Spasticity is a neurological movement disorder that causes muscles to feel tight or stiff, which can make it hard to move or control certain parts of your body. It happens when there’s a problem with the signals between your brain, spinal cord and muscles.
Spasticity is a common symptom in people with certain neurological conditions, such as:
Normally, your muscles work together so that when one tightens, the other relaxes. But when the brain or spinal cord is damaged, this system doesn’t work the way it should. Instead, many muscles can tighten all at once, which can make movement feel jerky, stiff or hard to control.