A tetanic contraction occurs when a motor unit has been maximally stimulated by its motor neuron. It often occurs during tetanic stimulation of the motor unit, usually muscle or nerve. They may also occur as part of an extrapyramidaladverse drug reaction of some typical antipsychotic drugs, specifically the opisthotonos effect of acute dystonic reaction in which "tetanic" heightening of entire body, head and belly up occurs.
