2.3 Causes of Injury & Injury Patterns

2.3 Causes of Injury & Injury Patterns

Domain 1C (causes of injury) and Domain 1D (injury patterns) are one teaching unit. The July 2025 CPSC Handbook rewrote the epidemiology you must carry into the exam. Older study guides and older handbook editions talked about falls as the overwhelming emergency-room story. Do not recite "79 percent of injuries are falls" as current 2025 handbook language. You may know that earlier editions emphasized falls as the dominant ER-injury mechanism. The 2025 text uses two different data streams, and they do not say the same thing.

How many children are hurt?

CPSC §1.7, citing the National Electronic Injury Surveillance System (NEISS) for all playground-equipment-reported injuries, states an average of over 190,000 estimated emergency-room-treated injuries annually from 2021–2023. The handbook introduction rounds the same burden as almost 200,000 injuries annually that required emergency-room treatment. Those are estimates of ER visits, not a census of every scrape, and not a death count. Neither NRPA nor CPSC publishes a single official "lives saved by CPSIs" figure; do not invent one.

NEISS is a probability sample of U.S. hospital emergency departments. It answers "about how many children reach an ER after a playground-equipment incident?" It does not, by itself, tell you whether the climber broke, the surface failed, or two children collided. That is why the handbook immediately adds a second source.

The 2009–2014 incident study (the 38 / 29 split)

The 2025 handbook then reports a different data set: a study of 1,775 playground equipment-related incidents reported to CPSC from 2009–2014, excluding incidents related to one recalled product. A footnote explains there were 1,239 reports out of 3,014 total incidents associated with that single recall; those were set aside so the remaining 1,775 could be classified. In that incident file:

• Equipment-related hazards — breakage, tip-over, design, and assembly — were the most common hazard pattern: 38 percent.
• Falls were next: 29 percent.
• Other common patterns included entrapment and colliding into other children or stationary equipment.

This is the split you must memorize for 2026. It is not a contradiction of "falls matter." It is a reminder that when CPSC investigators look at reported incidents — a set that includes deaths, severe events, and product defects, not only NEISS ER estimates — hardware failure and design or assembly errors outrank falls. An inspector who only rakes mulch and never looks at rusted welds, loose anchors, or a tip-over-prone post is inspecting the wrong half of the 2025 pattern.

Earlier CPSC handbook editions emphasized falls as the dominant mechanism among emergency-room injuries. That older "about four out of five ER injuries are falls" teaching is how many veteran CPSIs were trained. The July 2025 edition does not repeat that 79 percent figure. If a question stem says "according to the current CPSC Handbook," answer with over 190,000 / almost 200,000 ER injuries (NEISS 2021–2023) and the 38 percent equipment / 29 percent falls incident-study split.

How children die on playgrounds

Playground-related deaths reported to CPSC involved:

• Entanglement of ropes, leashes, bicycle helmets, or clothing with a drawstring
• Falls
• Impact from equipment tip-over or structural failure

Drawstrings on children's clothing are prohibited per 16 C.F.R. § 1120.3. The handbook footnotes that prohibition next to the death discussion. ASTM F1816 addresses drawstrings on children's upper outerwear. For the inspector, the field implication is: treat clothing-entanglement hardware — open S-hooks, bolt ends, catch points at the top of slides, gaps that can catch a helmet strap — as a life-safety issue, not a maintenance footnote. Ropes, leashes, and skip-ropes brought onto the playground are a classic entanglement vector; they are not "just a supervision problem."

Notice that deaths and ER visits do not rank the same way. Falls drive a large share of medical visits and still appear in the death file. Entanglement is a smaller share of everyday injuries and a leading share of deaths. That is why an open S-hook can outrank a scuffed platform in priority even when "nobody has fallen yet."

Mechanism mapped to control

Epidemiology is useful only if it changes what you look for and what you write.

Using patterns without over-claiming

Two discipline points keep you honest on the exam and in a report.

First, NEISS estimates and incident investigations answer different questions. NEISS estimates how many children reach U.S. emergency rooms. The 1,775-incident study classifies the hazard pattern in a CPSC investigative file after excluding a massive recall cluster. You can — and should — hold both numbers. You should not average them into a homemade percentage or replace one with the other.

Second, surfacing still earns its chapter. Section 1.6 still says that because falls are a very common playground hazard pattern, installing and maintaining protective surfacing is crucial to protect children from severe head injuries. The 2025 incident split does not retire F1292. It adds a duty: inspect for breakage, tip-over, and assembly or design defects with the same seriousness you give the surface.

When you write an audit finding, connect the mechanism to the control. "Loose-fill is 4 inches at the slide exit; fall-related head-injury risk; restore to the depth supported by the current F1292 report and F3313 test." "Swing-bay post has a failed footing; tip-over pattern in the 38 percent equipment-related cluster; take out of service and re-anchor." That is how Domain 1C and 1D show up in later audit, maintenance, and risk-management work.