Sudden stiffness in left arm and leg often when standing up from sitting position

Hi,
I been having this symptom for almost 2 yrs now, after sitting when i stand up my left arm and leg get stiff as of i have no control over them, and it happnes only for about 5 to 10 seconds then it goes normal. couple thing i wanna add mostly it happens when i am nervious, in public, or stressed and i also have migraine headaches for about a year now. i've tried to tell this to 3 diff doctors the only med i been given was for my headaches.

Usman