Hmmm. All new ones on me!
I thought spasticity was muscular resistance to movement - specifically, resistance that increases proportionally to how fast you try to move.
So you might be able to execute a movement slowly, but if you try to do the same thing suddenly, the muscle will resist it.
I’ve always considered that I have spasticity, but perhaps I’ve been wrong all these years, as it has never manifested as limbs locking into position. I do get the latter occasionally, as part of very severe cramps, which typically begin in a foot, then shoot all the way to the groin, immobilising the entire leg.
Whilst I know that cramp and spasticity are all related (and I take Baclofen for both), I’ve always regarded them as two different things.
The spasticity, unlike the cramp, is with me all the time, and manifests itself as abnormally high resting muscle tone (my calves look like I work out - a lot - and they got that way all by themselves, post 40!), with pain, stiffness, and resistance to movement. I can actually feel the abnormal tone of the muscles too - i.e. if I massage them, they are very dense and rock-like - not much suppleness. They look really cool, but work really terribly - appearances can be deceptive!