Final answer:
In ergonomics, the back is one of the highest risk body parts due to its complex structure, necessitating the back muscles to exert large forces, often leading to issues such as crushed discs. Jaws may also be considered at risk although they were not discussed in detail.
Step-by-step explanation:
In terms of ergonomics, some body parts are considered to be at higher risk for injury due to the physical demands placed upon them in various work and daily life activities. Among these, the back is often regarded as one of the highest risk areas. This is owing to its complex structure, which includes numerous muscles, joints, and vertebrae, all operating with mechanical advantages that are less than one. The back muscles are thus required to exert considerable forces to perform movements, support the upper body, and maintain posture. The spinal column bears not only the weight of the upper body but also the additional forces created by these muscles. Consequently, issues like discs being crushed by exertion are not uncommon. It's also worth mentioning that the jaws can also be subjected to ergonomically-related risks, although the specifics of jaw risks were not detailed in the provided information.
This focus on high-risk areas in ergonomics is essential for designing workspaces, tools, and tasks that minimize strain and reduce the chance of injury. By understanding which parts of the body are most vulnerable, ergonomists can help create safer and more comfortable working environments.