What condition may result from prolonged inactivity in elderly patients?

Prolonged inactivity in elderly patients is associated with a range of complications, one of which is pneumonia. Inactive individuals are less likely to take deep breaths and expand their lungs fully, increasing the risk of fluid accumulation and the development of pneumonia. This condition is particularly concerning in elderly patients, who may already have compromised respiratory function or other comorbidities that can further increase their susceptibility to infections.

The other options do not accurately reflect the potential outcomes of prolonged inactivity. Increased muscle strength and enhanced joint mobility are typically the results of physical activity and exercise, not inactivity. Likewise, inactivity usually leads to a decrease in metabolic rate rather than an improvement. Therefore, pneumonia is the correct choice as it highlights a critical health concern related to the effects of prolonged inactivity.