What is the typical weekly loss of muscle strength during complete bed rest?

What is the typical weekly loss of muscle strength during complete bed rest?

• A. 10-15% per week
• B. 1-2% per week
• C. 50% per week
• D. 0% per week

Answer: (A)

Disuse atrophy from complete bed rest causes the muscles to lose strength quickly because they aren’t loaded and used. When loading stops, neural efficiency declines and muscle fibers shrink, with protein balance shifting toward breakdown. The commonly observed rate is about 10-15% of strength lost each week of immobilization. This magnitude explains why weakness can develop rapidly during a hospital stay and why rehabilitation emphasizes early, progressive loading to restore strength. If the weekly decline were only 1-2%, the weakness from bed rest would be far less noticeable; if it were 50% per week, we'd expect near-total loss in days; zero decline is incompatible with immobilization.

Disuse atrophy from complete bed rest causes the muscles to lose strength quickly because they aren’t loaded and used. When loading stops, neural efficiency declines and muscle fibers shrink, with protein balance shifting toward breakdown. The commonly observed rate is about 10-15% of strength lost each week of immobilization. This magnitude explains why weakness can develop rapidly during a hospital stay and why rehabilitation emphasizes early, progressive loading to restore strength.

If the weekly decline were only 1-2%, the weakness from bed rest would be far less noticeable; if it were 50% per week, we'd expect near-total loss in days; zero decline is incompatible with immobilization.