Stapedius muscle excess movement of the stapes, helping to control the amplitude of sound waves from the general external environment to the inner ear Paralysis of the stapedius allows wider oscillation of the stapes, resulting in heightened reaction of the auditory ossicles to sound vibration. This condition, known as hyperacusis, causes normal sounds to be perceived as very loud. Paralysis of the stapedius muscle may result when the nerve to the stapedius, a branch of the facial nerve, is damaged, or when the facial nerve itself is damaged before the nerve to stapedius branches. In cases of Bell's palsy, a unilateral paralysis
Muscle architecture muscles have broad attachments compared to other muscle types and can shorten to about 40%-60% of their resting length. Strap muscles, such as the laryngeal muscles, have been thought to control the fundamental frequency used in speech production, as well as singing. Another example of this muscle is the longest muscle in the human body, the sartorius. Fusiform muscles are wider and cylindrically shaped in the center and taper off at the ends. This overall shape of fusiform muscles is often referred to as a spindle. The line of action in this muscle type runs in a straight line between