Low and medium Frequency Electrotherapy - Implox
Low and medium Frequency Electrotherapy - Implox
Low and medium Frequency Electrotherapy - Implox
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For practically all skeletal muscles, tetanic contraction requires a minimum frequency of 7 Hz. <strong>Low</strong>er frequencies<br />
result in separate contractions (2) (Fig. 31). The most comfortable tetanic contractions are obtained with frequencies<br />
between 40 <strong>and</strong> 80 Hz.<br />
N.B. In view of the frequency, faradic current is not only suitable for muscle stimulation but, with a lower amplitude<br />
(sensitivity threshold), also gives good results in pain suppression (see paragraph 2.3.3 Wyss).<br />
4.4.2 Application of faradic current<br />
It will be clear that muscle stimulation with faradic current the muscle must have a good general innervation. The<br />
current may be applied for both diagnostic <strong>and</strong> therapeutic objectives.<br />
Fig. 31.<br />
Production of an isometric tetanic contraction by increasing the stimulation frequency.<br />
Diagnostic objectives include:<br />
• investigation of myasthenic reaction;<br />
• investigation of myotonic reaction;<br />
• localization of a neurapraxia block.<br />
In therapy, faradic current is still frequently applied in the form of FES (Functional Electro-Stimulation). In this<br />
technique, the application of the electrical stimulus is combined with activity on the part of the patient. FES may be<br />
applied in the following cases:<br />
• post-operative or post-traumatic inability to achieve voluntary contraction of certain muscles;<br />
• early stages of re-innervation;<br />
• atrophy following long-duration immobilization;<br />
• paralysis/paresia (e.g. as a consequence of hemiplegia). In walking difficulties, stimulation can be applied via a<br />
peroneus stimulator.<br />
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