Massage Therapy Journal Winter 2025

Winter 2025 • 39

(Left) The erector spinae (Right) The extrinsic muscles

mid-back down to the feet is important. Here, a detailed overview of the key muscles involved, including their origins, insertions and actions, is reviewed.

• Trapezius (middle and lower fibers) : Originates from the spinous processes of the thoracic vertebrae and inserts on the spine of the scapula and acromion. Helps with scapular retraction, depression and stabilization, which are crucial for maintaining proper posture. • Quadratus lumborum : Originates from the iliac crest and inserts on the transverse processes of the lumbar vertebrae and the 12th rib. Plays an important role in lateral flexion of the spine and stabilizing the lumbar region. Torso and Core Muscles: • Rectus abdominis : Originates from the pubic symphysis and inserts on the xiphoid process and costal cartilages of ribs 5–7. Flexes the vertebral column and helps maintain posture. • Transverse abdominis : Originates from the lower ribs, thoracolumbar fascia, iliac crest and inguinal ligament and inserts on the linea alba and pubic crest. Compresses the abdomen and provides core stability. • External obliques : Originates from the lower eight ribs and inserts on the iliac crest and linea alba. Assists in rotating and laterally flexing the trunk, as well as compressing the abdominal contents. • Internal obliques : Originates from the thoracolumbar fascia, iliac crest and inguinal ligament and inserts on the lower ribs and

Thoracic Region and Mid-Back Muscles: • Erector spinae group (iliocostalis,

longissimus, spinalis): Originates from the iliac crest, sacrum and lumbar vertebrae and inserts on the ribs, cervical and thoracic vertebrae. This group is responsible for extending the vertebral column and maintaining spinal alignment. • Rhomboids : Originates from the spinous processes of the thoracic vertebrae and inserts on the medial border of the scapula. Responsible for retracting the scapula and helping stabilize the shoulder girdle. • Serratus posterior inferior : Originates from the spinous processes of the lower thoracic and upper lumbar vertebrae and inserts on the lower ribs. Assists in depressing the ribs during exhalation. • Serratus posterior superior : Originates from the spinous processes of C7–T3 and inserts on the upper ribs. Elevates the ribs during inhalation, aiding in respiration. • Serratus anterior : Originates from the lateral aspects of the upper ribs and inserts on the medial border of the scapula. Protracts the scapula and plays a key role in stabilizing the scapulothoracic joint.

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