My spasticity often lasts for days, whether a leg cramp or hand cramp. I finally figured out what it was after reading and reading about other folks' symptoms.

I was of the mind that it was arthritis, after years of outdoor work and wrapping my hands around paddles and gripping ropes while hanging on for dear life...LOL. I worked March to November regardless of the weather and I figured I was paying for it in middle age for having so much fun!

I have a Tupperware shaker cup, the lid is easy to lock down even while having major grip problems, it has a flip top lid that opens and closes easily. I think they sold them as an instant shake and pudding mixer, because it came with a blender wheel inside it.

I use this ALL the time. It has measuring lines on the side. You can use it to drink from, to measure with, to blend spices and gravies, literally anything that needs to be mixed.

I think Rubbermaid makes a version, and probably several others have knockoffs, but the Tupperware cup seal hasn't failed yet, and it has to be ten years old!