Synergists Trunk & Thorax

Question 1

Spine Flexion

Answer 1

Rectus abdominis
External oblique (bilaterally)
Internal oblique (bilaterally)

Question 2

Spine Extension

Answer 2

Spinalis (bilaterally)
Longissimus (bilaterally)
Iliocostalis (bilaterally)
Multifidus (bilaterally)
Rotatores (bilaterally)
Semispinalis capitis
Quadratus lumborum (assists)
Intertransfersaii (bilaterally)
Interspinalis
Latissimus dorsi (when arm is fixed)

Question 3

Spine Rotation

Answer 3

Multifidi (to the opposite side)
Rotatores (to the opposite side)
External oblique (to the opposite side)
Internal oblique (to the same side)

Question 4

Spine Lateral Flexion

Answer 4

Spinalis (unilaterally)
Longissimus (unilaterally)
Iliocostalis (unilaterally)
Quadratus lumborum (unilaterally)
External oblique (unilaterally)
Internal oblique (unilaterally)
Intertransversaii (unilaterally)
Latissimus dorsi (unilaterally)

Question 5

Ribs/Thorax Elevation (Expansion)

Answer 5

Anterior Scalene (bilaterally)
Middle Scalene (bilaterally)
Posterior Scalene (bilaterally)
SCM (assists)
External intercostal (assists)
Serattus posterior superior
Pectoralis major (if arm is fixed)
Pectoralis minor (if scapula is fixed)
Serratus anterior (if scapula is fixed)

Question 6

Rib/Thorax Depression (Collapse)

Answer 6

Internal intercostals (assists)
Serratus posterior inferior