The muscle proteome reflects changes in mitochondrial function, cellular stress and proteolysis after 14 days of unilateral lower limb immobilization in active young men

When humans are immobilized for 14 days, their muscle volume decreases by 2-3%.

In healthy young men, wearing a knee brace for 14 days without movement leads to a 9.6% loss in thigh muscle size, a 3.3% loss in leg muscle mass, and a 15.6% loss in leg press strength.

In healthy young men, immobilizing one knee for 14 days does not alter protein patterns in the muscle after three days; changes in protein expression only become detectable after longer periods of inactivity.

During 14 days of leg immobilization in healthy young men, muscle breakdown occurs without increased activity of two known protein-degrading enzymes called MuRF1 and MAFbx, suggesting other molecular mechanisms are primarily responsible for the muscle loss.

In healthy young men, 14 days of immobilizing one knee changes the levels of 99 proteins in the skeletal muscle, with 76 increasing and 23 decreasing, resulting in a significant shift in the muscle's protein profile.

In healthy young men, 14 days of immobilizing one knee changes 322 biological processes in the leg muscle: 77% increase in processes related to cellular stress and protein breakdown, and 23% decrease in processes related to mitochondrial function and energy production.