what kind of light are you using and how far is it from your babies.. they appear to be stretching for the light, which would mean that your light source is a lil too far away..
you can do one of several things to help them along.. you can cut a piece of straw to the size of your stems, slice it length ways, and put it around your stem to help hold em up.. or you can repot them and just bury them up till the first set of leaves.. this is what i like to do.. or you could just add some more soil to the top of your pots if you have the room just do the same, bury your plants up till the first set of leaves..
edit.. i didn't even look at your pix, sorry,, what are you using, rockwool it looks like? you could do the same with the straw, or could use some hydroton rocks to help support them instead of the soil..
sorry, should have looked first, my bad...
Bring the light closer to the plants for a few days & see if it helps. I agree with Racerboy that the light appears to be the problem & your plants are "stretching" for it.