​Anatomy of pectoralis minor
Picture

​Pectoralis minor is a small & deep muscle. Spasm mechanism of this muscle will limit the ability of the rib cage to expand, resulting in Shortness of Breath.
 
In BENPHYSIO, we believe that when pectoralis minor is involved, we will look into the short head biceps (SHBiceps) and levator scapulae as well (coupling muscles group). This is because the SHBiceps is attached to coracoid process of scapula. Both muscles’ contraction can caused scapula protraction. Besides that, we will look into levator scapulae as this muscle responsible for scapula upward rotation. We believe that rounded shoulders not only involving scapula protraction but also scapula upward rotation due to the coupling muscles.

Origin: Front 3rd to 5th ribs, close to costal cartilage (Variations in the origin of this muscle in common) 
Insertion: Superior - Medial border of coracoid process of scapula 
Nerve innervation: Medial pectoral nerve (C8-T1) 
 
Function: 
- Draws the scapula downward and forward into rib cage 
- Elevate ribs during abnormal breathing patterns or respiratory distress 

 Symptoms of pec minor spasm: 
  • Deep chest pain 
  • Unable to elevate shoulder, reaching forward and upward
  • Numbness through the inner arm, elbow, into wrist, hand and 4th and 5th  fingers 
  • Shoulder locked in “Guarding” position 
  • Same side neck rotation pain

Mechanism: 
  • Paradoxical breathing (chest breathing)  during respiratory distress. 
  • Overuse of pectoralis major (excessive push up exercise) 
  • Pectoralis minor tightness can be due to poor posture presented with rounded shoulder. 
 
Risk factor: 
  • Scoliosis 
  • Poor shoulder / posture
  • Chest breathing 
  • Excessive exercise - push up
 
Pec Minor Tightness ​Test 
Lie down on bed, measure the distance between Tip of Shoulder from bed.
Pec Minor Stretch
Method 1:
Stand at the wall corner (as shown), put both palms on the wall and elbow in 90 degrees.
Move your body forward close to the corner.
Hold for 15s, repeat 3 reps, or more.
Method 2:
​Holding both hands together at your back, and stretch it as far back as possible. 
Hold for 10-15s, repeat 3 reps, or more.
Can do it in walking, standing or sitting position.