Muscles/Upper Back

Upper Back

longissimus thoracis

lon-JIS-ih-mus tho-RAH-siss

The longest erector spinae muscle, running parallel to the spine from sacrum to mid-back, it extends the spine and maintains upright posture. Essential for deadlifts, squats, and spinal stability in powerlifting. Weakness leads to back rounding under load.

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Common Pain & Injury

Strains from heavy lifting cause thoracolumbar pain and stiffness. Pain may radiate to hips. See doc for bowel/bladder changes or leg weakness.

Anatomy & Function

Origin

Thoracolumbar fascia and sacrum (lower back connective tissue)

Insertion

T4-L5 transverse processes (mid to lower thoracic and lumbar ribs)

Actions

Extends thoracolumbar spine (back arch)
Laterally flexes trunk

Innervation

Dorsal rami of spinal nerves

Muscle Relationships

Antagonists

Rectus abdominis

Synergists

Iliocostalis lumborumSpinalis thoracis

Trigger Points

Along paraspinals; refers locally or to abdomen/hips.

Stretches

1Child's pose

2Cat-cow

3Seated spinal twist

Common Conditions

Erector spinae strainThoracolumbar fasciitis

Anatomical Parts

Left longissimus thoracisRight longissimus thoracis

FAQ

What is longissimus thoracis?

Erector spinae muscle that extends the mid-back.

Longissimus thoracis pain causes?

Overload from lifting leads to thoracolumbar ache.

Strengthen longissimus thoracis?

Deadlifts and back extensions build it.

Lower back erector pain?

Tight longissimus from poor form refers locally.

Also Works longissimus thoracis

10

Alternating Hang Clean position 1

Alternating Hang Clean position 2

Alternating Hang Clean

intermediate·kettlebells

Anti-Gravity Press position 1

Anti-Gravity Press position 2

Anti-Gravity Press

beginner·barbell

Back Flyes - With Bands position 1

Back Flyes - With Bands position 2

Back Flyes - With Bands

beginner·bands

Backward Drag position 1

Backward Drag position 2

Backward Drag

beginner·other

Band Assisted Pull-Up position 1

Band Assisted Pull-Up position 2

Band Assisted Pull-Up

beginner·other

Band Good Morning position 1

Band Good Morning position 2

Band Good Morning

beginner·bands

Band Good Morning (Pull Through) position 1

Band Good Morning (Pull Through) position 2

Band Good Morning (Pull Through)

beginner·bands

Band Pull Apart position 1

Band Pull Apart position 2

Band Pull Apart

beginner·bands

Barbell Ab Rollout position 1

Barbell Ab Rollout position 2

Barbell Ab Rollout

intermediate·barbell

Barbell Ab Rollout - On Knees position 1

Barbell Ab Rollout - On Knees position 2

Barbell Ab Rollout - On Knees

expert·barbell

Related Upper Back Muscles

Ascending part of left trapezius

Upper fibers of left trapezius elevate and retract scapula for shrugs and pulls. Key for posture and overhead strength. Left-side focus corrects imbalances.

Descending part of left trapezius

The descending part of the left trapezius fibers run downward from neck to scapula on the left side, aiding scapular depression and upward rotation. Key for pull-ups and lat work, preventing shoulder hike.

Descending part of right trapezius

The descending part of the right trapezius fibers slope from occiput to right scapula, depressing and upwardly rotating the scapula. Essential for balanced shoulder mechanics in bilateral lifts.

iliocostalis thoracis

Iliocostalis thoracis, mid erector spinae, runs parallel to spine from low-mid back to upper ribs, aiding thoracic extension and breathing. Supports rows, pulls, and posture in upper body training.

interspinalis thoracis

Tiny interspinalis thoracis muscles between thoracic spinous processes fine-tune extension.

The rhomboid major is a diamond-shaped muscle between your shoulder blades, retracting the scapula for better posture. It stabilizes during rows, pull-ups, and presses, countering slouched shoulders in gym-goers. Weak rhomboids lead to rounded posture and shoulder issues.

The rhomboid minor, above the major, connects upper thoracic spine to the shoulder blade's inner border. It retracts and stabilizes the scapula during upper body pulls. Essential for posture correction in lifters with desk jobs.

semispinalis thoracis

Semispinalis thoracis is a deep erector spinae muscle from thoracic spine, extending the vertebral column. Maintains thoracic posture during deadlifts and rows. Prevents slouching in prolonged sitting.

Upper Back Pain Guide

Common causes and relief

Activities & Sports

See which activities use longissimus thoracis