ARE MY LEOPARD GECKOS SICK?

I have 3 Leo s and 1 is very healthy and energetic but the other 2 Leo s that are younger are always lazy this may seem like a dumb question but get this ! When they move around they don t really use their arms the like drag them across the tank it look almost like if their legs were asleep and don t have any energy to move and another thing they both have some sort of bubble in there arm pit area of their upper arms I don t know if that s the case but when they both eat they always miss what they are trying to catch they are not to skinny and not to far they are slim take a look at the photo do u have answers