6.5months outdated and exceedingly straight arm?

My daughter is 6 and a half months old and for a while now I hold noticed she keeps her right arm poker straight during the day. Its not adjectives the time but pretty reguarly...
She does use both arms and hands equally but its defiantely something Ive noticed.
Can anyone give me any information or put my mind to rest on what it might be or does anyone elses infant do the same?

Answers: Could be some sort of muscle spasm-see the Doc !

Doctors?