I am a 21 year old male, 160 pounds. I have noticed over the past 2 months or so that I get a sudden, powerful muscle spasm/shake/jolt/tremor in my hands (usually left, sometimes both), but it only happens when I am typing on a computer keyboard or on my cell phone. It happens about 1-5 times daily. Basically what happens is I'll be in the middle of typing, and suddenly my hand will uncontrollably jolt in any direction for just an instant (a second or less), then I regain normal control over my hands and can continue typing. Sometimes it is minor and the movement is minor, while other times it will look like my hands suddenly jerk into mid air while typing.
My hands do not shake or tremor at rest or during any other activities. I am generally healthy and have no other health issues, although I have a history of anxiety. I also want to note that I am a professional gamer and I must tightly grip my controller for many, many hours weekly, which often causes stress on my forearm and hand muscles.
I am driving myself crazy worrying about this being an early sign of Parkinson's or a neurological disorder. Can this truly be the result of overworking my forearm and hand muscles? Is it also related to anxiety? Any advice will be a great help.