What would happen if the troponin and tropomyosin couldn't move in response to calcium

Troponin changes shape in response to calcium and moves tropomyosin off of the myosin binding sites on the actin molecules of the thin filaments of your muscle fibers.
The myosin heads on thick filaments can only bind to the thin filaments when these myosin binding sites are unblocked.
If there is no calcium present to change the conformation of troponin to move the tropomyosin off of these binding sites, the thick filaments cannot slide along the thin filaments and muscle contraction cannot occur.