What is a non-respiratory factor that can limit diaphragm movement?

The correct answer highlights advanced pregnancy as a non-respiratory factor that can limit diaphragm movement. As the pregnancy progresses, the growing uterus exerts pressure on the diaphragm, which can restrict its movement and decrease the efficiency of breathing. This physical displacement can alter the mechanics of respiration, leading to potential issues such as shortness of breath or difficulty taking deep breaths as the diaphragm's natural range of motion is constrained.

While other choices may have implications for an individual's overall health or could indirectly affect respiratory function, they do not directly impact the diaphragm's mechanical capability in the same way that advanced pregnancy does.