Assessment of Muscle Fatigue, Strength and Muscle Activation During Exercises with the Usage of Robot Luna EMG, Among Patients with Multiple Sclerosis

Abstract

Objective measurement of fatigability in patients with neurological diseases remains a problem rarely described in the research. The quick and easy assessment of muscle fatigue among patients with multiple sclerosis (MS) is a needed tool, which could be implemented as a standard test among those patients, to better plan and conduct physiotherapy. New devices, such as Luna EMG, allows to create precise environment, to carry out objective assessment and providing data based on strength and electromyography (EMG) measurement, especially median frequency (MDF), which is the standard parameter to indicate fatigue. The experiment was performed among 25 MS patients. Subjects were asked to perform 5 min isokinetic exercise of elbow flexion and extension and 2 min of isokinetic exercise of the same joint, with a 2 min break between. RMS value, median of frequency and its slope during exercise, was assessed for biceps and triceps brachii. The mean strength of both muscles were measured at the same time, accompanied by the automated counting of repetition. The correlation concerning triceps brachii has been found, between the amount of repetition in first exercise, with the slope of frequency in the first exercise (5 min isokinetic exercise). The same correlation for triceps brachii has been found for the second isokinetic exercise (2 min isokinetic exercise). For biceps brachii different correlation has occurred. The correlation between amount of repetition in 5 min isokinetic exercise and the slope in second (2 min) exercise has been noted. The mean strength during flexion for 5 min exercise was 11.20 Nm and 9.5 for extension. During 2 min exercise the mean values were 11.53 Nm and 10.18 Nm respectively. Assessment of MS patients performed with the usage of newest devices allows us to observe muscle fatigue, strength, muscle activation and relations between them among patients with MS. This quick test, accompanied by functional assessment can be a base for patient objective evaluation and a good foundation for planning and controlling training, in terms of muscle fatigue, applied force, muscle activation and coordination.