Muscle Control
Your arm and/or hand muscles don’t always act the way you wish, sometimes never doing so. A muscle may be permanently contracted or lacks fine motor control. IE serves as a guideline for specific effects and generally a −(IE) penalty on all Strength checks and saving throws and attacks. Spells with somatic components usually need to be modified to work within your physical range, requiring a day for every hour normally needed to inscribe into your spellbook and double the cost due to experimentation materials.
Real-world Examples
Cerebral Palsy, Muscular Dystrophy, Multiple Sclerosis, Spina Bifida, Amyotrophic Lateral Sclerosis, Arthritis, Parkinson’s Disease
Assistive Options
No mundane technology can normally assist with this, but be creative.
Magical Assistance
The Telekinesis or Mage Hand spells and items that duplicate their effects can assist with this for minor tasks.