GENERAL INFORMATION
The cricoarytenoid muscles are a group of muscles within the larynx that control vocal cord movement. There are two critical muscles within this group: the posterior cricoarytenoid and the lateral cricoarytenoid. These muscles are essential for regulating airflow through the vocal cords and are involved in both speech production and breathing. Their primary function is to open and close the glottis (the space between the vocal cords), enabling sound-controlled output and facilitating respiration.
ORIGIN
- Posterior Cricoarytenoid: Originates from the posterior surface of the cricoid cartilage.
- Lateral Cricoarytenoid: Originates from the upper border of the cricoid cartilage.
INSERTION POINT
- Posterior Cricoarytenoid: Inserts into the muscular process of the arytenoid cartilage.
- Lateral Cricoarytenoid: Inserts into the muscular process of the arytenoid cartilage as well.
MAJOR ARTERIES
- Superior Laryngeal Artery: This artery supplies blood to the cricoarytenoid muscles, ensuring they receive adequate oxygen and nutrients.
- Inferior Laryngeal Artery: Also contributes to the blood supply of the laryngeal muscles, supporting cricoarytenoid function.
NEURAL INNERVATION
- Recurrent Laryngeal Nerve: A branch of the vagus nerve that innervates both the posterior and lateral cricoarytenoid muscles, providing motor control essential for vocal cord movement.
TRIGGER POINT
- Overuse or strain of the cricoarytenoid muscles can lead to tightness or discomfort in the throat. This strain may manifest as difficulty in speaking, breathing issues, or hoarseness. Tenderness can be felt in the laryngeal area, particularly after prolonged voice use.
CONCENTRIC FUNCTION
- Posterior Cricoarytenoid: In concentric contraction, this muscle abducts the vocal cords, pulling them apart to open the airway for breathing.
- Lateral Cricoarytenoid: Contracts to adduct the vocal cords, bringing them together to close the glottis for sound production during speech or singing.
ECCENTRIC FUNCTION
- Posterior Cricoarytenoid: During an eccentric contraction, the muscle lengthens, allowing controlled closure of the vocal cords after inhalation.
- Lateral Cricoarytenoid: Eccentrically, this muscle releases tension to open the vocal cords slowly, aiding in smooth transitions during speech or between breathing and talking.
ISOMETRIC FUNCTION
- Both cricoarytenoid muscles can hold the vocal cords in a steady position during sustained phonation, such as keeping a note or speaking continuously without changing pitch. It is vital for maintaining stable voice control.
RELATED MUSCLES – SCIENTIFIC NAMES
- Thyroarytenoid Muscle: Helps with vocal cord tension and relaxation.
- Cricothyroid Muscle: Lengthens and tightens the vocal cords for higher-pitched sounds.
- Vocalis Muscle: Works alongside the thyroarytenoid to fine-tune vocal cord tension.
- Interarytenoid Muscle: Assists with vocal cord adduction, closing the glottis during speech.
ANTAGONIST
- Posterior Cricoarytenoid: Acts as the antagonist to the lateral cricoarytenoid muscle by abducting the vocal cords.
- Lateral Cricoarytenoid: Opposes the posterior cricoarytenoid by adducting the vocal cords, closing the airway for phonation.
COMMON INJURIES
- Cricoarytenoid Arthritis: Inflammation of the cricoarytenoid joint can cause hoarseness and difficulty breathing. It is often associated with autoimmune diseases.
- Vocal Cord Paralysis: Damage to the recurrent laryngeal nerve can impair cricoarytenoid function, leading to a weakened or breathy voice and difficulty controlling pitch.
- Vocal Cord Strain: Overuse of the cricoarytenoid muscles can result in voice fatigue, hoarseness, or pain, particularly after extended periods of speaking or singing.
- Laryngitis: Inflammation of the laryngeal muscles, including the cricoarytenoid muscles, can lead to temporary voice loss or voice strain.
- Posterior Cricoarytenoid Muscle Dysfunction: Results in difficulty with breathing due to impaired vocal cord abduction.
EXERCISES
- Deep Breathing Exercise: Inhale deeply, then exhale slowly while humming. This exercise strengthens the posterior cricoarytenoid by engaging the muscles responsible for opening the vocal cords.
- Lip Trills: Exhale air through your lips while producing a sound. This exercise works both cricoarytenoid muscles by promoting smooth adduction and abduction of the vocal cords.
- Pitch Glides: Move from low to high pitches and back again. This exercise helps the lateral cricoarytenoid by fine-tuning vocal cord tension for better pitch control.
- Sustained Vowel Sounds: Hold a vowel sound at varying pitches to engage the cricoarytenoid muscles, improving vocal endurance and control.
- Falsetto Practice: Sing in a falsetto voice to activate the cricoarytenoid muscles at higher pitches, helping to improve flexibility and strength in vocal cord movements.
STRETCHES
- Neck Side Stretch: Slowly tilt your head to one side, holding for 20-30 seconds. This stretch helps release tension in the neck muscles, easing the strain on the cricoarytenoid muscles.
- Neck Rotation: Gently rotate your head in a circular motion to loosen the muscles surrounding the larynx, helping to reduce any tension affecting vocal control.
- Jaw Stretch: Open your mouth as wide as possible and hold for a few seconds to stretch the jaw and surrounding muscles, alleviating strain on the vocal cords.
- Tongue Stretch: Stick your tongue out and hold for 10 seconds. This stretch reduces tension in the base of the tongue, indirectly helping the cricoarytenoid muscles function better.
- Shoulder Shrugs: Slowly raise and lower your shoulders to relieve upper body tension that can affect the neck and larynx. This stretch promotes relaxation in the muscles supporting the vocal cords.