Forearm and leg is divided into compartments by membranes. In case there is increase in the pressure in the compartments such as post fracture, it results in compression of the contents. this condition is called compartment syndrome. The nutritional supply to the constituents is cut down. The condition is said to present with " 6 P's ". These are: 1) pain which is excruciating and out of proportion 2) pallor of the area and distal to it 3) pressure higher than 15mmHg in leg 4) paresthesia 5) paralysis due to damage to nerves 6) pulseless because of compression of vessel.