The intrinsic muscle adaptations after disuse

Abstract

Background: Disuse results when muscles are exposed to inactivity. Intrinsic muscle changes like fiber-type shift, decreased cross-sectional area (CSA) or muscle mass will occur. Inactivity is commonly seen in people with a certain condition or illness. Therefore, it is important for rehabilitation purposes to know how these changes occur, to what extent and which impact disuse has on the short- and long-term. Results: Eight-teen (EAE1) and 28 (EAE2) days of disuse resulted in significantly lower tetanic. A significant decrease in force after the FAT-protocol is seen for EAE2 and DOSCAR compared to CON. The decrease was larger and occurred faster in the DOSCAR group. Conclusion: Fifty-six days of disuse showed a greater decrease in active force compared with EAE groups and CON after a fatigue-protocol. Therefore, the resistance to withstand fatigue is decreased (DOSCAR), which can infer that the duration of disuse plays a significant role in active force.