Maximal strength training fatigue and balance in multiple sclerosis
- Autores: Ramón Gómez Illán
- Directores de la Tesis: Francisco J. Vera García (dir. tes.), Raúl Reina Vaíllo (dir. tes.)
- Lectura: En la Universidad Miguel Hernández de Elche ( España ) en 2017
- Idioma: inglés
- Tribunal Calificador de la Tesis: Nuria Mendoza Laíz (presid.), José Manuel Sarabia Marin (secret.), Angel Constantino Pérez Sempere (voc.), Juan Tortosa Martínez (voc.), Carlos Medina Pérez (voc.)
- Materias:
- Enlaces
- Tesis en acceso abierto en: RediUMH (pdf)
- Resumen
Multiple sclerosis (MS) is a chronic and progressive autoimmune disease, being the main cause of disability in young adults after traffic accidents. During the last years, the scientific literature has established that a better physical condition implies a better general state of the person who suffers MS, including a better cardiovascular health, reduced fatigue, improved balance and lower risk of falls, among others, leading to an improvement of the quality of life.
Several researches have attempted to improve some of the symptoms that this pathology entails through physical exercise. Although it has been found that a better fitness condition would imply a higher quality of life, there is interest in establishing what type of exercise could be the best to improve each symptom. The heterogeneity of people with MS who participate in studies of physical exercise and quality of life makes the research in this population a complex issue.
One of the symptoms that patients perceive as one of the most disabling is the loss of stability. It is common that people with MS, in the course of the disease, suffer problems with postural control, increasing the risk of falls that can lead to bone fractures and other clinical complications. Postural control is a complex action that depends on the contribution of the sensory system (i.e. visual, vestibular and somatosensory), the motor system (e.g. force production, especially in the trunk and the lower body, and bilateral asymmetries) and perceived fatigue. Improving postural control is one of the main objectives of rehabilitation programs for people with MS and, therefore, many studies have tried to establish which exercises would be most suitable for this purpose. Thus, one of the main objectives of Study 1 of this Doctoral Thesis was to explore the main factors that influence the loss of stability in people with MS.
Many of the tests that measure the degree of stability in people with MS come from the clinical scope, sometimes lacking an adequate analysis of their reliability. In this sense, another of the main objectives of Study 1 of this Doctoral Thesis was to design a protocol that allows assessing the stability in a reliable and precise way. In this study we have assessed the relative and absolute reliability of a stability test battery, both in the upright and the sitting position, by using a force platform and the analysis of the centre of pressure pathway. In addition, the results of the postural control tests applied in the laboratory were related to other clinical and field tests widely used to measure functional mobility and gait performance in this population (Timed Up and Go Test and Timed 25-foot Walk Test), to determine if a better postural control implies a better walking performance in people with MS. The results show that the proposed postural control tests, both in tandem and in sitting position, show relative reliability values between high and excellent, as well as good absolute reliability. These data indicate that these tests allow to discriminate the degree of stability in people with minimal symptoms, such as those with a moderate condition, and, moreover, to verify the effect of different interventions for the improvement of stability. The data of the correlations suggest that trunk stability can influence general stability and, therefore, become a variable to be trained to improve postural control, which has an influence on the quality of life of these individuals.
Study 2 of this Doctoral Thesis addressed two of the three factors that influence the lack of stability in persons with MS: muscle weakness (i.e. lack of force production) and perceived fatigue, being its main objective to reduce perceived fatigue in people with MS through participation in a maximum strength training.
Previous studies suggest that strength training at high intensities improves neural transmission and reduces the level of pro-inflammatory cytokines, thus contributing to a reduction in fatigue. In this study, a group of people with MS participated in a 12-week intervention program, consisting of a high-intensity strength training, reaching intensities considered as maximum strength (90% of 1 maximum repetition). The results show that perceived fatigue evaluated with the Fatigue Severity Scale and the Modified Fatigue Impact Scale reduced significantly after the training program. In addition, this program reduced the time taken to perform the Timed Up and Go Test significantly, one of the most commonly used functional tests used to verify functional mobility in people with MS. A correlation analysis also shows how a lower body strength increase was related to both a perceived fatigue decrease and a gait test performance improvement.
Findings of this Doctoral Thesis may help rehabilitation teams that work with people with MS to assess postural control in a reliable and precise way. In this sense, the stability test battery may help to categorize persons with MS according to performance in the proposed tests and, subsequently, to evaluate the results of possible interventions aimed to improve stability. On the other hand, the strength training program analysed in this study may be used as a basis for future research to design larger interventions to verify that maximum strength training can reduce perceived fatigue in people with MS.
