Iliocostalis Thoracis Trigger Points

Introduction

The iliocostalis thoracis is a key mid-back muscle responsible for spinal extension, lateral flexion, and posture stabilization. When trigger points develop in this muscle, they can cause mid-back pain, rib tightness, and difficulty breathing, often mimicking rib dysfunction, thoracic spine issues, or intercostal neuralgia.

Name and Area

  • Name: Iliocostalis Thoracis

  • Area: Located in the mid-back, running from the lower ribs to the upper ribs, as part of the erector spinae group.

Indications

Iliocostalis thoracis trigger points may contribute to:

  • Pain in the mid-back and ribs (mistaken for rib dysfunction or intercostal neuralgia)

  • Pain that extends to the shoulder blade or side of the torso (can mimic thoracic spine issues or costochondritis)

  • Stiffness in the mid-back, especially after sitting or sleeping in an awkward position

  • Pain that increases with deep breathing, twisting, or reaching overhead

  • Pain or tightness along the ribs, making it difficult to take deep breaths

  • Fatigue or discomfort in the mid-back with prolonged standing or sitting

Pain from this muscle is often mistaken for thoracic spine dysfunction, rib misalignment, or even lung-related issues.

Muscle Action

  • Extends the Spine: Helps maintain upright posture.

  • Laterally Flexes the Spine: Allows side bending movements.

  • Stabilizes the Ribcage: Supports rib movement during breathing and posture control.

The iliocostalis thoracis is essential for maintaining good posture, ribcage mobility, and core stability.

Signs and Symptoms

Individuals with iliocostalis thoracis trigger points often report:

  • Dull, aching pain in the mid-back that worsens with movement

  • Pain that extends to the side of the ribcage (can mimic rib dysfunction or neuralgia)

  • Tightness in the mid-back that makes twisting or bending difficult

  • Pain that increases after long periods of sitting or poor posture

  • Pain or discomfort when taking deep breaths (feels like a "rib cage restriction")

  • Stiffness or tension that extends to the shoulder blade or lower neck

Pain worsens with prolonged sitting, deep breathing, or sudden twisting movements.

Perpetuating Factors

Common causes of iliocostalis thoracis trigger points include:

  • Prolonged sitting or slouching (leads to chronic back and rib tightness)

  • Poor posture (forward head position, rounded shoulders, or excessive thoracic kyphosis)

  • Repetitive twisting or bending movements (common in golf, tennis, or rotational sports)

  • Heavy lifting without proper core engagement (e.g., carrying heavy objects or lifting with poor form)

  • Chronic shallow breathing (can cause overuse of the iliocostalis thoracis for rib expansion)

Trigger Point Referral Pattern

Trigger points in the iliocostalis thoracis refer pain to:

  • The mid-back and ribcage (Can Mimic Rib Dysfunction or Thoracic Spine Issues)

  • The side of the torso (Mistaken for Intercostal Neuralgia or Costochondritis)

  • The upper back and shoulder blade (Can Resemble Upper Back Strain or Postural Fatigue)

Pain from this muscle is often confused with rib dysfunction, spinal misalignment, or thoracic outlet syndrome.

Differential Diagnosis

Iliocostalis thoracis trigger points may be mistaken for:

  • Rib dysfunction (sharp or aching pain along the ribcage, worsens with deep breathing or movement)

  • Intercostal neuralgia (burning, shooting pain along the rib spaces, can mimic nerve compression)

  • Thoracic spine dysfunction (limited mobility in the upper back, worse with twisting or slouching)

  • Postural strain (tightness and discomfort from poor ergonomics or long hours at a desk)

  • Costochondritis (inflammation of rib cartilage, causes tenderness in the ribcage and chest pain)

A thorough spinal, rib, and respiratory examination is necessary to rule out these conditions.

Associated Trigger Points

Iliocostalis thoracis trigger points often co-exist with:

  • Quadratus lumborum (lower back and rib pain, contributes to postural instability)

  • Latissimus dorsi (side rib and shoulder blade pain, affects overhead movements)

  • Serratus posterior superior (upper rib and shoulder pain, worsens with deep breathing)

  • Trapezius (upper back and neck tension, can cause postural fatigue and shoulder pain)

Anatomy and Innervation

Muscle Origin Insertion Innervation
Iliocostalis Thoracis Lower ribs Upper ribs and transverse processes of cervical vertebrae Dorsal rami of spinal nerves (T1–T12)

The iliocostalis thoracis is innervated by the dorsal rami of thoracic spinal nerves, which also control postural stability and spinal extension.

Patient Examination

A comprehensive examination should include:

  • Palpation: Identify tender nodules along the mid-back and lower ribs.

  • Resisted Back Extension Testing: Assess pain and weakness when extending the spine against resistance.

  • Gait and Posture Analysis: Look for rounded shoulders, excessive thoracic kyphosis, or ribcage tightness.

  • Respiratory Function Testing: Rule out restricted breathing due to rib or spine dysfunction.

Corrective Actions

Dry Needling

  • Dry needling can release trigger points in the iliocostalis thoracis, reducing muscle tightness and improving spinal mobility.

Manual Therapy

  • Trigger Point Release: Apply direct pressure to tight spots in the mid-back and ribcage.

  • Massage Therapy: Helps improve circulation and reduce mid-back muscle tension.

Stretching

  • Side Stretch: Stand and gently lean sideways to stretch the iliocostalis thoracis.

  • Thoracic Extension Stretch: Use a foam roller or chair backrest to improve thoracic spine mobility.

Strengthening Exercises

  • Superman Exercise: Strengthens the erector spinae and improves spinal posture.

  • Bird-Dog Exercise: Improves core activation and reduces strain on the mid-back.

  • Thoracic Rotation Drills: Helps improve spinal mobility and reduce stiffness.

Postural and Movement Adjustments

  • Avoid prolonged sitting without back support (take standing breaks every 30–60 minutes).

  • Use proper ergonomics at work (maintain a neutral spine to reduce mid-back strain).

  • Incorporate deep breathing exercises (encourages proper rib expansion and thoracic mobility).

Conclusion

The iliocostalis thoracis plays a crucial role in spinal extension, rib mobility, and postural stability, but trigger points in this muscle can cause significant mid-back, rib, and shoulder pain. By incorporating dry needling, manual therapy, stretching, and strengthening exercises, individuals can reduce pain, improve mobility, and prevent future dysfunction.

➡️ Learn more about Trigger Points

Sources:

  • Travell, J. G., & Simons, D. G. (1983). Myofascial Pain and Dysfunction: The Trigger Point Manual (2nd ed.). Williams & Wilkins.

  • Simons, D., & Travell, J. (1999). The Trigger Point Manual, Volume 2: The Lower Extremities. Williams & Wilkins.