American Academy of Professional Coders (AAPC) Practice Exam

Which muscle type is primarily involved in human posture and body movement?

1. Skeletal muscle

2. Cardiac muscle

3. Smooth muscle

4. Visceral muscle

The correct answer is: Skeletal muscle

Skeletal muscle is primarily involved in human posture and body movement due to its unique structure and function. These muscles are attached to bones by tendons and enable voluntary movements, which play a crucial role in maintaining posture and executing a wide range of physical activities. Skeletal muscle fibers are striated and can contract rapidly, allowing for the precise and controlled movements needed for tasks such as walking, running, and lifting. The other muscle types have different roles in the body. Cardiac muscle is found only in the heart and is responsible for pumping blood throughout the circulatory system. While it is essential for circulation, it does not contribute to posture or voluntary movement. Smooth muscle is located in the walls of hollow organs, such as the intestines and blood vessels, and is responsible for involuntary movements, like peristalsis and constriction of blood vessels. Visceral muscle is a term often used interchangeably with smooth muscle, referring to the same type of muscle found in internal organs, which also does not play a role in posture or voluntary body movement. Thus, skeletal muscle is distinctly recognized for its vital function in body movement and posture.