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muscle twitch
muscle twitch A muscle twitch is a brief, involuntary contraction of muscle fibers supplied by a motor unit, often seen as a small twitch or dimpling under the skin.
A muscle twitch is a brief, involuntary contraction of muscle fibers supplied by a motor unit, often seen as a small twitch or dimpling under the skin. It usually is not strong enough to move a limb and may be harmless or linked to motor neuron or peripheral nervous system disease.