What is the smallest skeletal muscle in the human body?

The stapedius is generally regarded as the smallest skeletal muscle in the human body.

It is located in the middle ear and attaches to the stapes, the smallest bone. When the stapedius contracts, it pulls on the stapes and reduces the extent of its movement. This action forms part of the acoustic reflex, which helps protect the inner ear from some loud sounds and reduces the effect of self-generated sounds such as speaking.

The stapedius is supplied by a branch of the facial nerve. Damage to that nerve can paralyze the muscle and contribute to hyperacusis, a condition in which ordinary sounds seem unusually loud or uncomfortable.

The stapedius should not be confused with the tensor tympani, another tiny middle-ear muscle. The tensor tympani attaches to the malleus and is supplied by a branch of the trigeminal nerve. Both muscles influence sound transmission, but they act on different ossicles.