Injuries from practice?
Injuries of any fall, practice, and various unnatural positions will happen, but with insight, careful practice, and teachers who have seen many of the mistakes taught by overzealous practitioners of a Martial Art, they will take proper precautions to lesson injuries.
Maybe it is from a lifetime of injuries in various degree's that haven't included major bone breaks, just minor ones, that I tend to slow down many of the techniques until rythm and motion are almost a second nature when performed at full speed.
Of course, it could be from finding new meanings in Kata done in slow motion that allowed me to understand the physical dangers of many of the simple moves we take for granted in Martial Arts, Aikido included.
I like to remember the tooth pick.
We can use it to pick our teeth in a restaurant, but in a tornado it can be driven through the trunk of a tree? Chance, or predestiny?
I don't leave toothpicks out, anymore.