Kids with ADHD get injured a lot! Usually it happens because they act before they think - and, of course, they are always on the go. So you might want to check out that possibility. I have listed some of the symptoms from the medhelp site. You can always check out the ADHD forum for more answers.
Inattention symptoms:
1. Fails to give close attention to details or makes careless mistakes in schoolwork
2. Difficulty sustaining attention in tasks or play
3. Does not seem to listen when spoken to directly
4. Does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace
5. Difficulty organizing tasks and activities
6. Avoids or dislikes tasks that require sustained mental effort (such as schoolwork)
7. Often loses toys, assignments, pencils, books, or tools needed for tasks or activities
8. Easily distracted
9. Often forgetful in daily activities
Hyperactivity symptoms:
1. Fidgets with hands or feet or squirms in seat
2. Leaves seat when remaining seated is expected
3. Runs about or climbs in inappropriate situations
4. Difficulty playing quietly
5. Often "on the go," acts as if "driven by a motor," talks excessively
Impulsivity symptoms:
1. Blurts out answers before questions have been completed
2. Difficulty awaiting turn
3. Interrupts or intrudes on others (butts into conversations or games
From:
http://www.medhelp.org/medical-information/show/2157/Attention-deficit-hyperactivity-disorder-ADHD?page=1#sec_3761