| A | B |
|---|
| external oblique | flexion and rotation at waist |
| internal oblique | flexion and rotation at waist |
| transverse abdominis | compresses abdominal wall |
| rectus abdominis | flexion at waist |
| diaphragm | prime mover of inhalation flattens upon contraction |
| external intercostals | helps elevate rib cage; aids in inhalation |
| internal intercostals | depresses rib cage; aids in forced exhalation |
| pectoralis minor | draws scapula anteriorly and interiorly |
| trapezius muscles clavo-upper, acromio-middle spino-lower | extends head; elevates depress, rated and retracts scapula |
| levator scapulae | elevates and adducts scapula; flexes neck on same side |
| rhomboideus | retracts and rotates scapula |
