GENERAL INFORMATION
The Anterior Scalene muscle, one of three scalene muscles, is situated deep within the lateral neck. It plays a pivotal role in respiratory mechanics and cervical spine mobility. This muscle spans from the cervical vertebrae to the first rib, facilitating breathing and aiding in lateral neck flexion and rotation. As a key component of the neck’s muscular network, the Anterior Scalene is involved in several biomechanical functions that support daily activities like turning the head or taking deep breaths. Its strategic location also makes it susceptible to tension, which can impact overall neck health and function.
ORIGIN
The Anterior Scalene originates from the anterior tubercles of the transverse processes of the third to sixth cervical vertebrae (C3-C6). Consequently, this origin provides the leverage necessary for its action on the cervical spine and rib cage.
INSERTION POINT
This muscle inserts onto the scalene tubercle of the first rib, and its fibres may extend to the upper surface of the rib near the subclavian groove. This insertion point is crucial for its role in elevating the first rib during respiration.
MAJOR ARTERIES
The muscle is primarily supplied by the ascending cervical artery, a branch of the thyrocervical trunk, ensuring it receives adequate blood flow to sustain its functions.
NEURAL INNERVATION
The Anterior Scalene is innervated by branches from the cervical spinal nerves (C4-C6). This innervation pattern allows for precise control over its complex actions.
TRIGGER POINT
Trigger points in the Anterior Scalene can lead to neck pain, discomfort radiating to the chest and shoulders, and symptoms that mimic thoracic outlet syndrome due to its proximity to the brachial plexus and vascular structures.
CONCENTRIC FUNCTION
Concentric contraction of the Anterior Scalene results in elevation of the first rib, aiding in inhalation, and assists in lateral flexion of the neck to the same side.
ECCENTRIC FUNCTION
Eccentrically, it helps control the lowering of the first rib during exhalation and stabilizes the neck during opposite-side rotation and extension movements.
ISOMETRIC FUNCTION
Isometrically, the Anterior Scalene stabilizes the cervical vertebrae and the first rib, maintaining posture and ensuring efficient respiratory mechanics.
RELATED MUSCLE-SCIENTIFIC NAMES
- Middle Scalene
- Posterior Scalene
- Sternocleidomastoid
ANTAGONIST
- Sternocleidomastoid (when rotating head to the opposite side)
- Middle and posterior scalenes (during specific movements)
- Trapezius
COMMON INJURIES
- Muscle Strain: Often due to overuse or poor posture, leading to pain and restricted movement.
- Thoracic Outlet Syndrome: Compression at the thoracic outlet affects nerves and blood vessels, causing pain and numbness in the arms.
EXERCISES
- Neck Side Bends: Gently tilt the head towards each shoulder to engage and strengthen the Anterior Scalene.
- Elevated Arm Breathing: Raise one arm, inhale deeply to expand the chest and engage the scalenes.
- Supine First Rib Mobilization: While lying down, perform gentle neck stretches combined with deep breathing to mobilize the first rib.
- Scalene Stretch With Arm Support: Use a chair to support the arm and lean away to stretch the scalene muscles.
- Isometric Neck Contractions: Press the head against a fixed object without moving to strengthen the neck muscles.
STRETCHES
- Scalene Stretch: Gently pull the head toward one shoulder while looking upward to stretch the Anterior Scalene.
- Cross-Body Neck Stretch: Pull the neck diagonally across the body to target different fibres of the scalene muscles.
- First Rib Release: Use a foam roller or therapist’s assistance to gently mobilize the first rib and alleviate tension.
- Overhead Arm Stretch: Raise an arm overhead and lean to the opposite side to deeply stretch the neck and upper thoracic area.
- Yoga Poses For Neck Flexibility: Engage in poses like ‘Cow Face’ that naturally stretch the lateral neck muscles and improve flexibility.