the fascination of the lower arm

have you ever observed how finger movements activate your lower arm? I am currently fascinated by that ... in sitting position put your right hand on your left shoulder and the ellbow on the table in front of you so your eyes watch your lower arm. Now start drumming on your shoulder with our fingers - index to small. all of them or individual ones... I think t'is fascinating how the arm flexes and moves ... and yes I am still in the library and still trying to read Judith Butler's reading of Levina's idea of the 'face' and our killing instincts ... so forgive me for getting a little weird ...