What is a common effect of stress on the musculoskeletal system?

Muscle tension and pain are common effects of stress on the musculoskeletal system due to the body's physiological response to stress. When a person experiences stress, the body's fight-or-flight response is activated, which can lead to the tightening of muscles in an effort to prepare for perceived danger. This state of heightened muscle tension can result in discomfort or pain, particularly in areas that are commonly affected by stress, such as the neck, shoulders, and back.

Over time, this persistent muscle tension can contribute to various issues, including tension headaches and chronic pain conditions. In contrast, joint dislocation is typically the result of physical trauma rather than stress, and reduced muscle tone or increased flexibility is generally not associated with stress. Instead, heightened muscle tension is a more accurate reflection of the body's response under stress, reinforcing why this answer is the correct choice.