Final answer:
Static muscular effort is when muscles exert force without movement, such as holding a posture, while dynamic muscular effort is when muscles contract to move a body part, such as walking or lifting. The musculoskeletal system functions similarly to a lever system, employing these types of effort for various tasks.
Step-by-step explanation:
In terms of ergonomics, static muscular effort refers to muscles exerting force without changing length or moving the body part they are attached to. This type of effort is common when a person maintains a posture or holds an object still. In contrast, dynamic muscular effort involves muscles contracting and pulling on bones to generate movement, hence changing the length of muscle fibers. When muscles move body parts through their range of motion, such as when walking or lifting objects, this type of effort is at play.
The musculoskeletal system mimics simple lever systems, where bones serve as levers, joints as fulcrums, and muscle contractions as forces that either hold (static effort) or move (dynamic effort) loads. For instance, as the biceps muscle exerts force to hold up a book, it showcases a static effort. When the same muscle contracts to lift the book, it's employing dynamic effort. The mechanical advantage, forces, and torques involved in these actions can be analyzed through statics and provide insight into everyday strains on our muscles and bones.