A new type a lightweight and pressurized neck collar may help prevent mild concussions during sports, according to the developers of the device.
The collar, which weighs four to five ounces -- is designed to exert a minimal amount of continual pressure on the large neck veins that carry blood from the heart to the head, and back again.
That slight pressure, which is similar to the pressure of a tie knot, triggers a slight drop in the amount of blood that flows out of the head.
