What does the term "muscle atrophy" refer to?

Muscle atrophy specifically refers to a decrease in muscle mass that occurs when muscles are not used or stimulated sufficiently. This condition can arise from a variety of factors, including prolonged inactivity, illness, malnutrition, or certain medical conditions. When muscles are not regularly engaged in activity or exercise, they begin to lose size and strength due to the breakdown of muscle fibers and insufficient protein synthesis.

This concept is particularly important in the context of rehabilitation, physical therapy, and fitness training, as it highlights the need for regular movement and exercise to maintain muscle health. Understanding muscle atrophy is essential for developing effective training programs and preventing deterioration of muscle tissue, especially in populations that may be at higher risk, such as the elderly or those recovering from injury.