If an elderly patient undergoes prolonged bed rest following hip replacement surgery, which consequence most directly accelerates sarcopenia in the immobilized leg?

💡 Explanation

Sarcopenia accelerates because prolonged bed rest decreases muscle protein synthesis. The mTOR signaling pathway is crucial for stimulating protein synthesis in response to mechanical stimuli and nutrient availability; therefore, decreased mTOR signaling directly reduces muscle growth and maintenance, rather than the other proposed mechanisms which play indirect roles.

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