The vulnerable spots are the life giving spots of human body. According to the 'SidhaVaidya', which is a Dravidian science of medicine, in human body there are 108 vulnerable spots and 51 anti vulnerable spots. If any injury occurs in the vulnerable spots, then we will have loss of consciousness, fatigue and convulsions. Those who lose consciousness like these we can bring them back to the original state by knocking the anti-vulnerable spots (Adangal). If we don't do this they may die or may become handicapped.

These types of application to the vulnerable and anti-vulnerable spots are described in the southern system which is the Dravidian art of warfare. In Naalumantra and Bheeman vazhi importance is given to this type of training. But today, those who know about these are very rare.

Since this is a very dangerous type of application the guru used to teach this only to those disciples who are noble and trust worthy. According to scientific books this knowledge which was created by Lord Siva reached man kind through saint Agastya with Lord Subramanian's favour. Divine persons like Agastya, Bhogar and Therayar have described in the books of Marmashastra that the science of vulnerable spot should be taught only to those disciples who carry out the instructions of guru patiently for 12 years and after taking the apt gift from him.