Healing spells in HP

[Charmian]

No: HPFGUIDX 7332


<Weird/silly question alert>

It seems like the HP characters are constantly going to the 
infirmirary in the books, mostly for magical injuries. But how easy 
is it in the system Rowling has set up for wizards to heal non-magic 
injuries? Can they just do a quick spell and take care of a scrape? 
As I recall, Lockheart attempted to take care of Harry's broken arm, 
and it seemed to imply that he should have been able to do it. Wonder 
why Harry and co. haven't learned those spells yet, as they seem 
quite useful. 

Charmian