What muscles could cause upper back left side pain?

Muscles that may contribute to upper back left side pain include Ascending part of left trapezius, Descending part of left trapezius, rhomboid major, rhomboid minor, iliocostalis thoracis, longissimus thoracis, Set of left levatores costarum breves. Trigger points, strains, or weakness in these muscles can refer pain to this area.

Upper Back

Upper Back Left Side

Q: What causes pain in the upper back left side?

Common causes of upper back left side pain include muscle strain from one-sided activities, trigger points in the left rhomboid or trapezius, thoracic facet joint irritation, postural imbalance from desk work, rib dysfunction or intercostal strain. The specific cause depends on the nature of the pain, how it started, and which movements aggravate it.

Left-sided upper back pain may stem from the left trapezius, rhomboid, or erector spinae muscles. Asymmetric posture, one-sided activities, or sleeping position can create imbalances that lead to unilateral upper back discomfort.

Medical Disclaimer

This information is for educational purposes only and does not constitute medical advice. Consult a qualified healthcare provider for proper diagnosis and treatment of any pain or medical condition.

Common Causes

Muscle strain from one-sided activities

Trigger points in the left rhomboid or trapezius

Thoracic facet joint irritation

Postural imbalance from desk work

Rib dysfunction or intercostal strain

Muscles in This Area

Upper Back

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.

Trapezius myofascial painCervical strainScapular winging

Upper Back

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.

Trapezius strainScapular dyskinesisMyofascial pain

Upper Back

rhomboid major

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.

Rhomboid strainScapular dyskinesisMyofascial pain syndrome

Upper Back

rhomboid minor

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.

Rhomboid minor strainTrapezius-rhomboid myofascial painPostural syndrome

Upper Back

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.

Thoracic strainPostural myofascial pain

Upper Back

longissimus thoracis

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.

Erector spinae strainThoracolumbar fasciitis

Upper Back

Set of left levatores costarum breves

Short muscles on left side attaching ribs to vertebrae above, elevating ribs during breathing and aiding trunk rotation. Support posture in pulling exercises.

Costovertebral joint sprain

Stretches That May Help

Ear-to-shoulder stretch

Upper trap doorway stretch

Chin tuck with rotation

Scapular depression stretch

One-arm trap pull

Upper back side bend

Doorway scapular stretch

Wall slide

Child's pose with retraction

Scapular wall slide

Pec doorway stretch

Thread the needle

Cat-cow pose

Thoracic extension over foam roller

Child's pose

Cat-cow

Seated spinal twist

Side bend stretch

Thoracic rotation stretch

Recommended Exercises

When to See a Doctor

Seek medical attention if left upper back pain is accompanied by chest pain, shortness of breath, pain radiating to the left arm, or sudden onset without apparent cause, as these may indicate cardiac issues.