In this article. Spasticity is a muscle control disorder that is characterized by tight or stiff muscles and an inability to control those muscles. In addition, reflexes may persist for too long and may be too strong (hyperactive reflexes).n this article. Spasticity is a muscle control disorder that is characterized by tight or stiff muscles and an inability to control those muscles. In addition, reflexes may persist for too long and may be too strong (hyperactive reflexes).
US actor Ethan Cutkosky (of Shameless) is 17 years old (born August 19, 1999).
3. How old is Noah Schnapp? Noah Schnapp, (born October 3, 2004) is 13 years old. In season 1 of 'Stranger Things', the character Will Byers is 12 years old. 12 images See the full gallery: How Old Are The 'Stranger Things' Cast And Characters In Real Life?