Erector Spinae

The erector spinae is a group of three deep muscles that run vertically along each side of the spine, playing a key role in posture and spinal movement.

This muscle group consists of the iliocostalis, longissimus, and spinalis muscles, which work together to extend, laterally flex, and stabilize the spine.

The erector spinae is essential for everyday movements such as standing upright, bending backward, and lifting, making it a crucial component in both functional movement and injury prevention.

Erector Spinae
Erector Spinae

Erector
Spinae

Anatomy

[Origin]

  • A broad tendon from posterior part of iliac crest
  • Posterior surface of sacrum
  • SI ligaments
  • Aacral and inferior lumbar spinous processes
  • Supraspinous ligament

[Insertion]

  • Iliocostalis: lumborum, thoracis, cervicis; fibers run superiorly to angles of lower ribs and cervical transverse processes
  • Longissimus: thoracis, cervicis, capitis; fibers run superiorly to ribs between tubercles and angles to transverse processes in thoracic and cervical regions, and to mastoid process of temporal bone
  • Spinalis; thoracis, cervicis, capitis; fibers run superiorly to spinous processes in the upper thoracic region and to cranium

    [Action]

    • Acting bilaterally: extend vertebral column and head; as back is flexed, control movement via eccentric contraction
    • Acting unilaterally: laterally flex vertebral column

    Clinical Relevance

    Erector Spinae Flexion-Relaxation Phenomenon

    The flexion-relaxation phenomenon is defined as silencing of the erector spinae myoelectric activity during full trunk flexion. In healthy individuals with no low back pain, the erector spinae muscles relax in a range from upright position to full- lumbar flexion, due to the deep back muscles (multifidus) acting to stabilize the lumbar spine.

    In individuals with low back pain, the erector spinae flexion-relaxation phenomenon is absent. As the erector spinae functions to stabilize the lumbar spine due to laxity of the passive structures and changes in the neuromuscular activation pattern.

     

    ~ Evidence-Based Exercises ~

    According to an EMG study, the exercises that demonstrated significant muscle contractions of Erector Spinae are;

    • Back Extension
    • Front Plank
    • Deadlift

    Back Extension

    Back Extension

    Front Plank

    Front Plank

    Deadlift

    Deadlift

    < Reference >

    • Keith L. Moore, Anne M. R. Agur, Arthur F. Dalley. Moore Clinically Oriented Anatomy 7th Edition, Lippincott Williams & Wilkins, 2013
    • Maeo S., Takahashi T., Takai Y., Kanehisa H. Trunk muscle activities during abdominal bracing: Comparison among muscles and exercises.  Sports Sci. Med. 2013;12:467–474
    • Park S., Yoo W., An D., Oh J., Lee J., Choi B. Comparison of isometric exercises for activating latissimus dorsi against the upper body weight.  Electromyogr. Kinesiol. 2015;25:47–52
    • Van Den Tillaar R., Saeterbakken A.H. Comparison of core muscle activation between a prone bridge and 6-RM back squats.  Hum. Kinet. 2018;62:43–53
    • Andersen V., Fimland M.S., Mo D.A., Iversen V.M., Vederhus T., Rockland Hellebø L.R., Nordaune K.I., Saeterbakken A.H. Electromyographic comparison of barbell deadlift, hex bar deadlift, and hip thrust exercises: A cross-over study.  Strength Cond. Res. 2018;32:587–593