This has nothing to do with candling. And it can be any of several causes, none of which you are likley to know for sure.
One of the reasons they say to hatch medium sized eggs instead of really large eggs is so you don't get really large chicks, who end up too heavy for their own legs to hold them up. Are these two monster, fatso chicks? If so, they may yet get themselves together and learn to walk.
I keep a bottle of cod liver oil capsules on hand for chicks born weak or with ligament/joint problems. If the defect is from poor nutrition during development, a dose of cod liver oil right away can sometimes help. Sometimes.
If the chick has 'yolk belly', the enlarged or off centered gut can push out against the legs, making proper movement difficult. If these two managed to hatch on their own,I tend to think this problem can be overcome. If they are screaming and squawking worse than anyone else, there might be a bigger problem. If they are sleepy, dopey and not alert like everyone else, there might be a bigger problem. But if they seem normal in all ways except for their legs, then give them a few drops of cod liver oil and wait and see. Also DO NOT force fatso chicks to eat and drink right awa after hatch. If a diet is what they need, they are good for a day and a half at least without food or water. Also be sure no to overheat them, as that causes chicks to melt and lay around like blobs too, panting and miserable.
Give them a couple days to see if they can work it out. Cull if you think they are showing signs of other misery like loud peeping or excessive sleepiness.