ABSTRACT
Background: Multiple sclerosis (MS) is a progressive and neurodegenerative disease of the central nervous system. Its symptoms vary greatly, which makes its diagnosis complex, expensive, and time-consuming. One of its most prevalent symptoms is muscle fatigue. It occurs in about 92% of patients with MS (PwMS) and is defined as a decrease in maximal strength or energy production in response to contractile activity. This article aims to compare the behavior of a healthy control (HC) with that of a patient with MS before and after muscle fatigue. Methods: For this purpose, a static baropodometric test and a dynamic electromyographic analysis are performed to calculate the area of the stabilometric ellipse, the remitting MS (RMS) value, and the sample entropy (SampEn) of the signals, as a proof of concept to explore the feasibility of this test in the muscle fatigue quantitative analysis; in addition, the statistical analysis was realized to verify the results. Results: According to the results, the ellipse area increased in the presence of muscle fatigue, indicating a decrease in postural stability. Likewise, the RMS value increased in the MS patient and decreased in the HC subject and the opposite behavior in the SampEn was observed in the presence of muscle fatigue. Conclusion: Thus, this study demonstrates that SampEn is a viable parameter to estimate muscle fatigue in PwMS and other neuromuscular diseases.
ABSTRACT
BACKGROUND: Mechanical behavior is difficult to monitor in experimental environments, usually because of geometric or technology implementation limitations. Nevertheless, thermography has been shown to overcome these issues. OBJECTIVES: The aim of this study was to evaluate four types of assemblies between a Jaipur foot and a polyethylene tube using infrared thermography in order to find the best mechanical configuration in terms of thermal behavior. STUDY DESIGN: Mechanical testing. TECHNIQUE: An infrared camera captured short videos every 5 min over 10 h in six different positions (three in the back and three in front of the Jaipur foot) around a prosthesis subjected to repetitive stresses (axial force 980 N) simulating kinematic variables like joint angles. We established a region of interest around the foot-ankle assemblies and calculated maximum temperatures and thermographic indices. RESULTS: In this study, the best foot-ankle assembly used epoxy adhesive because it presented the lowest temperature in the six positions and the lowest thermal index. CONCLUSIONS: Thermographic techniques can be used to study mechanical behaviors in complex experimental situations.
