This is an issue that deserves attention, as research examining iron levels in Americans shows that more people have iron levels that are considered too high, than levels that are deficient. In one study of more than 1,000 people, only 3 percent were iron deficient, but 13 percent had iron overload. 1. What are the Health Risks of Too Much Iron?
Think rigid. Rigidity is a condition of hardness, stiffness or inflexiblity. You find this with muscle contractures. Now think spastic. Spasticity is a form of muscular hypertoncity (excessive muscle tone) with increased resistance to stretching. It usually occurs in the flexor muscles of the arms and legs. You would see movement that requires greater effort and with a lack of control and coordination.
I was told spasms are a subset of spasticity, although many (including a few docs) used them as meaning the same thing. Wikepedia states: Spasticity or muscular hypertonicity is a disorder of the central nervous system (CNS) in which certain muscles continually receive a message to tighten and contract.