Hi Jeff,
I very much appreciate the material on Qi Striking Phenomenon.
I have experienced shaking, initially in both arms, from the shoulder usually but sometimes just from the elbow since taking up Vipassana in the mid-1990s. I didn’t have a clue about what was going on and the instructors at that time weren’t aware of it either. I did finally get the good advice to treat it as any other transient phenomena to ‘observe and watch it arise and pass away.’
I experience large jerking arm movements (in my left arm) as well as shorter, higher frequency oscillations in both arms (from the elbows) almost every session (meditation or magnification). I also often, but not everytime, experience a single arm jerk (a ‘flying’ left arm) when I feel moderately deeply inspired by words or emotion throughout the day whether meditating or not. I have let go of strong selfconsciousness about this and all but let go of moderate selfconsciousness (it might appear that I have some neurological problem to those observing the movements). I used to want to sit in the back of the room when practicing with others that don’t know me, and these movements. These days I figure that if they’re in the room, they’re gonna be, if not already okay with seeing such phenomena. I watch my self-consiousness about it arising and falling off as much as the phenomena in itself.

I have not found any content in the Week Three Lecture, section 4.1 and section 4.6 doesn’t want to cooperate with loading either.
Thank you,
David