What condition might a patient with prolonged bed rest develop due to disuse of muscles?

The condition that a patient with prolonged bed rest may develop due to disuse of muscles is muscle atrophy. This phenomenon occurs when muscles are not used over a period, leading to a decrease in muscle mass and strength. When muscles are inactive, they undergo a process where the body starts to break down muscle tissue, leading to a reduction in size and functionality.

This is especially significant for patients who are immobile for extended periods, as the lack of physical activity promotes this atrophy. It's a common concern in rehabilitation and physical therapy, as clinicians often focus on strategies to prevent or mitigate muscle atrophy in patients who are recovering from surgery, illness, or injury.

Other conditions mentioned, such as muscle hypertrophy, occur with increased muscle use and demand, while muscle rigidity and spasms are associated with different physiological responses rather than disuse. Hence, muscle atrophy is the most relevant to prolonged bed rest.