The Association of Age, Sex, and BMI on Lower Limb Neuromuscular and Muscle Mechanical Function in People with Multiple Sclerosis

(1) Background: The countermovement jump (CMJ) on a force plate could be a sensitive assessment for detecting early lower-limb muscle mechanical deficits in the early stages of multiple sclerosis (MS). CMJ performance is known to be influenced by various anthropometric, physiological, and biomechanical factors, mostly investigated in children and adult athletes. Our aim was to investigate the association of age, sex, and BMI with muscle mechanical function using CMJ to provide a comprehensive overview of lower-limb motor function in people with multiple sclerosis (pwMS). (2) Methods: A cross-sectional study was conducted with pwMS (N = 164) and healthy controls (N = 98). All participants performed three maximal CMJs on a force plate. Age, sex, and BMI were collected from all participants. (3) Results: Significant age, sex, and BMI effects were found for all performance parameters, flight time, and negative and positive power for pwMS and HC, but no significant interaction effects with the group (pwMS, HC) were detected. The highest significant effects were found for sex on flight time (η2 = 0.23), jump height (η2 = 0.23), and positive power (η2 = 0.13). PwMS showed significantly lower CMJ performance compared to HC in middle-aged (31-49 years), with normal weight to overweight and in both women and men. (4) Conclusions: This study showed that age, sex, and BMI are associated with muscle mechanical function in pwMS and HC. These results may be useful in developing reference values for CMJ. This is a crucial step in integrating CMJ into the diagnostic assessment of people with early MS and developing individualized and effective neurorehabilitative therapy.

Multimodal exercise training to reduce frailty in people with multiple sclerosis: study protocol for a pilot randomized controlled trial

BACKGROUND

Frailty, a syndrome characterized by decreased reserve and resistance to stressors across multiple physiologic systems, is highly prevalent in people living with multiple sclerosis (pwMS), independent of age or disability level. Frailty in MS is strongly associated with adverse clinical outcomes, such as falls, and may aggravate MS-related symptoms. Consequently, there is a pressing necessity to explore and evaluate strategies to reduce frailty levels in pwMS. The purpose of this pilot randomized controlled trial (RCT) will be to examine the feasibility and preliminary efficacy of a multimodal exercise training program to reduce frailty in pwMS.

METHODS

A total of 24 participants will be randomly assigned to 6 weeks of multimodal exercise or to a waitlist control group with a 1:1 allocation. PwMS aged 40-65 years and living with frailty will be eligible. The multimodal exercise program will consist of cognitive-motor rehabilitation (i.e., virtual reality treadmill training) combined with progressive, evidence-based resistance training. At baseline and post-intervention, participants will complete the Evaluative Frailty Index for Physical Activity (EFIP), measures of fall risk, and quality of life. Frailty-related biomarkers will also be assessed. In addition, the feasibility of the multimodal exercise program will be systematically and multidimensionally evaluated.

DISCUSSION

To date, no RCT has yet been conducted to evaluate whether targeted exercise interventions can minimize frailty in MS. The current study will provide novel data on the feasibility and preliminary efficacy of multimodal exercise training as a strategy for counteracting frailty in pwMS.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT06042244 (registered in September 2023).

Pumping up the Fight against Multiple Sclerosis: The Effects of High-Intensity Resistance Training on Functional Capacity, Muscle Mass, and Axonal Damage

BACKGROUND

Resistance training (RT) has been recognized as a beneficial non-pharmacological intervention for multiple sclerosis (MS) patients, but its impact on neurodegeneration is not fully understood. This study aimed to investigate the effects of high-intensity RT on muscle mass, strength, functional capacity, and axonal damage in MS patients.

METHODS

Eleven relapsing-remitting MS patients volunteered in this within-subject counterbalanced intervention study. Serum neurofilament light-chain (NfL) concentration, vastus lateralis thickness (VL), timed up-and-go test (TUG), sit-to-stand test (60STS), and maximal voluntary isometric contraction (MVIC) were measured before and after intervention. Participants performed 18 sessions of high-intensity RT (70-80% 1-RM) over 6 weeks.

RESULTS

Significant (p < 0.05) differences were observed post-intervention for VL (ES = 2.15), TUG (ES = 1.98), 60STS (ES = 1.70), MVIC (ES = 1.78), and NfL (ES = 1.43). Although moderate correlations between changes in VL (R = 0.434), TUG (R = -0.536), and MVIC (R = 0.477) and changes in NfL were observed, only the correlation between VL and MVIC changes was significant (R = 0.684, p = 0.029).

CONCLUSIONS

A 6-week RT program significantly increased muscle mass, functional capacity, and neuromuscular function while also decreasing serum NfL in MS patients. These results suggest the effectiveness of RT as a non-pharmacological approach to mitigate neurodegeneration while improving functional capacity in MS patients.

The MoxFo initiative - outcomes: Outcome measures in studies of exercise training in multiple sclerosis; scoping review of reviews and classification according to the ICF framework

BACKGROUND

The number of published studies of exercise training in multiple sclerosis (MS) has grown exponentially with increasing numbers of outcomes capturing exercise effects. This has complicated the selection of relevant indicators and interpretation of intervention effects.

OBJECTIVES

The Outcomes subgroup of the MoXFo initiative aimed to (1) identify outcome measures and biomarkers in studies of exercise training in MS; (2) systematically map retrieved outcomes to International Classification of Functioning, Disability and Health (ICF) categories; (3) identify gaps where relevant ICF categories have been omitted.

METHODS

Electronic databases and registers were searched from 2010 to July 2020 to identify systematic reviews or meta-analyses of controlled trials of exercise training on any outcome in MS. Retrieved outcomes/biomarkers were mapped to the corresponding ICF category.

RESULTS

Eighty-one review articles reporting 235 different outcomes were included. The outcomes corresponded to 15 chapters and 45 categories within the ICF. Outcomes mapped primarily to body function (30 categories) and activities and participation (9 categories) components. Few outcomes mapped to body structures (2 categories) or environmental factors (1 category).

CONCLUSION

This sets the stage to develop a resource for researchers/clinicians that will aid in the selection of appropriate outcomes/biomarkers when examining exercise effects in MS.

Effect of different types of exercise on fitness in people with multiple sclerosis: A network meta-analysis

BACKGROUND

It is assumed that people with multiple sclerosis (MS) who participate in programs of physical exercise improve their physical fitness.

OBJECTIVE

The aim of this network meta-analysis (NMA) was to analyze the effect of different types of exercise on muscular fitness and cardiorespiratory fitness (CRF) among people with MS and to determine the best type of exercise according to disease severity.

METHODS

MEDLINE, the Physiotherapy Evidence Database, the Cochrane Library, SPORTDiscus, Scopus, and Web of Science were searched from inception to April 2022 to identify randomized controlled trials (RCTs) concerning the effect of physical exercise on fitness in people with MS. We ranked the types of physical exercise by calculating the surface under the cumulative ranking (SUCRA).

RESULTS

We included 72 RCTs involving 2543 MS patients in this NMA. A ranking of five types of physical exercise (aerobic, resistance, combined [aerobic and resistance], sensorimotor training, and mind-body exercises) was achieved. Combined and resistance training had the highest effect sizes (0.94, 95% CI 0.47, 1.41, and 0.93, 95% CI 0.57, 1.29, respectively) and the highest SUCRA (86.2% and 87.0%, respectively) for muscular fitness. The highest effect size (0.66, 95% CI 0.34, 0.99) and SUCRA (86.9%) for CRF was for aerobic exercise.

CONCLUSIONS

Combined and resistance training seem to be the most effective exercises to improve muscular fitness and aerobic exercise for CRF in people with MS.

Exploring the impact of exercise and essential amino acid plus cholecalciferol supplementation on physical fitness and body composition in multiple sclerosis: A case study

Key Clinical Message

In MS patients, especially those frail or malnourished, combining home-based exercise twice weekly with essential amino acids and vitamin D may improve body composition, strength, and physical performance, enabling long-term functional improvements.

Abstract

Multiple sclerosis (MS) is associated with reduced bone and muscle strength and function. We aimed to investigate the effectiveness of a 24-week intervention in a 57-year-old frail female with MS. The participant completed a 2×/week exercise intervention and ingested 2×/day a supplement containing 7.5 g essential amino acids and 500 IU cholecalciferol. Body composition, 6-m gait speed (GS), handgrip strength (HGS), 30-sec arm-curl test (30ACT), 6-min walking test (6MWT), 30-sec chair-stand test (30CST), and plasma concentrations of 25-hydroxyvitamin D₃ [25(OH)D₃], insulin-like growth factor 1 (IGF-1), and amino acids were assessed at baseline, and at Weeks 12 and 24. Plasma 25(OH)D₃ increased from 23.2 to 41.3 ng/mL and IGF-1 from 131.6 to 140.7 ng/mL from baseline to post-intervention. BMI, total lean tissue mass (LTM), fat mass, bone mineral content, and the sum of 17 amino acids increased by 3.8, 1.0, 3.5, 0.2, and 19%, respectively, at Week 24. There were clinically significant increases in regional LTM (6.9% arms and 6.3% legs) and large increases in GS (67.3%), dominant HGS (31.5%), non-dominant HGS (11.8%), dominant 30ACT (100%), non-dominant 30ACT (116.7%), 6MWT (125.6%), and 30CST (44.4%). The current intervention was effective in improving components of physical fitness and body composition in a female with MS.

The impact of aerobic and resistance training intensity on markers of neuroplasticity in health and disease

OBJECTIVE

To determine the effects of low- vs. high-intensity aerobic and resistance training on motor and cognitive function, brain activation, brain structure, and neurochemical markers of neuroplasticity and the association thereof in healthy young and older adults and in patients with multiple sclerosis, Parkinson's disease, and stroke.

DESIGN

Systematic review and robust variance estimation meta-analysis with meta-regression.

DATA SOURCES

Systematic search of MEDLINE, Web of Science, and CINAHL databases.

RESULTS

Fifty studies with 60 intervention arms and 2283 in-analyses participants were included. Due to the low number of studies, the three patient groups were combined and analyzed as a single group. Overall, low- (g=0.19, p = 0.024) and high-intensity exercise (g=0.40, p = 0.001) improved neuroplasticity. Exercise intensity scaled with neuroplasticity only in healthy young adults but not in healthy older adults or patient groups. Exercise-induced improvements in neuroplasticity were associated with changes in motor but not cognitive outcomes.

CONCLUSION

Exercise intensity is an important variable to dose and individualize the exercise stimulus for healthy young individuals but not necessarily for healthy older adults and neurological patients. This conclusion warrants caution because studies are needed that directly compare the effects of low- vs. high-intensity exercise on neuroplasticity to determine if such changes are mechanistically and incrementally linked to improved cognition and motor function.

Strength training for people with multiple sclerosis and the current recommendations

Recent guidelines recommend strength and conditioning training for patients with multiple sclerosis (MS). This article evaluates and summarises four systematic reviews examining strength training for people with MS and examines if these reviews substantiate these current guidelines.

Effective rehabilitation interventions and participation among people with multiple sclerosis: an overview of reviews

BACKGROUND

Multiple sclerosis (MS) is the most common cause of non-traumatic disability in people aged 10 to 65 years. Evidence exists for the effectiveness of multidisciplinary rehabilitation and exercise. However, the effectiveness of other rehabilitation approaches in MS needs further evaluation.

OBJECTIVE

We aimed to systematically synthesize and evaluate knowledge on effectiveness of rehabilitation interventions and determinants for participation among people with MS (pwMS) to inform clinical guidelines on rehabilitation.

METHODS

Joanna Briggs Institute methodology was used. PubMed, Embase, CINAHL, PsycINFO and Web of Science were searched for reviews, systematic reviews, meta-analyses, and meta-syntheses published during 2009-2019. All types of rehabilitation interventions provided to pwMS at any time and in all settings were eligible. Two reviewers independently screened and extracted data. The most recently published reviews on mixed and specific modalities were included. The findings were reported in a narrative summary and a mixed-methods analysis.

RESULTS

Among 108 eligible reviews, 6 qualitative or mixed-methods reviews and 66 quantitative reviews were included (total pwMS >90,000). This overview provides solid evidence for the effectiveness of a spectrum of modalities. Among the modalities, there was strong evidence for the effectiveness of multidisciplinary, cognitive and exercise approaches, physiotherapy, and occupational therapy, including full body training on functioning, and participation outcomes. Employment significantly affected quality of life; thus, vocational rehabilitation should be initiated early. Healthcare professionals should identify personal factors including relations and coping, and the rehabilitation process should involve partners or close family.

CONCLUSIONS

The mixed-methods analysis revealed insufficient consensus between the perspectives of pwMS on their rehabilitation and reported effects, indicating that further research should target the experiences of pwMS. Furthermore, rehabilitation should be patient-centred, focus on the complexity of needs, and be organised and performed by an experienced multidisciplinary team. Evidence-based rehabilitation should be initiated early after pwMS are diagnosed and follow international guidelines. Database registration. PROSPERO ID (CRD42020152422).

Functional relevance of resistance training-induced neuroplasticity in health and disease

Repetitive, monotonic, and effortful voluntary muscle contractions performed for just a few weeks, i.e., resistance training, can substantially increase maximal voluntary force in the practiced task and can also increase gross motor performance. The increase in motor performance is often accompanied by neuroplastic adaptations in the central nervous system. While historical data assigned functional relevance to such adaptations induced by resistance training, this claim has not yet been systematically and critically examined in the context of motor performance across the lifespan in health and disease. A review of muscle activation, brain and peripheral nerve stimulation, and imaging data revealed that increases in motor performance and neuroplasticity tend to be uncoupled, making a mechanistic link between neuroplasticity and motor performance inconclusive. We recommend new approaches, including causal mediation analytical and hypothesis-driven models to substantiate the functional relevance of resistance training-induced neuroplasticity in the improvements of gross motor function across the lifespan in health and disease.

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.

Contralateral Strength Training as Preparation for Direct Strength Training in a Patient With Unilateral Foot-Drop Because of Multiple Sclerosis: A Case Report

OBJECTIVE

Direct strength training (DST) is effective in managing unilateral weakness in people with multiple sclerosis (MS). Its feasibility, however, is considerably reduced if one limb is too compromised to train. In this case, contralateral strength training (CST) of the unaffected side to induce a strength transfer to the untrained homologous muscles can help to establish a strength baseline in the weaker limb, eventually allowing direct training. Limited effects for CST, however, have been reported on patient functioning. We tested the effects on dynamometric, electromyographic, and functional outcomes of a sequential combination of CST and DST of the ankle dorsiflexors in a case of MS-related foot-drop.

METHODS

A 56-year-old man diagnosed with relapsing-remitting MS exhibited severe weakness of the right dorsiflexors impairing functional dorsiflexion. The intervention consisted of a 6-week CST of the unaffected dorsiflexors followed by 2 consecutive 6-week DST cycles targeting the weaker dorsiflexors.

RESULTS

At baseline, the participant could not dorsiflex his right ankle but could do so after CST. Maximal strength of the affected dorsiflexors increased by 80% following CST, by 31.1% following DST-1, and by a further 44.6% after DST-2. Neuromuscular recruitment was found progressively increased, with the largest changes occurring after DST-1. Improvements in mobility and walking speed were also detected, although plantar flexors' spasticity on the Modified Ashworth Scale increased from 1+ to 2.

CONCLUSION

In this case, the sequential combination of CST and DST proved a feasible approach to manage severe unilateral weakness in a patient who was not able, at least initially, to dorsiflex his weaker ankle. In this perspective, CST may prime a minimum gain in strength necessary to allow subsequent direct training.