User:Michael Toscano/sandbox
Sarcopenia
Sarcopenia (from Greek) literally translates as poverty of flesh (2) and is used to describe a disease that results in the reduction of skeletal muscle mass and the loss of strength (1,2,3,4,5). In clinical studies, sarcopenia is often a qualitative inspection for small muscle mass and is widely considered one of the major causes of age-related disabilities (1). Sarcopenia reflects a progressive withdrawal of anabolism and an increased catabolism. This disease also reduces the muscles ability to regenerate, due to a decrease in satellite cell numbers (4).
Classification of Sarcopenia
Sarcopenic classification of individuals requires a measure that expresses muscle mass in relation to skeletal size and sex-specific criteria to determine a deficit in skeletal muscle mass. The elderly have less muscle mass and less bone mass along with expanded extracellular fluid volumes and a smaller amount of body cell mass compared to that of younger adults (3). A decrease in skeletal muscle mass is associated with a significant decline in the maximum force that can be exerted. This suggests that the quality or efficiency of skeletal muscle is reduced with age (5). In earlier studies, sarcopenia was examined in individuals by observing and testing calf muscle (1), and other muscle cross sectional areas for change in muscle function with aging and how it affected mobility in men and women (1,2,3,4). Also tested were the participants’ knee extension (1,2,4), handgrip strength (1,2,3), plantar flexor and dorsiflexor muscles of the foot (2), and lower extremity muscle power. Sarcopenia is considered to be present when the measurement of each of these indicators was greater than two standard deviations below the mean of the experimental group’s data (1,2,3,4). The loss of skeletal muscle mass directly impacts and is correlated with age-related declines in strength. Studies have shown that between the ages of 20 and 60 years old, total muscle cross section areas (CSA) decreases by about 40%. This includes a reported 25-35% CSA reduction of the quadriceps muscles in the thighs of older men and women when compared to a younger control group (2).