What is the primary function of skeletal muscles in the human body?

Skeletal muscles play a crucial role in facilitating movement within the human body. Their primary function is to contract and relax, which enables the movement of bones and joints. When skeletal muscles contract, they pull on tendons that are attached to bones, resulting in movement. This process allows individuals to perform a wide range of activities, from simple actions like walking and grasping objects to more complex movements required in athletics and dance.

Additionally, skeletal muscles contribute to maintaining posture and body alignment by working continuously to keep the body stable. While skeletal muscles may have some roles in protecting internal organs to a degree, their main and most critical role is in enabling voluntary movement. The other options listed provide important functions for different structures in the body but do not encompass the primary role of skeletal muscles in facilitating movement.