Function:
The human thumb is the opposable. It is useful for holding, for taking grasp or holds the thing, useful for fine motor skills. Thumb is very important for writing, drawing, painting etc.
Diseases:
Thumb diseases are not so common, but some genetic diseases like clubbed thumb may cause problem. Neuralgic complaints may affect your fingers along with thumb.
Interesting facts:
The thumb is controlled by nine individual muscles, which are controlled by all three major hand nerves. Thumb moves in such a complex fashion that almost ninety percent of women and 80 percent of men in the age group of 75-79 years have x-ray evidence of osteoarthritis in their hands. Your thumb is the same length of your nose.
