Intramuscular hemangioma in the anterior scalene muscle
diagnosed by core needle biopsy.
Upon exiting their respective neural foramina, the roots travel in the interscalene space, bounded anteriorly by the anterior scalene muscle
, posteriorly by the middle/posterior scalene muscles, and inferiorly by the subclavian artery/first rib.
The first site is the interscalene triangle, where compression can occur between the anterior scalene muscle
, middle scalene muscle and the medial surface of the first rib inferiorly.
Christo used a CT scanner to guide the placement of the needle in the patient's anterior scalene muscle
in the neck.
Anterior scalene muscle arises from the anterior tubercles of the transverse processes of third or fourth to the sixth cervical vertebrae (Hollinshead, 1968).
In 15% of cases, C5 and C6 roots may fuse before piercing the anterior scalene muscle or C5 root alone can pierce the belly of anterior scalene muscle, as seen in 13% of cases.
Myoelectric manifestations of sternocleidomastoid and anterior scalene muscle
fatigue in chronic neck pain patients.
A cervical rib may cause symptoms by narrowing the space between the posterior aspect of the first rib and anterior scalene muscle
through which the nerves and subclavian artery pass to enter the axilla.
Two of the most important musculoskeletal considerations in TOS are the amount of space between the rib and clavicle, the costoclavicular space and interscalene triangle (the space bounded by the anterior scalene muscle
anteriorly), the middle scalene posteriorly, and the first rib inferiorly.
The subclavian artery travels through the interscalene triangle with the plexus, while the subclavian vein courses anteriorly to the anterior scalene muscle
The results revealed increased electromyographic amplitude of the large superficial sternocleidomastoid, and anterior scalene muscles
in patients with neck pain.
2,4,6,10,11) Compression of the vein in the thoracic outlet through lateral abduction of the arm or hypertrophy of subclavian or anterior scalene muscles
can cause turbulence in the vein, which is exacerbated by increased venous flow experienced during exercise.