Hi Mark,
About 4 yrs ago, both before and after I had had 2-3 blocks, my arm had tremors or should I say, jerking so bad that if you stood in front of me you took a chance on being hit in the face !!

My arm would be up against my body by my waist and it would jerk out far from my body & upwards. It went away after a few more blocks, but I have jerks in all 4 extremities now, however not as severe as you describe. It happens more as I am relaxing,
when I'm having a lot of pain or too much activity. I'll jerk or have tremors or both.
Here is one article I found describing this: Wh

http://www.rsdalert.co.uk/FAQ/isshakingasymptom.htm

"Yes, tremor (shaking) is among the symptoms identified in studies on RSD/CRPS. No two cases of this condition are exactly alike, and some people see very few of the so-called "characteristic" symptoms, while others get the whole book! Tremors may be aggravated when the patient is over-stressed or tired because the sympathetic nervous system reacts to these conditions...." go to the site to read more.

The association of postural tremor with reflex sympathetic dystrophy (RSD) has been reported....and my research shows it could also be related to your neck injury when you were in the cab accident.

Also dr hooshmnds puzzle says it is common.
www.rsdrx.com/rsdpuz4.0/puz_128.htm

Hey! He's not always wrong is he ??

Hope