Fatiga muscular

Muscle fatigue is a problem still poorly understood, when not forgotten. Its generic representation is clinically little or not operative, and even more so if it has to be related to the workload, which in its heterogeneity is presented as a chimera, as a "ghost" (Sperantio, 1972). Fatigue, both local and general, is a factor that must be kept in mind in the context of professional risks. It also affects organs that do not appear to have been active (such as the brain, with disorders that decrease the ability to work), being explained by the catabolic substances formed that are discharged into the bloodstream, causing phenomena of general intoxication (Nóvoa Santos, 1948) . Muscle fatigue can be registered with EMGS (surface electromyography). The bioelectric result can be systematized into two main groups: (1) representation of the signal as a function of the voltage / time relationship that is transmitted to the amplitude of the signal; (2) representation of the signal as a function of frequencies. Such parameters make it possible to differentiate contractile fatigue (expressed in amplitude) from metabolic fatigue (registered in the frequency domain), which is even more interesting considering that metabolic fatigue precedes contractile fatigue, and that muscular fatigue does not it arises abruptly but is "a process through time" (Basmajian JV, De Luca CJ. Muscle Alive, 1985). The EMGS, together with other exploratory tests, has to contribute to provide useful data to the therapist in the patient's evolutionary course, being able to agree on their practice before treatment (verify the deficiencies) during (appreciate the evolution) and afterwards (check the results). It can also provide support to identify groups at risk for the development of musculoskeletal disorders in the future, such as low back pain, especially when they are people under a considerable workload. The foregoing, extensively, should be transferred to other areas, such as increasing sports performance and preventing injuries.