Important Muscles with their Insertion, Origin, and Action
| Front | Masseter |
| Back | O=zygomatic arch and maxillaI=Angle and ramus of mandibleA=Close jaw (Prime mover) |
| Front | Splenius |
| Back | O=Spinous processesI=Mastoid process and occipital boneA=Extend or hyperextend head |
| Front | Triceps brachii |
| Back | O=Inferior margin of glenoid cavity, posterior humerus, and groove on posterior humerusI=Olecranon processA=Extend forearm |