A one year old baby can be judged simply by straightening the legs and looking at the gap between the knees and ankles. Looped legs are called “O-shaped legs”, which is medically known as inversion of the knee. It means that when the lower limbs are naturally straightened or standing, the heels of both feet can be contacted, and the two knees can not be close together, forming a gap similar to the letter “O”. Simple way to determine the baby to stretch lying down. Use both hands to gently straighten the baby’s legs, so that it to the center. Under normal circumstances, we let the baby’s legs together, its bilateral knee joints, bilateral ankle joints are close to each other. If the bilateral knee or ankle joints are not close together and the gap is greater than 10 centimeters, there is a greater likelihood of rotator cuff. If you suspect rotundity, take your baby to the doctor. Orthopedic orthopedic treatment should be performed along with treatment of the primary disease such as vitamin D deficiency rickets.