GENERAL INFORMATION
The cricoarytenoid lateral are small but critical muscles located within the larynx. They play a significant role in vocal cord movement by adducting (closing) the vocal cords, which is essential for phonation and controlling airflow during speech. These muscles work in tandem with other laryngeal muscles to regulate sound production, protect the airway, and allow precise vocal control, particularly during speech and singing.
ORIGIN
This muscle originate from the upper border of the cricoid cartilage, a ring-shaped cartilage structure located in the lower part of the larynx.
INSERTION POINT
These muscles insert into the muscular process of the arytenoid cartilage, allowing them to control the position of the vocal cords effectively.
MAJOR ARTERIES
- Superior Laryngeal Artery: Supplies blood to the lateral cricoarytenoid muscles, ensuring adequate nourishment as well as oxygenation.
- Inferior Laryngeal Artery: Provides additional blood flow to the lower laryngeal structures, including the cricoarytenoid lateral muscles.
NEURAL INNERVATION
- Recurrent Laryngeal Nerve: A branch of the vagus nerve that innervates the cricoarytenoid lateral, providing motor control essential for adducting the vocal cords during speech.
TRIGGER POINT
Tension in the cricoarytenoid lateral can result in vocal strain, difficulty controlling pitch, or hoarseness. Overuse of the voice or poor vocal technique may lead to discomfort in the laryngeal area.
CONCENTRIC FUNCTION
In concentric contraction, the cricoarytenoid lateral muscles shorten, pulling the vocal cords together (adduction). This action closes the glottis, allowing for sound production during phonation.
ECCENTRIC FUNCTION
During an eccentric contraction, the cricoarytenoid lateral lengthen, allowing the vocal cords to gradually open. This function helps modulate sound volume and ease the transition between speech and breathing.
ISOMETRIC FUNCTION
The cricoarytenoid lateral can maintain tension without changing length, holding the vocal cords in a closed position to sustain a consistent tone or pitch during prolonged vocalisation.
RELATED MUSCLES – SCIENTIFIC NAMES
- Posterior Cricoarytenoid Muscle: Works to abduct the vocal cords, opening the airway for breathing.
- Thyroarytenoid Muscle: Contributes to vocal cord tension, assisting in pitch control.
- Cricothyroid Muscle: Lengthens the vocal cords, raising the pitch.
- Vocalis Muscle: Fine-tunes vocal cord tension for precise sound modulation.
ANTAGONIST
- Posterior Cricoarytenoid Muscle: Acts as the antagonist to the cricoarytenoid lateral by abducting (opening) the vocal cords to allow airflow during breathing.
COMMON INJURIES
- Vocal Cord Strain: Overuse of the cricoarytenoid lateral muscles, particularly in singers or speakers, can lead to hoarseness and vocal fatigue.
- Laryngitis: Inflammation of the laryngeal muscles, including the cricoarytenoid lateral muscles, can cause voice loss or significant vocal strain.
- Cricoarytenoid Joint Dysfunction: Injury to the joint can limit the movement of the lateral cricoarytenoid muscles, leading to impaired vocal cord closure and reduced vocal control.
- Muscle Fatigue: Prolonged use of the voice can fatigue the cricoarytenoid lateral muscles, resulting in a strained or breathy voice.
- Vocal Cord Nodules: Repeated stress on the vocal cords can cause the development of nodules, which impact the function of the cricoarytenoid lateral and result in a rough or strained voice.
EXERCISES
- Humming Exercise: Hum softly at different pitches to engage the cricoarytenoid lateral muscles. This exercise promotes relaxation while improving vocal control.
- Pitch Range Drills: Sing through your entire pitch range, focusing on smooth transitions between low and high notes. This exercise strengthens the lateral cricoarytenoid muscles, enhancing vocal flexibility.
- Lip Trills: Exhale through your lips while producing sound. This exercise helps activate the cricoarytenoid lateral by encouraging controlled vocal cord adduction.
- Sustained Vowel Sounds: Hold vowel sounds at varying pitches. This exercise strengthens the cricoarytenoid lateral muscles by promoting consistency in vocal cord closure.
- Vocal Sirens: Slide through various pitches in a siren-like sound, stretching and strengthening the lateral cricoarytenoid muscles for improved voice modulation.
STRETCHES
- Neck Side Stretch: Slowly tilt your head to one side and hold for 20-30 seconds. This stretch releases tension in the neck and laryngeal area, helping relax the cricoarytenoid lateral.
- Neck Rotations: Gently rotate your head in a circular motion to loosen the muscles around the larynx. This stretch helps ease tension in the lateral cricoarytenoid, improving flexibility.
- Jaw Stretch: Open your mouth as wide as possible and hold for a few seconds to stretch the jaw and surrounding muscles, reducing strain on the vocal cords.
- Tongue Extension: Extend your tongue out as far as possible and hold for 10 seconds. This stretch reduces tension in the base of the tongue, indirectly benefiting the cricoarytenoid lateral muscles.
- Shoulder Shrugs: Slowly raise and lower your shoulders to release upper body tension that can affect the muscles of the larynx, including the cricoarytenoid lateral.