(61) During this procedure, the branches of the recurrent laryngeal nerve innervating the thyroarytenoid (TA) and lateral cricoarytenoid
(LCA) muscles are transected.
The effective medial excursion magnitude of vocal fold produced by the three adductors physiologically is sequentially as following: Rotation effect by lateral cricoarytenoid
(LCA), mass or volume effect by thyroarytenoid (TA) and then shift effect by interarytenoid (IA) muscle.
* Bilateral transarytenoid and lateral cricoarytenoid
myectomy--This surgery is usually performed one side at a time, at least six months apart.
In addition, botulinum toxin injection into the lateral cricoarytenoid
muscle is helpful in some patients.
The muscular process is the insertion point of the posterior and lateral cricoarytenoid
There are four pairs of muscle groups in the larynx: the thyroarytenoid, the lateral cricoarytenoid
, the posterior cricoarytenoid, and the cricothyroid muscles.
High CQ requires increased glottal adduction, which might correspond to stronger contraction of the interarytenoid and lateral cricoarytenoid
muscles, as well as increased medial compression from activity in the thyroarytenoids.
Laryngeal EMG evaluates neuromuscular activity and integrity of the laryngeal muscle adductors (thyroarytenoid and lateral cricoarytenoid
) and abductors (posterior cricoarytenoid).
Likewise, lateral cricoarytenoid
(LCA) and interarytenoid (IA) muscle contraction produces more adduction, but primarily on the upper part of the vocal fold, at the vocal processes.
Botulinum toxin was injected into the right lateral cricoarytenoid
 The third motor branch innervates the lateral cricoarytenoid
muscle (LCA), passing through it to terminate in the thyroarytenoid muscle (TA).
 This is in contrast to other evidence that suggests that fast-twitch fibers in the thyroarytenoid and lateral cricoarytenoid
muscles are reinnervated more rapidly and to a greater degree than slow-twitch fibers.