Assessment of Changes in Postural Stability and Load Distribution in Patients With Multiple Sclerosis After 12 Weeks of Self-Paced Exercises Programmed by a Physiotherapist: A Prospective Cohort Study

Introduction

Multiple sclerosis (MS) is a chronic, progressive disease of the central nervous system (CNS) with an unclear etiology [1]. The disease progression involves an inflammatory process leading to demyelination and is characterized by periods of relapse and remission, with multifocal CNS damage leading to functional limitations, including hypokinesia. Studies of patients with MS have demonstrated reduced muscle strength during dynamic [2,3] and static [2,4] contractions, with deficits mainly affecting the lower limbs [4,5]. Approximately 75% of patients with MS experience walking and balance limitations, and the reported fall rate is about 56% [6]. The mechanisms underlying reduced muscle strength are likely to be of both muscular and neural origin. The results of some studies have shown a loss of muscle mass, which may lead to a relative decrease in muscle strength [7]. Similarly, the results concerning the distribution of muscle fiber types in patients with MS and healthy individuals are inconclusive.

Although many symptomatic and disease-modifying therapies are available, they do not prevent progressive disability; therefore, new treatments are still needed, particularly for progressive MS. Current approaches include monoclonal antibodies, cell-based therapies, such as chimeric antigen receptor T-cell therapy, and strategies targeting microglia and ferroptosis. Additional emerging options focus on microbiota-directed interventions and dietary modification [8]. In this context, rehabilitation with the use of physical activity is an important therapeutic aspect to alleviate the symptoms of the disease and reduce disability, thereby supporting patients’ independence in their daily functioning [9]. In the case of MS, moderate physical activity is recommended [10]. The effectiveness of combining resistance exercises with a dominant aerobic component in improving walking ability and increasing muscle strength has also been demonstrated. The effectiveness of progressive resistance training has also been confirmed [5,11].

The specific features of MS – the young age of patients, variety of symptoms, unpredictable course, and unknown etiology – all make the rehabilitation of patients a difficult issue [12]. In this context, the most essential element of individualized rehabilitation is tailored to the disease stage and to the real needs of the patient [13], enabling their participation in this process. In our research, we propose a systematic, individualized program of self-paced exercises that lead to functional improvements in the lower limbs. The aim of this study was to assess the changes that occurred in the selected functional parameters of patients with MS after 12 weeks of self-paced, individualized exercises designed by a physiotherapist.

Material and Methods

SAMPLE AND DATA COLLECTION:

This study was an exploratory prospective cohort and non-controlled study. The study included 24 women, with an average age of 36.8 years, with similar symptoms and cognitive function. The inclusion criteria for the study were diagnosis of MS made by a physician, written consent of the patient to participate in the study, cognitive function status score (Mini-Mental State Examination) over 27, disease remission time of at least 6 months, independence of movement score of 0 to 6 points on the Expanded Disability Status Scale (EDSS), and not undergoing any other form of rehabilitation at the same time.

Only women were enrolled in the study, to ensure homogeneity of the study group and to limit the influence of sex-related biological and hormonal factors that may modify responses to physical effort and rehabilitation interventions [14]. Sex differences in the course of MS and in responses to exercise training have been widely documented [15,16]. Women constitute most MS cases, and their response to exercise programs can differ from that of men due to differences in physiology, sex hormone levels, and patterns of physical activity, which may affect the functional and immunological outcomes of rehabilitation. Previous clinical studies and literature reviews emphasize that variability in training responses between women and men can be an important confounding factor when interpreting results in small samples, which justified focusing this analysis on a homogeneous female cohort to minimize sex-related variability and improve the validity of the findings [17]. This approach enabled a more precise assessment of the feasibility and tolerability of the implemented exercise program in women with MS, while also providing a basis for future studies that will include male participants.

Patients were excluded from the study if they had experienced a disease relapse within the previous 6 months or if they were simultaneously participating in other forms of rehabilitation that could affect the results. Additional exclusion criteria included EDSS score >6, lack of written informed consent to participate, unstable hemodynamic parameters, and diagnosed mental disorders treated pharmacologically, which could limit the ability to participate safely in the exercise program and compromise the reliability of the collected data.

All patients underwent a 12-week self-administered program of exercises to strengthen the functional parameters of the lower limbs that was developed individually by our team for each patient. Each patient had 1 session with the same physiotherapist and was subjected to an initial assessment of lower limb functional parameters (Tables 1–3). The intervention was self-administered, with limited objective adherence monitoring; however, this reflects real-world clinical practice and provides practical, clinically relevant information for physiotherapists. The same measurement procedure was repeated at the end of the 12-week cycle. Patients were recommended to perform an individual set of exercises at least once a day for 45 minutes, according to a standard algorithm (10 minutes of warm-up, 25 minutes of proper exercise, and 10 minutes of stretching and breathing exercises) for 5 days a week. The sessions included a series of 6 to 10 exercises targeting the main muscle groups, performed in 1 to 3 sets of 8 to 15 repetitions, depending on the patient’s capacity. Resistance intensity was individually adjusted, starting with lower-resistance TheraBand bands (yellow/red) and progressively increasing to higher-resistance bands (green/blue or higher) as strength and training tolerance improved. The selection of band color and degree of stretch was based on the patient’s ability to complete the prescribed number of repetitions while maintaining proper technique. This study included the results of 24 women who stated that they had complied with the exercise algorithm for 12 weeks. Additionally, patients were required to maintain an exercise diary documenting adherence to the prescribed program, including completion of the planned exercises and the number of sets performed. They also remained in regular contact with the physiotherapist throughout the intervention period.

Our study was approved by the University Senate Research Bioethics Committee, University School of Physical Education, Wrocław (case No. 13/2020), and was conducted in accordance with the Code of Ethics of the World Medical Association for experiments involving humans (the Declaration of Helsinki).

PHYSICAL ACTIVITY PROTOCOL:

The program called for exercising 45 minutes a day (5 days a week, excluding weekends) at a moderate perceived fatigue level (equivalent to approximately 65% VO₂max), including a warm-up of approximately 5 to 10 minutes, a main section of exercises lasting approximately 25 minutes, and a 10-minute final part consisting of stretching and breathing exercises. It was also recommended to avoid overheating the body because of the risk of causing conduction disturbances and exacerbating fatigue symptoms.

The main exercise section aimed to improve the strength and endurance of the lower limbs. It included the following 5 parts: (1) exercises using external resistance and depending on the maximum strength, using resistance bands, in several sets of repetitions for the main muscle groups; (2) equilibrium exercises in the supported kneeling position and in the sitting position, using a sensory pillow; (3) isometric exercises; (4) elements of coordination and balance exercises; and (5) elements of exercises focused on the loading and work-controlling phases of the quadriceps muscle. When the patients experienced significant fatigue, they were advised to stop exercising and to rest, so as not to become overtired.

MEASURES OF FUNCTIONAL PARAMETERS:

Lower limb loading under static conditions was assessed using a pressure distribution measurement platform (Zebris Medical) equipped with 1504 sensors fixed on a surface of 320×470 mm, which allowed measurement of the pressure distribution under static and dynamic conditions.

The study included analysis of foot pressure distribution of both limbs – referred to as the dominant leg (DL) and nondominant leg (NDL) – as well as a balance test, in the course of a 60-second static test with eyes open and eyes closed. The load distribution of the left and right limbs, expressed in [%], and the location of the center of pressure (CoP) during the balance test were also considered.

The following CoP-related parameters were also considered in the balance assessment: the mean CoP in the x-direction (MCoCx); mean CoP in the y-direction (MCoCy); CoP sway path length (in centimeters) for 60 seconds; width of ellipse, which indicates the amplitude; height of ellipse; and area of ellipse. MCoCx was defined as the average mediolateral position of the CoP recorded during the measurements, reflecting the distribution of body weight along the left-right axis, while MCoCy was defined as the average anteroposterior position of the CoP recorded during the trial, reflecting the distribution of body weight along the anterior-posterior axis; both are expressed in centimeters.

During the test, the patient stood barefoot on a pressure distribution measurement platform with feet placed symmetrically and at equal distances from the center of the platform. The test was first performed with the eyes open, and then repeated with the eyes closed. The measurement was performed 3 times, and the results were averaged. DL was identified by having the patient juggle or kick a ball [18–20].

The data were analyzed using the SigmaPlot statistics package, version 13 (Systat Software, London, UK). Continuous variables were analyzed for normal distribution using the Shapiro-Wilk test. Data are expressed as means±standard deviations, as well as medians and 5th and 95th percentiles. Differences between dependent groups were examined using a paired t test or the Wilcoxon signed-rank test (for data that were not normally distributed). Differences between independent groups were examined using the unpaired t test or the Wilcoxon signed-rank test (before and after 12 weeks exercises program). The power of analysis (desired ≥80%) was calculated using the statistical module of the SigmaPlot software. Figures were prepared using Xact v 7.2 (SciLab, Hamburg, Germany). A P value <0.05 was considered statistically significant. The effect size was calculated by means of an online calculator: https://dissertationdataanalysishelp.com/cohens-d-calculator/. Cohen’s d is a standardized effect size measure that gives information about how meaningful the difference between groups is. The interpretation of Cohen’s d is d <0.2: very small; 0.2≤ d <0.5: small; 0.5≤ d <0.8: medium; and d ≥0.8: large [21].

Results

The study included 24 female patients with MS, with a mean age of 36.8±7.8 years and an average disease duration of 9.0±6.8 years. All patients completed the study.

Descriptive characteristics of the patients are presented in Table 4, and the EDSS values distribution in Figure 1. A median EDSS score of 0.0 shows that a substantial proportion of patients had no measurable disability. To clarify this finding, the distribution of EDSS scores is presented in Figure 1. Notably, 14 patients (58.3%) were classified as having no disability. We assessed body-weight distribution (BWD) and body-weight distribution asymmetry (BWDA) with open and closed eyes at baseline and after 12 weeks (Table 1, Figure 2). BWDA, calculated as the difference in percentage body weight load between the limbs, was assessed as the load difference between the limbs before and after rehabilitation (Figure 2). At baseline, we found statistically significant differences (P<0.001) in BWD between the DL and NDL, both with open eyes (54.8±2.6 vs 45.2±2.7) and closed eyes (57.2±2.7 vs 42.8±2.7). After 12 weeks of self-administered exercise, the distribution between DL and NDL showed improvement, with open eyes (51.9±1.1 vs 48.1±1.1) and closed eyes (53.0±1.1 vs 47.0±1.1), although the differences remained statistically significant (P<0.001). The effect size indicated a large magnitude of effect (Cohen’s d ≥0.8) and the power of analysis of over 0.8. We also observed positive changes in BWDA between baseline and after 12 weeks of the self-administered exercise program. BWDA was significantly lower after 12 weeks compared with baseline (P<0.001), both with open eyes (9.7±4.5 vs 3.8±2.1) and closed eyes (14.5±5.3 vs 5.9±2.2) (Figure 2).

Furthermore, we examined differences in balance parameters between baseline and after 12 weeks of exercise (Table 2; Figures 3, 4). Improvements were observed across all parameters for both open- and closed-eye conditions, including the MCoCx, MCoCy, sway path length, amplitude of CoP (width of ellipse), height of CoP (height of ellipse), and area of the ellipse. However, statistically significant changes were noted specifically in MCoCx (17.4±1.6 vs 16.3±1.0; P=0.005 [large effect size] and 17.4±1.4 vs 16.1±1.5; P<0.002 [large effect size]; Figure 3) and MCoCy (24.4±1.1 vs 22.6±1.5; P<0.001 and 24.2±1.6 vs 22.3±1.7; P<0.001; Figure 4). Table 3 presents the changes in limb load distribution between the DL and NDL before and after the exercise program (eyes open and closed). We observed statistically significant changes (P<0.001; d ≥0.8), indicating improved load symmetry. For DL, values changed from 54.8±2.6 to 51.9±1.1 (open eyes) and from 57.2±2.6 to 53.0±1.1 (closed eyes). Correspondingly, for the NDL, values increased from 45.2±2.6 to 48.1±1.1 (open eyes) and from 42.8±2.6 to 47.0±1.1 (closed eyes). The statistical analysis demonstrated significant improvements in limb load symmetry and selected CoP parameters, whereas the remaining balance measures did not reach statistical significance.

Discussion

LIMITATIONS:

Our study has some limitations, including the small sample size, lack of a control group, adherence based on self-report, analysis of multiple outcome parameters, and inclusion of only women with relatively low disability, which may limit the representativeness and generalizability of the findings. Because multiple outcomes were analyzed without formal correction for multiple comparisons, there is a potential risk of Type I error inflation. Although large effect sizes were observed for selected outcomes (Cohen’s d ≥0.8), these estimates may be influenced by the small sample size and within-subject design; therefore, the magnitude of effects should be interpreted cautiously and confirmed in larger controlled studies. The relatively small and homogeneous cohort reflects the need to enroll patients who met strict inclusion criteria and were able to complete the 12-week intervention protocol in a consistent manner.

A strong aspect of our study was the exercise algorithm tailored to the individual needs of each patient. Furthermore, we relied on the latest recommendations and guidelines for functional physiotherapy for patients with MS. Our study also confirms that it is possible to reduce healthcare expenses while encouraging patient participation in the prevention of dysfunctions and disorders. The research needs to be continued with a larger study group, and longer-term effects require further investigation and external validation in other populations. Finally, this study was not designed to test causality and functional outcomes, and the observed findings reflect associations rather than causal relationships.

Conclusions

After 12 weeks of self-paced exercises conducted among patients with MS, significantly improved lower limb loading symmetry and selected balance parameters were observed, both with eyes open and closed.