Answer: You probably either injured the nerves directly due ott he vibration or caused swelling of the hands and wrist which is not pinching a nerve (carpal tunnel syndrome). If you do not continue to use the hands in a repetitive manner (such as typing) it will most likely go away.
Answer: Most likely the muscle tics are caused by stress or fatigue.Drinking lots of coffee or taking other stimulents could also causeit. but it is also possibly caused by less common but more seriousmedical conditions. So if it continues for a long time or getsworse, see a physician.
Answer: It is called the third finger, or by hard analysis "the Saturn finger."In terms of a medical reference, it would be broken into 4 parts; the metacarpal, proximal phalange, intermediate phalange, and distal phalange