When I was a kid I played street hockey (inline skates) daily. Had quite a few spills but nothing serious. The biggest injury is a broken wrist when you put out your hands in front of you to cushion a fall. They have pads and braces to prevent that injury, if you take the kids there a lot id say maye invest in the wrist guards.

Here's a link...there are a lot of these out there, just an example:
http://www.google.com/products/catalog?hl=en&gs_sm=3&gs_upl=7319l10327l0l10479l6l6l0l0l0l0l105l498l5.1l6l0&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&biw=1920&bih=945&q=fall+wrist+protector&um=1&ie=UTF-8&tbm=shop&cid=13625415838681329625&sa=X&ei=kC5BT7u9DIHb0QHT-53rBw&ved=0CIsBEPMCMAA

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth