What type of electrical stimulation is described as non-functional?

The term "non-functional" in the context of electrical stimulation typically refers to the kind of stimulation that does not replicate the natural patterns of muscle activity normally elicited by the body. In this case, low frequency muscle twitch stimulation is characterized by its ability to produce muscle contractions through electrical impulses that are not aligned with the body’s natural neuromuscular control. This means that while the muscle may respond and contract, the contractions do not contribute to purposeful movements or functional activities, hence they can be considered "non-functional."

In contrast, direct current and alternating current are types of electrical flow rather than specific modes of stimulating muscles for functional movement. Pulsed current, while it can be used for various therapeutic purposes, is often designed to mimic natural muscle activation patterns, allowing for functional movements. Therefore, these other types of electrical stimulation can involve functional contraction patterns, distinguishing them from low frequency muscle twitch, which focuses more on isolated muscle activity without the utility of functional tasks.