Swollen hamster leg

[Snowy17]

Hi. This is my first time posting on here so not really sure where I'm meant to put this. Basically I have a 2 year old Syrian hamster called Snowy. When I woke up yesterday she had her leg stuck between the bars in the corner of her cage. I managed to free her leg and she is managing to walk on it. My only concern is that it has swelled and is quite red. She keeps trying to climb up the cage but falls as I don't think she can grip with her paw. Not really sure what I can do to help her. My worry is that she is in pain but I don't know. Does anyone have any suggestions?