small local contractions of muscles which can be seen visibly through the skin.

Spontaneous contractions of all the muscle fibers in a motor unit (a fascicle of muscle fibers), which occur in early stages of muscle denervation. They presumably reflect abnormal activity of the motoneuron. Fasciculations can be seen during physical examination if the affected muscle is close to the body surface. They appear as subtle ripples or waves of contraction that pass across the skin surface.

involuntary muscle contractions / twitches.

Involuntary contractions, or twitching of groups of muscle fibers, a courser form of muscle contractions than fibrillation.

Visible involuntary contraction or twitching of muscle fibers which are innervated by a single motor unit. Most arise from the distal axon. When accompanied by wasting and weakness, they can signify lower motor neuron disease. They may be commonly found in normal subjects.

Fine tremors of muscles.

Muscle twitching seen with peripheral motor nerve injury.

Frequent small, localized muscle contractions.

Non-painful, rapid and involuntary contractions or twitchings of groups of muscle fibers.

Involuntary contractions or twitching of muscle fibers, visible under the skin.