Why do the leg muscles of a paraplegic spasm even though there is no feeling?.
After a spinal cord injury, when nerves below the injury become disconnected from those above, the responses become more extreme. Muscle spasms, or spasticity, can occur any time the body is stimulated below the injury. .
My hypothesis is that even though the nerves are damaged, and possibly cut, the damaged area may still be transmitting some type of an electrical impulse.
My experiment consisted of applying certain objects such as ice cubes, a sharp metal object, a cotton ball, and tapping a news paper on the muscle to see the reactions.
First I applied an ice cube to the muscle. The result was that the muscle began to spasm. I repeated this step seven times. I found that the longer the ice cube was on the muscle the more frequently it began to spasm. .
Secondly I poked the muscle with a sharp metal object seven times. The reaction was only when the object was applied with some pressure that the muscle would spasm for approximately three to four seconds. Three out of seven times the muscle had this reaction. Four out of seven times the muscle did not react.
Third I rubbed a small cotton ball on the muscle. I repeated this 7 times. There was no reaction at all any of the times I tested it.
Fourth I tapped a news paper on the muscle. About one to seconds after I would tap the muscle with a newspaper it would spasm one to three times. I tested this seven times, and I found the four out of the seven times the muscle spasmed. .
This experiment demonstrated how different objects would make the muscle react. Through this I learned that the ice cube had the greatest effect on the muscle and the cotton ball had the least effect on the muscle.
I too learned to that this is mostly noticeable when there is something irritating the muscle below the injury. When small amounts of pain or other sensations from the body are transmitted to the spinal cord the disconnection between the nerves and the brain causes the muscles to contract or spasm.