Quadriceps Setting. This exercise helps to strengthen the quadriceps muscle (the big muscle on the front of the thigh), an important stabilizer of the knee. click to enlarge. Lie on your back with the leg you want to exercise straight. Place a small rolled towel underneath the knee.
Hallucinogens can cause an excited catatonic state, including 3,4-methylenedioxymethamphetamine (ecstasy) and phencyclidine (angel dust). Carbon monoxide poisoning can cause catatonia due to damage to the basal ganglia.
1 If the plasma Ca2+ decreases to less than 50% of the normal value of 9.4 mg/dl, action potentials may be spontaneously generated, causing contraction of peripheral skeletal muscles. Hypocalcemia is not a term for tetany but is rather a cause of tetany.  The usual cause of tetany is lack of calcium.