The backstory is that his mother, who's insane (I haven't figured it out exactly, schizophrenia or something similar, I think) pushed him with a great deal of force into some glass cabinets.
The cabinets probably had small things in there, most of which are likely breakable and/or pointed.
Would there be a likelyhood of scars forming from the injuries? The character in question is about twelve, male, with a very thin build (so he could easily go flying), and his mother is in her... early fourties, I think. Not a beefy woman, but deceptively strong, especially when having a "fit".
He didn't get proper medical attention for the wounds, just someone picking out the glass and maybe bandaging him. No stitches, I think.
Setting is modern day (a little in the future), Germany.
Search terms: "glass cabinet", "scarring", "scars"