Section 29. No compensation pursuant to section thirty-four or thirty-five shall be paid for any injury which does not incapacitate the employee from earning full wages for a period of five or more calendar days. If incapacity extends for a period of twenty-one days or more, compensation shall be paid from the date of onset of incapacity. If incapacity extends for a period of at least five but less than twenty-one days, compensation shall be paid from the sixth day of incapacity. Except as otherwise provided in this chapter, no compensation shall be paid for any period for which any wages were earned. No mental or emotional disability arising principally out of a bona fide, personnel action including a transfer, promotion, demotion, or termination except such action which is the intentional infliction of emotional harm shall be deemed to be a personal injury within the meaning of this chapter.