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myofascialpain.com
Atlas · Lower Back

Serratus Posterior Inferior

Aching at the thoracolumbar junction aggravated by deep breathing and trunk rotation

Body region
Lower Back
Trigger points
1
documented in this muscle
Common symptoms
3
patterns cataloged
Common causes
4
contributory factors

Trigger points

TrP 1

Serratus Posterior Inferior

Location. Lower back, ribs

Pain referral. Lower back, lower ribs

  • Lower back
  • Lower ribs
  • Upper buttock

Symptoms patients report

Lower back pain. Aching at the thoracolumbar junction aggravated by deep breathing and trunk rotation

Rib discomfort. Pain along the lower rib cage from trigger points in the serratus posterior inferior

Breathing-related pain. Pain during forced expiration as serratus posterior inferior assists in depressing lower ribs

Common causes

Poor posture. Sustained thoracolumbar flexion alters rib cage mechanics increasing serratus posterior inferior load

Shallow breathing. Chronic restricted breathing patterns overwork accessory respiratory muscles including this one

Sitting. Prolonged seated posture compresses lower ribs increasing serratus posterior inferior strain

Weak back muscles. Insufficient paraspinal strength forces accessory muscles to compensate for trunk stability

Treatment & self-care

immediate

Tennis ball against wall on lower ribs and flank area

Stand with your back against a wall and place a tennis ball between the wall and your lower rib/flank area on the painful side. Lean into the ball with comfortable pressure and slowly roll it around the area by shifting your body. When you find a tender spot, hold sustained pressure for 30-60 seconds until the tenderness begins to ease.

Duration
5-10 minutes per session
Frequency
1-2 times per day
Expect
Reduced flank and lower rib tension within several days of consistent use
exercise

Side-lying trunk stretch

Lie on your pain-free side with a pillow under your waist for support. Extend the top arm overhead, reaching toward the wall behind you, to open up the lower rib cage on the affected side. Hold for 20-30 seconds, breathing deeply into the stretch. Repeat 5-8 times.

Duration
5 minutes per session
Frequency
2-3 times per day
Expect
Improved rib cage mobility and reduced breathing-related pain within 1-2 weeks
exercise

Diaphragmatic breathing exercises

Lie on your back with knees bent and one hand on your chest, the other on your belly. Breathe in slowly through your nose, directing the breath into your belly so that hand rises while the chest hand stays relatively still. Exhale slowly through pursed lips for a count of 6-8. Focus on relaxing the lower ribs and flank muscles with each exhale. Perform 10-15 breath cycles.

Duration
5-10 minutes per session
Frequency
3-4 times per day
Expect
Improved breathing mechanics and reduced accessory muscle overuse within 2-3 weeks
exercise

Trunk rotation with resistance band

Anchor a resistance band at waist height. Stand with your side toward the anchor, holding the band with both hands at your center. Slowly rotate your trunk away from the anchor, keeping hips stable. Control the return to center. Perform 12-15 repetitions on each side for 2-3 sets. Progress resistance gradually.

Duration
10 minutes per session
Frequency
3-4 times per week
Expect
Stronger trunk rotational control and reduced strain on serratus posterior inferior within 3-4 weeks
lifestyle

Core strengthening with emphasis on lateral stability

Incorporate side planks, Pallof presses, and suitcase carries into your regular exercise routine. These exercises build lateral core stability that reduces demand on the serratus posterior inferior. Start with modified versions (knees down for side planks) and progress as strength improves.

Duration
15-20 minutes per session
Frequency
3-4 times per week
Expect
Improved lateral trunk stability and reduced vulnerability to flare-ups within 4-6 weeks
professional

Professional assessment to rule out kidney or rib pathology

If flank pain persists beyond 3-4 weeks or is accompanied by changes in urination, fever, or blood in urine, seek professional evaluation promptly. A physician can rule out kidney stones, infections, or rib fractures. Once cleared, a physical therapist can provide targeted myofascial treatment for the serratus posterior inferior.

Duration
Initial evaluation: 30-60 minutes
Frequency
As needed based on symptoms
Expect
Accurate diagnosis distinguishing muscular from visceral pain and appropriate targeted treatment plan
Key Takeaways
  1. Aching at the thoracolumbar junction aggravated by deep breathing and trunk rotation
  2. Pain along the lower rib cage from trigger points in the serratus posterior inferior
  3. Pain during forced expiration as serratus posterior inferior assists in depressing lower ribs