arm pain

Below is a link to a video of me making four movements with my right arm.
The first two movements do not hurt.
The second two movements produce a sharp, hollow pain in my upper arm.This pain comes and goes and has dogged me for at least 7 years.
It has also manifested sometimes in my other arm.Any ideas on what it could be?sensored://s112.photobucket.com/albums/n194/holyjes/?action=view&current=57a0ce1e.pbr