How can i prevent toenail injury and bruises under my toenails when dancing ballet?

Trim nails: But be careful. The most common cause of ingrown toenails is trimming them too short along the edges and this problem can be a lot more painful then simple bruising. Try trimming the nails short but keep them "square" at the corners with gentle filing. This will help prevent trauma and subsequent bruising of the bed of the nail.

Nail bruising: This happens commonly in dancers and in particular ballerinas. Unfortunately it is difficult to avoid this entirely, especially in the dancer who is en pointe a great deal of the time. To lessen the chances of this occurring ensure your pointe shoes are well padded in the toe box (you can supplement this with gel caps for the toes) and that the nails are trimmed short and regularly.