Two feet together with a gap between the calves is commonly known as O-shaped legs, medically known as knee inversion, can be caused by a variety of reasons, such as heredity, meniscus injury, osteoarthropathy and so on.
Knee inversion manifests itself as a natural straightening of the lower limbs or when standing upright, the two heels can touch each other, the two knees can not be close together, and there is a gap between the calves. Physiological inversion of the knee is common, mostly in children, after birth with O-shaped legs as the main manifestation, until about 2 years old, the children’s lower limbs will gradually become straight, at about 6 to 7 years old close to adults.
If vitamin D deficiency causes abnormal calcium and phosphorus metabolism during growth, it can cause rickets, which is the most common cause of pathologic knee inversion.
Adults with medial meniscus injuries or the elderly with osteoarthritis of the knee can also develop pathologic knee inversion, which should be promptly consulted.