Methods and devices to reduce the likelihood of injury from concussive or blast forces

1. A system comprising:

a first device;

a second device;

wherein each device has an appropriate size and shape to restrict blood flow egressing from the head of a subject when the devices are placed against the neck of the subject; and

a garment having:

a shoulder region structured to be shoulder worn by the subject,

an opening at a laryngeal prominence of the subject when worn by the subject, and

a collar region made of an elastic material,

wherein the collar region is configured to receive the first and second devices so that, when the garment is worn by the subject, the first and second devices are positioned over a respective one of a pair of neck veins of the subject, and

wherein the elastic material is configured to exert sufficient pressure on the first and second devices so that, in combination, the first device, the second device, and the elastic material apply a compressive pressure to the pair of neck veins to restrict blood flow egressing from the head of the subject while the garment is worn by the subject.

2. The system of claim 1 , wherein the first and second devices each comprise an inflatable bladder.

3. The system of claim 2 , wherein each inflatable bladder further comprises a pressure release valve.

4. The system of claim 2 , wherein each inflatable bladder further comprises a pump.

5. The system of claim 1 , wherein the first and second devices each comprise a protuberance.

6. The system of claim 5 , wherein each protuberance comprises an inflatable bladder.

7. The system of claim 6 , wherein each inflatable bladder further comprises a pressure release valve and/or a pump.

8. The system of claim 1 , wherein each of the first and second devices is a rigid plastic body.

9. The system of claim 1 , wherein each of the first and second devices is a semi-rigid plastic body.

10. The system of claim 1 , wherein the pair of neck veins comprise internal jugular veins.

11. The system of claim 1 , wherein the pair of neck veins comprise external jugular veins.

12. The system of claim 1 , wherein the compressive pressure is from 5 mm Hg to 80 mm Hg.

13. The system of claim 1 , wherein each of the first and second devices further comprises an adhesive positioned to contact a neck of the subject.

14. The system of claim 1 , wherein the first and second devices are integral to the elastic region.

15. The system of claim 1 , wherein the first and second devices are removable from the elastic region.

16. The system of claim 1 , wherein the first and second devices are attached to one another by a resilient arcuate band sized to encircle a portion of a neck of the subject.

17. The system of claim 16 , wherein the resilient arcuate band is configured to encircle the neck of the subject except for an area substantially defined by the laryngeal prominence of the subject.

18. The system of claim 16 , wherein the resilient arcuate band comprises a semi-rigid shape-memory material.

19. The system of claim 16 , wherein each of the first and second devices define a thickened region of the resilient arcuate band.

20. The system of claim 16 , wherein each protuberance is defined by an outward bend point of the resilient arcuate band, wherein the resilient arcuate band has a shape selected from a group consisting of C-shape, a V-shape, and a U-shape.

21. The system of claim 1 , wherein the compressive pressure is in a range sufficient to restrict blood flow egressing from the head of the subject through the pair of neck veins.

22. The system of claim 1 , wherein the compressive pressure is sufficient to compress the pair of neck veins enough to cause an increase in venous resistance of the subject, yet not enough to increase an arterial pressure leading into a cranium of the subject.

23. The system of claim 22 , wherein the pair of neck veins are outflow vessels.