why do all the child objects become deformed when i import them from blender to unity?

hello, I have a problem. I made a game object in blender, and when I animated it I didn't want to have to animate all of the little parts of the legs, so I parented the little parts of the legs to the big parts so that I only had to animate the big parts of the leg and the little parts would follow the big parts, just like they are one object. this worked fine in blender however when I imported it to unity it stretched and deformed the child objects. does anyone know how to fix this? please help!

here is a picture of the object before I imported them from blender to unity:

here is a picture of the object when I imported it to unity:

as you can see in unity the legs stretch.