Spraddle leg, also referred to as splay leg, is a condition where a chick’s legs “splay” out to the sides. Sometimes one leg is affected and other times both are. Often it occurs from brooding chicks on a slippery surface such as newspaper, but other causes include incubator temperature issues (if a large number of chicks are affected at hatch, this is most likely the cause), vitamin deficiency, or being in a poor position in the egg. All poultry are at risk for spraddle leg.
If you search for solutions to spraddle leg on poultry forums, you will see suggestions for securing the legs in place using bandaids, medical tape, or string. The Chicken Chick likes to use VetRap for easy application and removal. The idea is to allow the legs to strengthen in the proper position. Although these methods can work, I find using a simple drinking glass to be both easier and faster.