A trauma pad, also sold as a trauma pack, trauma plate or backer, is an insert worn behind a ballistic panel. This article sets out what the records say about trauma pads, what NIJ testing does and does not cover, and what to ask before adding one. ArmorList reports what the records show; it never ranks or endorses a product.
What a trauma pad is meant to do
When armor stops a bullet, the bullet still pushes the armor into the body behind it. The injuries this can cause are called blunt trauma. CJTTEC, the center that runs NIJ's Compliance Testing Program for body armor, describes trauma packs and plates as intended to reduce blunt force trauma injury to the torso resulting from a bullet striking the armor.
A trauma pad does not stop bullets on its own and is not a substitute for the ballistic panel. It sits behind the panel, not in place of it.
What NIJ tests, and what it does not
NIJ tests and lists armor by model, and a listing covers that model as tested. CJTTEC states that the Compliance Testing Program does not test trauma packs or plates, either separately or in conjunction with soft armor models.
CJTTEC says two more things about accessory panels, such as groin and coccyx panels, which the program also does not test:
- A manufacturer may have an accessory panel tested at an NIJ-approved laboratory, but the results stand on their own and are not certified by NIJ.
- An accessory panel should never appear in a catalog or on a website designated as "NIJ Level" anything. In our view, the same caution applies to a trauma pad, which the program does not test either.
So a trauma pad has no NIJ level and no entry on the NIJ Compliant Products List (CPL). A claim that one does cannot be checked against the list.
Backface signature: what the armor test measures
Blunt trauma is not ignored in testing. It is measured on the armor itself. Under NIJ Standard 0101.06, armor is shot over a clay backing, and the depth of the dent the armor leaves in the clay, called backface signature, is measured against a maximum. The 0101.06 standard sets that maximum at 44 mm, with a statistical allowance above it and an absolute limit of 50 mm.
The National Academies traced the 44 mm figure to animal studies from the 1970s that related the depth of deformation behind armor to the risk of serious injury. NIJ's current body armor standard is 0101.07; this article does not restate its test procedures.
What this means for a pad: the backface signature in a model's test was measured on the armor as submitted. A pad added later was not part of that measurement unless the manufacturer tested it that way.
What the research says about blunt injury behind armor
- NIJ funded a pilot study, with Wayne State University and the IACP/DuPont Kevlar Survivors' Club, on blunt force injuries from bullets that struck but did not penetrate armor: bruising, lacerations and internal injuries. It looked at whether the standard of the time was effective in preventing serious chest injuries.
- A 2008 paper in Forensic Science International described a "backface signature injury": open wounds under armor even though the bullet did not penetrate. It found that most of the Zylon-containing vests tested deformed beyond the 44 mm limit of the earlier 0101.04 standard, and said the underlying cause of these injuries was unknown.
We found no government or peer-reviewed source that measures how much a trauma pad reduces injury, or that states a pad prevents a specific injury (checked 29 September 2026). This article makes no such claim.
Fit, placement and care
These are our position, stated as ours, and they defer to the manufacturer:
- Follow the armor manufacturer's instructions on whether a pad may be used with that model, and where it goes.
- A pad should not push the ballistic panel out of position or reduce its coverage. Recheck fit with the pad in place, standing, seated and moving.
- Replace a pad on the manufacturer's schedule, or sooner if it is damaged.
For the armor itself, CJTTEC's care guidance is to store it flat in a dry, shaded place, avoid extreme heat or cold such as a vehicle trunk, air-dry panels flat without folding, and never machine-wash them.
What to check
- Is the ballistic panel's exact model on the NIJ CPL, and on what date did you read its status?
- Does the armor manufacturer allow a trauma pad with that model, and was the model tested with one?
- If a pad claims test results, which laboratory issued the report, to which standard, and on what date?
- Does the pad claim an "NIJ Level"? The program does not test trauma pads, so that claim cannot be checked against the list.
A trauma pad has no NIJ level. Check the armor model on the CPL, ask the manufacturer how the pad fits that model, and keep the date you read each record.
Sources
- CJTTEC, Body Armor FAQs (read 2026-09-29)
- NIJ, Compliant Products List: Ballistic Resistant Body Armor (read 2026-09-25)
- CJTTEC, Compliant Product Lists (read 2026-09-25)
- NIJ, Ballistic Resistance of Body Armor, NIJ Standard-0101.06 (read 2026-09-29)
- National Academies, Testing of Body Armor Materials: Phase III (2012), chapter 3, Historical Basis for Current Body Armor Testing (read 2026-10-01)
- Wayne State University, Establishment of Interdisciplinary Working Group for Review of Kinetic Energy Munitions, NIJ-funded final report (NCJ 236909, received December 2011) (read 2026-10-01)
- Wilhelm M, Bir C. Injuries to law enforcement officers: the backface signature injury. Forensic Science International, 2008 (PubMed) (read 2026-09-29)
- CJTTEC, Body Armor Care and Replacement (read 2026-09-29)