After I wrote my post, I suddenly realized those statements I made about explosive vs traumatic injuries were completely based on my impressions, not what the experts say.
I have worked in various aspects of healthcare, so I have a passing familiarity with a variety of things across the medical spectrum. I realized I had completely extrapolated what I knew, what I have experienced, what I have seen without knowing if it was even true. (generally not good to do unless you are aware you are doing it and can qualify it)
Anyway, I immediately got curious and thought "Is that true?" and looked it up. I came across a medical journal article: Patterns in Blast Injuries to the Hand
Here is the abstract:
Blast injuries to the hand are not just a wartime phenomenon but also quite common in rural communities throughout northern California. The purpose of this study is to review our experience with blast injuries in the community and review the most common patterns in an attempt to identify the pathomechanics of the hand injury and the reconstructive procedures that are required. This is a retrospective study of blast injuries to the hand treated between 1978 and 2006. Medical records, X-rays, and photos were reviewed to compile standard patient demographics and characterize the injury pattern. Explosives were classified based on their rate of decomposition. Reconstructive solutions were reviewed and characterized based on whether damaged tissues were repaired or replaced. Sixty-two patients were identified with blast injuries to their hand. Patients were predominantly male (92%) with an average age of 27 years. Firecrackers were the most commonly encountered explosives. Thirty-seven patients were identified as holding a low explosive in their dominant hand and were used for characterization of the injury pattern. The apparent pattern of injury was hyperextension and hyperabduction of the hand and digits. Common injuries were metacarpophalangeal and interphalangeal joint hyperextension with associated soft tissue avulsion, hyperabduction at the web spaces with associated palmar soft tissue tears, and finger disarticulation amputations worse at radial digits. Given the mechanisms of injury with tissue loss, surgical intervention generally involved tissue replacement rather than tissue repair. Blast injuries to the hand represent a broad spectrum of injuries that are associated with the magnitude of explosion and probably, the proximity to the hand. We were able to identify a repetitive pattern of injury and demonstrate the predominant use for delayed tissue replacement rather than microsurgical repair at the acute setting. Keywords: Blast hand injuries, Injury pattern, Hand reconstruction, Mutilating hand injuries, Explosives
Any guy would talk about this subject (civilian aspect of this, not military} with another guy and both would understand innately that this is mostly going to involve young guys and firecrackers. Here was part of the result: "...Of the 62 patients, 92% were male with an average of 27 years age (range 12–64). Most cases (89%) resulted in injury to the dominant hand...
We know, because almost all of us (seems to be mostly guys who do this) have done stupid, sometimes incredibly stupid things that could hurt us. It is sometimes a wonder any of us made it to the age of 20. It seems like every guy has a story, most turned out okay, but some didn't. And some guys have a bunch. (I tell my wife boy stories of adventure coupled with stupidity, and she only shakes her head. She never did anything approaching the harebrained things we did. I think sometimes she thinks I make it up, but guys out there know...everyone has a story.
Anyway, I digress. I don't think they are modifying the gas canisters to cause injury.
Just want to warn Freepers: if anyone does go to that link I provided, it is fascinating reading but it is a medical journal and has a couple of gory images near the bottom. Just warning. I used to work with a black woman who would page through some patient's chart, and when everyone had paper-based medical records, there would occasionally be photographs of surgery, injury, or anatomy physically glued into the chart, and she would be looking in detail for some physician note or blood test, turn the page and encounter a particularly gruesome or bloody image pasted in, and would abruptly close the chart while simultaneously exclaiming "Damn! Someone should put an effing warning on this chart!"
I found it hilarious, she was excellent at what she did, but she didn't want to see images like that!
Over time, I suspected she would do it because she thought my response to hers was funny...or she just wanted to make me laugh...either way, okay!