Poorly wing

Hi, one of my chickens seems to have hurt her wing this morning. I don't think it's broken, she didn't mind me touching it too much to have a look. She seems a bit subdued and has been spending all her time in the coop this morning (not sure if this is due to the hot weather and thousands of thunder bugs though)
I've put some pictures of her and her wing, if anyone has any ideas what could be wrong or if I need to do anything for her!

If she's injured it she could be in pain.  The hen uses a muscle to hold the wing to her side. If she's hurt herself she might find it painful so the wing hangs down as the effort needed to keep it tucked in could be too painful.  It could well right itself within a few days but if the hen is walking wobbly or rolls over then it needs attention. Mine had a painkilling anti-inflam injection and was immediately 100% happier and the wing healed within the week. 

Oh that's good news