I also found that if I have one foot(obviously the one not used for the pedal)on a book or something like it releives the tension. I know it is recomemded to keep feet flat on the floor, but that bothers me more. I would sit with my legs curled up on the chair if I could figure how to operate the foot pedal...LOL...
Be sure your arm from finger tips to elbow are parallel with the floor.