How Does Strength Training and Balance Training Affect Gait Function and Fatigue in Patients With Multiple Sclerosis?

People with MS experience a wide variety of symptoms including impaired muscle strength and balance, fatigue, impaired cognition, depression and spasticity. Of these, impaired balance and severe fatigue are described as two of the most debilitating symptoms leading to limitations in activities such as upright posture and gait. Generally, pharmacological symptomatic treatment has not proven efficient in the treatment of balance problems, fatigue and walking impairments, with the exception that Fampridine has beneficial effects on gait performance in a subgroup of patients. Consequently, non-pharmacological interventions that effectively target these symptoms are warranted.

In the last decade progressive resistance training (PRT) has proven to be one of the promising interventions in patients with MS showing a consistent and positive effect on muscle strength. However, the effect of PRT on functional outcomes are heterogeneous but with promising effects on daily activities such as walking and chair rise. The evidence for a beneficial effect of PRT on balance and postural control is divergent and yet inadequately investigated. Regarding fatigue, a recent Cochrane review reported that one could expect improvements in MS fatigue after exercise interventions, despite methodological flaws in the existing literature, but only few studies evaluating PRT were located.

Another promising intervention is task specific training of motor function that is widely used by physiotherapists in neurorehabilitation. In this study protocol, motor function is limited to gait related functions with a particular focus put on balance and motor control, why the term Balance and Motor Control Training (BMCT) is applied. There is no universally accepted definition of human balance, but balance defined as "the inherent ability of a person to maintain, achieve or restore a specific state of balance and not to fall, with reference to the motor and sensory systems and to the physical properties of the person", is applied in this study.

Effects obtained from BMCT partly result from plastic changes in the nervous system. To induce such effects, repetition of a simple task only has limited efficiency in order to improve performance. Once a task has been learned to a certain level, further practice of the same task will not be accompanied by further induction of plasticity and little is therefore gained by continued practice of the task. To provide challenges that ensures continued learning, training exercises have to progress from simple movement trajectories to more complex movements, that also incorporates goal setting. Moreover, it has been shown that shaping and variation of tasks in combination with feedback on movement quality is of great importance for the learning outcome. The underlying concept for performing BMCT is, therefore, that improved motor control will optimize the movement strategy, which further leads to improved gait function.

Regarding the effects of BMCT on fatigue, there are diverging results in the literature, but the literature on BMCT for patients with MS is generally of low quality with an inadequate description of interventions, why further studies are warranted.