size d = -0.76), to increase the counts in the chair-rise test (from 11.2 ± 3.8 to 13.6 ± 4.8; effect size d = 1.52), and to perform the grooved pegboard test more quickly (from 110 ± 43 s to 99 ± 37 s; effect size d = -0.98). The only significant effect for the Control group was a significant increase in the 6-min walk distance (from 725 ± 79 to 740 ± 82 m; effect size d = 0.87).

CONCLUSIONS

Stimulation of sensory fibers with aTENS evoked clinically significant improvements in four tests of motor function and the self-reported level of walking limitations in persons who were moderately disabled by MS. Moreover, the improvements in function elicited by the concurrent application of aTENS were immediate.

Evaluating functional electrical stimulation (FES) cycling on cardiovascular, musculoskeletal and functional outcomes in adults with multiple sclerosis and mobility impairment: A systematic review

BACKGROUND

People with Multiple Sclerosis (PwMS) are at an increased risk of diseases associated with low levels of physical activity (PA). Deconditioning may lead to an acceleration in the development of secondary complications from MS, impairing physical function and exacerbating disease progression. Functional Electrical Stimulation (FES) Cycling may provide a suitable lower limb exercise intervention for PwMS with mobility impairment. The effects of FES cycling on cardiovascular, musculoskeletal and functional outcomes for PwMS with mobility impairment are yet to be investigated to date.

OBJECTIVE

The objective of this review was to systematically examine the outcomes of PwMS with mobility impairment following FES cycling intervention.

METHODS

A systematic search of four electronic databases (MEDLINE, Web of Science, CINAHL and PEDro) from their inception to 8th January 2019 was performed. Inclusion criteria was (1) include human participants with definite diagnosis of MS (2) participants had to be aged 18 years or older (3) include participants with mobility impairment (determined as an average participant EDSS ≥ 6.0) (4) evaluate FES cycling as an intervention study.

RESULTS

Initial searches found 1163 studies. 9 of which met the full inclusion criteria: 5 pre-post studies with no control group, 2 randomised controlled trials (RCTs), 1 retrospective study and 1 case study. Two studies had the same participant group and intervention but reported different outcomes. Outcome data was available for n = =76 unique participants, with n = =82 completing a FES cycling intervention. Of the n = =4 papers with clear dropout rates, pooled dropout rate was 25.81%. Two papers reported non-significant improvements in aerobic capacity following a FES cycling intervention. Four papers reported no change in lower limb strength and two papers reported significant reductions in spasticity post training. Four studies failed to provide information regarding adverse events with the other studies reporting n = =10 adverse events across 36 participants.

CONCLUSION

Findings suggest FES cycle training may reduce CVD risk alongside trends for a reduction in spasticity post training, however the low quality of the literature precludes any definitive conclusions. FES cycle training appears to be well tolerated in PwMS with mobility impairment, with no serious adverse events.

Quantitative Synthesis of Timed 25-Foot Walk Performance in Multiple Sclerosis

OBJECTIVE

To provide a meta-analysis of articles that have included the timed 25-foot walk (T25FW) in persons with multiple sclerosis (MS), quantify differences in T25FW scores between those with MS and controls without MS, and quantify differences between categories of disability status and clinical disease courses within MS.

DATA SOURCES

The literature search was conducted using 4 databases (Google Scholar, PubMed, Cumulative Index to Nursing and Allied Health, EBSCO Host). We searched reference lists of published articles to identify additional articles.

STUDY SELECTION

A systematic literature search identified articles reporting average T25FW performance in seconds between those with MS and controls without MS, between those with MS who had mild and moderate and/or severe disability status, and between relapsing-remitting and progressive clinical courses of MS.

DATA EXTRACTION

Information was extracted and categorized based on reported data: comparisons of controls without MS and MS, comparisons of mild and moderate and/or severe MS based on study-defined Expanded Disability Status Scale groups, and comparisons of relapsing-remitting and progressive MS clinical courses.

DATA SYNTHESIS

We performed a random effects meta-analysis to quantify differences between groups as estimated by effect sizes (ESs). We expressed the differences in Cohen d as well as the original units of the T25FW (ie, seconds).

CONCLUSIONS

There was a large difference in T25FW performance in MS compared with controls without MS (ES=-0.93, mean difference=2.4s, P<.01). Persons with moderate and/or severe disability walked substantially slower compared with mild disability (ES=-1.02, mean difference=5.4s, P<.01), and persons with progressive courses of MS walked substantially slower than relapsing-remitting MS (ES=-1.4, mean difference=13.4s, P<.01).

Evaluation of Power Production Asymmetry during Cycling in Persons with Multiple Sclerosis

Lower limb asymmetries have been observed in persons with multiple sclerosis (PwMS), and have been associated with mobility impairment. An incremental cycling test was performed on a cycle ergometer to determine peak power output (PPO) and peak oxygen consumption (VO₂peak). Then, participants cycled at 50%, 60%, and 70% of their PPO to assess the contribution of each lower limb to power production. Two-way repeated measures ANOVA was used to detect group × intensity differences in power production asymmetry. Eight PwMS and six healthy individuals (Non-MS) completed the study. No statistically significant (p > 0.05) group × intensity interactions or main effects were present when examining between-limb differences in power production. The current data do not indicate a statistically significant difference in power production asymmetry between groups and exercise intensities. Previous research has established a 10% difference between contralateral limbs as a threshold for asymmetry. The average asymmetry in power production in PwMS exceeded the 10% threshold at all measured outputs, suggesting the presence of asymmetry in power production.

Walking endurance in multiple sclerosis: Meta-analysis of six-minute walk test performance

BACKGROUND

The 6-minute walk (6 MW) is the most commonly applied measure of endurance walking capacity in persons with multiple sclerosis (MS); however, we are not aware of a quantitative synthesis of 6 MW performance in MS.

RESEARCH QUESTION

We undertook a meta-analysis quantifying the overall magnitude of difference in 6 MW performance between MS and healthy controls (HCs), and then within MS as a function of disability status. We further examined possible moderator variables of 6 MW performance.

METHODS

The systematic search was conducted for articles that included the 6 MW in persons with MS and involved comparison groups (i.e., HCs or MS disability subgroups (i.e., mild vs moderate-to-severe disability status)). The mean and standard deviation of the distance traveled during the 6 MW as well as sample sizes were entered into Comprehensive Meta-Analysis software and we estimated the overall effect size (Cohen's d) using a random effects model and examined categorical variables as possible moderators (e.g., instruction protocol, provision of encouragement, method of distance measurement, and course description).

RESULTS

Thirty-four studies met inclusion criteria with a total sample size of 3204 persons (MS: 2683; HC: 521) yielding 42 total comparisons. Persons with MS walked a shorter distance than HCs (mean difference = -177.2 ± 19.1 m) with a large effect size (d = - 1.87). Persons with mild disability walked further than those with moderate-to-severe disability (mean difference = 185.19 ± 9.2 m) with a large effect (d = 1.83). The categorical variables of provision of encouragement and course layout moderated the effect of MS and course layout moderated the effect of disability status on 6 MW performance.

SIGNIFICANCE

This meta-analysis of 6 MW performance defines mean difference in 6 MW performance in MS compared with HCs and provides an estimate of the disease-related effect of MS on endurance walking capacity for application within clinical research and practice.

Physical activity is associated with neuromuscular and physical function in patients with multiple sclerosis independent of disease severity

PURPOSE

Examine the association between physical activity and neuromuscular and physical function in patients with multiple sclerosis when also considering disease severity.

METHODS

91 patients with multiple sclerosis were enrolled. Assessments included physical activity by 7-day thigh-worn accelerometry, knee extensor neuromuscular function by dynamometry (maximal isometric muscle strength, rate of force development (0-50 ms)), and physical function by 5× sit-to-stand, 2-min walk test, and timed 25 ft walk test. Physical activity tertile comparisons along with simple and multiple regressions (adjusting for age, gender, EDSS, time since diagnosis) were performed.

RESULTS

Physical activity tertiles revealed differences (p < 0.05) in maximal muscle strength (1.77 ≈ 1.97 < 2.28 Nm/kg), rate of force development (4.66 < 8.03 ≈ 10.55 Nm/kg/s), 5× sit-to-stand (11.4 ≈ 9.7 > 8.5 s), 2-min walk test (153 < 183 < 207 m), and timed 25 ft walk test (6.3 > 4.4 > 4.3 s). Moreover, physical activity was associated (p < 0.05) with maximal muscle strength and rate of force development (r²  =  0.13-0.15) along with 5× sit-to-stand, 2-min walk test, and timed 25 ft walk test (r² = 0.18-0.24), also after adjusting for age + gender + EDSS + time since diagnosis (r² = 0.25-0.37 and 0.24-0.52), with physical activity consistently being a strong predictor.

CONCLUSIONS

Higher levels of physical activity are associated with greater neuromuscular and physical function in ambulatory patients with multiple sclerosis independent of disease severity. These findings emphasize the importance of performing regular physical activity at all stages of multiple sclerosis.IMPLICATIONS FOR REHABILITATIONPhysical activity is associated with neuromuscular and physical function, independent of disease severity.Physical activity may be important in improving or preserving neuromuscular and physical function at all stages of ambulatory multiple sclerosis patients, yet longitudinal studies are warranted.Clinicians and rehabilitation professionals should encourage ambulatory patients at all stages of their disease to be as physically active as possible.

Physical activity patterns and multimorbidity burden of older adults with different levels of functional status: NHANES 2003-2006

BACKGROUND

Physical function and physical activity decrease with age, but differences in physical activity patterns within different physical functioning groups are unknown.

OBJECTIVES

To describe physical activity patterns and multimorbidity burden by physical function group and age.

METHODS

Actigraph accelerometer-derived physical activity patterns were compared by physical function (high functioning, activity limitations, activity of daily living disabled) determined by questionnaire and age among 2174 older adults (mean age = 70.9, sd = 0.2 years) from the cross-sectional 2003-2006 National Health and Nutrition Examination Survey. Associations between physical function, physical activity, and multimorbidity were examined.

RESULTS

Reduced physical function and increased age were associated with lower physical activity, increased sedentary time and a compressed activity profile. During the most active hour of the day (11:00 a.m.), the oldest, lowest physical functioning group was 82% less active than the youngest, highest physical functioning group. High functioning had over 30% more total activity counts, over 56% more time in moderate-to-vigorous activity, about 8% less time sedentary and took approximately one more sedentary break/hour than lower physical functioning groups. Gender differences in physical activity variables were prevalent for high functioning, but limited within reduced physical functioning groups. Physical function, age, total activity counts/day, and breaks in sedentary time/day were independently associated with multimorbidity (p < 0.005).

CONCLUSIONS

Reduced physical function and increased age are associated with physical activity levels, and all three are associated with multimorbidity. Understanding physical activity differences by physical function is important for designing interventions for older individuals at increased risk for mobility disability.

Energetic cost of walking and spasticity in persons with multiple sclerosis with moderate disability

BACKGROUND

The energetic cost of walking (Cw) is elevated in persons with multiple sclerosis (MS). This may be explained by spasticity and spatiotemporal parameters of gait.

OBJECTIVE

To examine the associations among Cw, spasticity of ankle plantarflexors, and spatiotemporal gait parameters in persons with MS who had moderate disability.

METHODS

The sample included 44 persons with MS who had moderate disability. Cw was measured over-ground during the 6-Minute Walk using indirect calorimetry and was calculated based on net oxygen consumption and walking speed (i.e., expressed ml·kg-1·m-1). Participants underwent the Modified Ashworth Scale as a measurement of spasticity and performed 4 trials of walking on a GAITRite electronic walkway for measurement of spatiotemporal gait parameters.

RESULTS

Spasticity was positively correlated with Cw (r = 0.52, p < 0.05) and inversely correlated with cadence (r = -.45, p < 0.05) and step length (r = -0.40, p < 0.05). Cadence (r = -0.59, p < 0.05) and step length (r = -0.56, p < 0.05) were inversely correlated with Cw. The regression analysis indicated that spasticity explained significant variance in Cw, and cadence and step length accounted for the association.

CONCLUSIONS

These results suggest that worse spasticity of the ankle plantarflexors and slower cadence and shorter step length, in turn, are responsible for elevated Cw among persons with MS with moderate disability. This supports the development of therapeutic, rehabilitation interventions delivered by clinicians for managing spasticity and the resulting Cw that may interfere with activities of daily living.

A cross-sectional study on the relationship between cardiorespiratory fitness, disease severity and walking speed in persons with Multiple Sclerosis

BACKGROUND

In persons with Multiple Sclerosis (PwMS) cardiorespiratory fitness has been associated with disease severity, walking capacity and comorbidities. However, current evidence is of moderate quality and a large-scale single-center study is needed to further elucidate these relationships OBJECTIVE: The purpose of the study was 1) to examine the relationship between cardiorespiratory fitness and disease severity in PwMS; 2) to investigate the relationship between cardiorespiratory fitness and walking speed and comorbidities; and 3) to examine the potential impact of Multiple Sclerosis (MS) disease type on these relationships METHODS: Data was collected from a database consisting of data from 700 inpatients at Valens Rehabilitation Center, Switzerland. VO₂peak (cardiorespiratory fitness), information on disease course and MS type, walking performance, comorbidities and anthropometric was eligible from 242 PwMS.

RESULTS

Cardiorespiratory fitness and Expanded Disability Status Scale (EDSS) was inversely related (r = -0.465, p < .01). A multiple linear regression analysis showed that an increase of 1 point on the EDSS score was associated with a decrease of 1.88 mL kg^-1 min^-1 and explained 36% of the variance, when adjusted for time since diagnosis, gender, age, and MS type. Walking speed and cardiorespiratory fitness was significantly correlated (r = 0.584, p < .01) and the relapse remitting MS (RRMS) group (1.12 ± 0.42 m/s) walked significantly faster than the secondary progressive MS (SPMS) group (0.91 ± 0.37 m/s) p < .05, but the difference was non-significant when adjusted for age, p = .429.

CONCLUSION

The present study shows that 1) an increase of 1 EDSS point is associated with a decrease of 1.88 mL kg^-1 min^-1 when adjusted for time since diagnosis, gender, age and MS type, 2) cardiorespiratory fitness and walking speed was significantly related but only minimally affected by MS type, and 3) hypertension is associated with a lower cardiorespiratory fitness level.

The relationship between corticospinal tract integrity and lower-extremity strength is attenuated when controlling for age and sex in multiple sclerosis

Muscle weakness, particularly in the lower-extremities, is common in multiple sclerosis (MS) and seemingly results from damage along white matter pathways in the central nervous system including the corticospinal tract (CST). This study examined CST structural integrity indicated by diffusion tensor imaging (DTI) related metrics (fractional anisotropy [FA], mean diffusivity [MD], radial diffusivity [RD], and axial diffusivity [AD]) as correlates of knee flexor (KF) and knee extensor (KE) muscle strength in MS. We included 36 persons with MS who underwent MRI and measurements of peak KE and KF strength using an isokinetic dynamometer. We examined associations using bivariate Spearman (rs) and partial Spearman correlation (prs) analyses controlling for age and sex. Peak KF strength was significantly associated with FA (rs = 0.42) and RD (rs = -0.36) and peak KE strength was significantly associated with MD (rs = -0.47) and RD (rs = -0.36). The correlations were attenuated after controlling for age and sex, but the relationship between KF strength and FA demonstrated a trend towards significance (prs = 0.33, p = 0.056). We provide evidence that the anatomical integrity of the CST may be associated with lower-extremity strength in MS. The attenuated correlations when controlling for age and sex suggest these factors, rather than MS per se, may be important contributors toward an association between CST DTI-metrics and KF and KE strength. Future rehabilitation trials of resistance training should consider including CST integrity as an outcome and/or predictor of strength adaptations.

Contributions of Ankle, Knee, Hip, and Trunk Muscle Function to Gait Performance in People With Multiple Sclerosis: A Cross-Sectional Analysis

BACKGROUND

The relative importance of lower extremity and trunk muscle function to gait in people with multiple sclerosis (MS) is unknown.

OBJECTIVE

This study aimed to investigate the association of lower extremity and trunk muscle function with gait performance in people who have MS and mild-to-moderate disability.

DESIGN

This was a cross-sectional, observational study.

METHODS

Participants were people who had an Expanded Disability Status Scale score of ≤ 5.5. Eleven lower extremity and trunk muscles were assessed using handheld dynamometry or endurance tests. Gait performance was assessed with the Timed 25-Foot (7.62 m) Walk (T25FW) and 6-Minute Walk Test (6MWT). Regression analysis was used to quantify the association between gait outcomes and muscle variables.

RESULTS

Seventy-two participants with MS and a mean Expanded Disability Status Scale score of 3.5 (SD = 1.14) were enrolled. Adjusted for age and sex, the multivariate model including hip abduction, ankle plantar flexion, trunk flexion, and knee flexion explained 57% of the adjusted variance in the T25FW; hip abduction, ankle plantar flexion, and trunk flexion explained 61% of the adjusted variance in the 6MWT. The strongest predictors were ankle plantar flexion endurance for the T25FW and hip abduction strength for the 6MWT: a 1-SD increase in ankle plantar flexion (15.2 heel-raise repetitions) was associated with a 0.33-second reduction in the T25WT (95% CI = - 0.71 to - 0.14 seconds); a 1-SD increase in normalized hip abduction strength (0.14 kg/body mass index) was associated with a 54.4-m increase in the 6MWT (28.99 to 79.81 m).

LIMITATIONS

Different measurement scales for independent variables were included because the muscle function assessment used either force or endurance.

CONCLUSIONS

For the major muscles in the lower extremity and trunk, hip abduction, ankle plantar flexion, trunk flexion, and knee flexion were the strongest predictors of gait performance.

Therapies for mobility disability in persons with multiple sclerosis

INTRODUCTION

Mobility disability is one of the most widespread and impactful consequences of multiple sclerosis (MS). Disease modifying drugs (DMDs) may delay the progression of disability over time; however, there is minimal evidence supporting the efficacy of DMDs for reversing mobility disability or restoring ambulatory function in persons with MS. Areas covered: This review outlines symptomatic pharmacologic and non-pharmacologic therapeutic approaches that target mobility disability with the goal of restoring and improving walking function. First, the efficacy of dalfampridine, currently the only Food and Drug Administration approved symptomatic pharmacologic agent that improves walking in persons with MS is described. Next, a review of the efficacy of non-pharmacologic therapies for improving walking, including exercise training, physical therapy, and gait training is given. Last, guidance on future research on mobility in MS is provided by emphasizing the importance of combinatory treatment approaches that include multiple intervention modalities, as the best treatment plan likely involves a comprehensive, multidisciplinary approach. Expert commentary: There has been an increased effort to develop symptom-specific treatments in MS that directly target mobility disability; however, more research is needed to determine the efficacy of these rehabilitative strategies alone and together for improving walking in persons with MS.

Effects of Muscle Function and Limb Loading Asymmetries on Gait and Balance in People With Multiple Sclerosis

People with MS (PwMS) often have a more- and less-affected side of the body which results in a variety of asymmetries, including measures of power, strength, muscle activity, and limb loading. Though many studies have identified asymmetries, their impact on gait and balance in PwMS is currently unclear. In this mini-review we first summarize previous findings of asymmetries in muscle function and limb loading and their impact on gait and balance in PwMS. We then provide potential explanations for this lack of consistency in the current literature, and propose study guidelines to improve future lower limb asymmetry studies. Making use of a unified approach to study lower limb asymmetry may then provide more clarity regarding their impact on mobility, specifically gait and balance, in PwMS.

The association between gait and physical fitness in adults with intellectual disabilities

BACKGROUND

Gait deviations are often seen in adults with intellectual disabilities (ID). Their low physical fitness levels may be associated with these deviations. Understanding the impact of fitness on gait in this population is important for developing interventions to improve gait. In a cross-sectional study, we assessed the association between multiple physical fitness components and spatiotemporal gait parameters in adults with ID.

METHOD

Gait characteristics of 31 adults (42.77 ± 16.70 years) with ID without Down syndrome were assessed with the GAITRite at comfortable (CS) and fast speed (FS), along with fitness assessments (body composition, muscular endurance, strength, balance, Short Physical Performance Battery).

RESULTS

At CS, adults with ID with higher BMI and/or waist circumference spent more time in double support. At FS, those with better muscular endurance took steps faster, those with better balance took bigger steps and strides and those with better Short Physical Performance Battery scores took bigger steps and strides at higher velocity.

CONCLUSIONS

Body composition was mostly associated with gait at CS, while the other physical fitness components were mostly associated with gait at FS. Better fitness may therefore be more important in more challenging conditions. These insights are useful for developing interventions to improve gait in adults with ID.

Exploring Wellness Interventions in Progressive Multiple Sclerosis: an Evidence-Based Review

PURPOSE OF REVIEW

There has been recent interest in the role of lifestyle and wellness-based approaches in the treatment and management of multiple sclerosis (MS). These approaches may be particularly relevant for patients with progressive MS, considering limited therapeutic options currently available. The purpose of this review is to examine the role of wellness-based interventions including exercise training, emotional well-being therapies, and dietary modification in patients with progressive MS.

RECENT FINDINGS

We conducted a literature search on the efficacy of wellness-based interventions in patients with progressive MS published between 1985 and July 2017. The level of evidence for each trial was evaluated using the American Academy of Neurology criteria. Overall, 21 articles reporting on 16 wellness-based interventions were identified: ten trials involved exercise training, three involved emotional wellness therapies, two involved dietary modification, and one was a combined wellness intervention. There is level C evidence (possibly effective; one class II study) for the efficacy of aerobic exercise training on cardiorespiratory fitness in patients with progressive MS. There is level B evidence (probably effective; one class I study) for the efficacy of mindfulness training on psychological distress, depression, anxiety, pain, and quality of life in patients with progressive MS. There is inadequate evidence (level U) for efficacy of dietary modification (one class III study and one class IV study) and combined wellness interventions involving exercise training, meditation, and dietary modification (one class IV study). High-quality research is needed to provide evidence-based recommendations for wellness behaviors and lifestyle change in patients with progressive MS.

Fatigue, as measured using the Modified Fatigue Impact Scale, is a predictor of processing speed improvement induced by exercise in patients with multiple sclerosis: data from a randomized controlled trial

BACKGROUND

Few studies have evaluated the impact of physical activity (PA) on cognition and fatigue, and none have considered the effects of PA on the relationship between cognition and fatigue.

OBJECTIVES

We evaluated the effect of PA in people with multiple sclerosis (pwMS) in a 6-month-long single-blind randomized controlled trial. We focused on the impact of exercise on cognition, fatigue, and the relationship between cognition and fatigue.

METHODS

We recruited pwMS, who were then randomly assigned 1:1 to either a PA protocol group or a control group (CG). All patients underwent assessments using the Brief International Cognitive Assessment for Multiple Sclerosis including symbol digit modality test (SDMT), Berg Balance Scale (BBS), gait analysis, 6-Minute Walk Test, Timed Up and Go (TUG) test, and the Modified Fatigue Impact Scale (MFIS) at the beginning of the study (T0), at the end of the study (EOS) 24 weeks after T0, and at 24 weeks following the EOS (FU).

RESULTS

A Wilcoxon test revealed a significant effect of exercise in the PA group, but not in the CG. Significant differences between T0 and EOS were found in the spatiotemporal parameters of gait, and performance on the SDMT, TUG, BBS, and MFIS. These differences were also present during the FU period. A regression model revealed that the baseline MFIS score predicted processing speed improvement (R² = 0.65, p < 0.01), as the SDMT T score increased by 0.3 for each one-unit increase in the MFIS score at T0.

CONCLUSION

PA affects multiple aspects of the pathology in pwMS. Patients with greater fatigue must not be discouraged from exercise, as they may greatly benefit from PA. Specifically, PA was shown to improve information processing speed.

Postural control deficits in people with Multiple Sclerosis: A systematic review and meta-analysis

BACKGROUND

Multiple sclerosis (MS) is a neurological condition that can affect the postural stability of the individual and predispose falls in this population.

METHODS

A systematic literature search identified case-control studies investigating differences in postural control across a diversity of task conditions, with the exception of gait, between people with MS and healthy controls. Meta-analysis was conducted where a variable was presented by four or more studies.

RESULTS

Forty-three studies of people with a mean Expanded Disability Status Scale (EDSS) of 1.0 to 6.0 were included. Seven conditions of assessment and 105 individual measurement variables relating to postural control were included. Quiet stance was the only condition (11 studies) possessing sufficient data to contribute to meta-analysis in terms of centre of pressure path length (SMD = 1.04, 95% CI {0.86-1.22}, p < 0.001), medio-lateral velocity (SMD = 1.35, 95% CI {0.77-1.92}, p < 0.001) and 95% confidence ellipse (SMD = 0.83 95% CI {0.59-1.08}, p < 0.001).

RESULTS

indicate that regardless of task complexity or sensory condition, people with MS display considerable deficits in postural control in comparison to healthy controls.

CONCLUSIONS

The large number of variables and lack of standardisation of reporting makes data synthesis challenging, however, people with MS display considerable deficits in postural control compared to healthy controls regardless of task condition or complexity.

Knee flexor strength and balance control impairment may explain declines during prolonged walking in women with mild multiple sclerosis

BACKGROUND

Physiological factors such as muscle weakness and balance could explain declines in walking distance by multiple sclerosis (MS) patients. The purpose of this study was to characterize levels and examine associations among decline in walking distance, balance and muscular strength in women with mild MS.

METHODS

Participants included 28 women with mild relapsing-remitting MS and 21 women without MS. We executed the 6-min walk test (6MWT) to verify declines in walking distance. Isokinetic knee flexion (KF) and extension (KE) muscle strength was measured using a dynamometer. Balance was quantified using a force platform, with eyes open and closed, on a rigid and foam surface.

RESULTS

The MS patients presented declines in walking, lower KF muscle strength, and worse balance than controls. KF strength and balance correlated with walking in the MS group. The KF strength explained differences between groups in walking. The KF strength and balance presented as predictors of walking slowing down in the 6MWT, in mild MS.

CONCLUSION

Women with mild MS have strength impairment of knee flexor muscles and balance control impairment that may explain walking related motor fatigability during prolonged walking.

Pulse Width Does Not Influence the Gains Achieved With Neuromuscular Electrical Stimulation in People With Multiple Sclerosis: Double-Blind, Randomized Trial

BACKGROUND

Multiple sclerosis (MS) eventually compromises the walking ability of most individuals burdened with the disease. Treatment with neuromuscular electrical stimulation (NMES) can restore some functional abilities in persons with MS, but its effectiveness may depend on stimulus-pulse duration.

OBJECTIVE

To compare the effects of a 6-week intervention with narrow- or wide-pulse NMES on walking performance, neuromuscular function, and disability status of persons with relapsing-remitting MS.

METHODS

Individuals with MS (52.6 ± 7.4 years) were randomly assigned to either the narrow-pulse (n = 13) or wide-pulse (n = 14) group. The NMES intervention was performed on the dorsiflexor and plantar flexor muscles of both legs (10 minutes each muscle, 4 s on and 12 s off) at a tolerable level for 18 sessions across 6 weeks. Outcomes were obtained before (week 0) and after (week 7) the intervention and 4 weeks later (week 11).

RESULTS

There was no influence of stimulus-pulse duration on the outcomes ( P > .05); thus, the data were collapsed across groups. The NMES intervention improved ( P < .05) gait speed and walking endurance, dorsiflexor strength in the more-affected leg, plantar flexor strength in the less-affected leg, force control for plantar flexors in the less-affected leg, and self-reported levels of fatigue and walking limitations.

CONCLUSION

There was no influence of stimulus-pulse duration on the primary outcomes (gait speed and walking endurance). The 6-week NMES intervention applied to the lower leg muscles of persons with mild to moderate levels of disability can improve their walking performance and provide some symptom relief.