What are the X and O legs? X legs and bow legs are terms for the leg position in young children. X legs, also called genoa valga, have the knees closer together than the feet. Viewed from the front the legs are in the shape of an ‘X’. In the case of bow-legs, also called genoa vara, the knees are further apart than the feet. Seen from the front, the legs are in the shape of an ‘O’. During development it is normal for every child to have bow-legs and X-legs successively, with some it is more pronounced than with others. Only rarely is something going on. Let’s see more about X and O legs.
Symptoms of the X and O legs
Every baby has bow legs. In the course of the first two years of life, this becomes less and less. On their second birthday, most children have straight legs. After this the knees get closer and closer together. The child slowly but surely develops X-legs. When the child is about three years old, the X legs are maximum. Then they slowly decrease and by the seventh birthday the legs are almost straight again. And it remains that way from this age.
Not every child’s X and B legs are equally clear. For some it will hardly be noticed, while for others it will immediately catch the eye. In both cases it is normal. Children with pronounced X or O legs can suffer from it. They walk awkwardly and can trip over their own legs, especially when they run.
How do X and O legs arise?
With X-legs and O-legs, the bones of the lower and upper leg are on top of each other in such a way that they form an X or O. With bow legs, there is often also a slight bending and rotation of the bones. It is almost always a normal development. In rare cases, there are certain abnormalities such as rickets (“English disease”) or hormonal growth disturbances.
How to identify your leg shape?
Under normal circumstances, the knee joint can only perform flexion and extension exercises. In the case of a large knee bend, a small rotation can be performed.
In a normal leg shape, the femur and tibia are not aligned, but form an angle of 5°-10°, which is called physiological valgus. Due to the existence of this angle, more powerful force is required on the inside of the knee joint to maintain stability.
Therefore, the medial collateral ligament of the knee is much stronger than the lateral collateral ligament.
If due to long-term improper load, the tissues that maintain joint stability are unbalanced or even become loose, it may cause abnormal joint alignment.
The most common are varus and valgus of the knee joint.
Knee varus refers to the inner side of the femur and tibia being close and the outer side away. Eversion is the opposite, close to the outside and away from the inside.
–Knee valgus X-leg case
In this case, we can see that the distance between the knee joints is much smaller than the distance between the feet.
–Knee varus O leg case
In this case, the feet are close together, but there is almost a punch between the knee joints.
In addition to varus and valgus, the knee joint may also rotate, that is, the femur and tibia are twisted relative to each other, which makes the situation more complicated.
Under normal circumstances, the patella and the second toe are facing forward, which ensures that the joint movement and the forward direction are consistent when we walk. However, this consistency also requires a lot of coordination between muscles and soft tissues.
Rotation related to leg shape can generally be divided into two categories.
The first type is internal rotation of the hip joint.
The hip joint is composed of the femur and hip bone. When the front and medial tissues of the hip joint are tense, and the back and lateral tissues are weak, internal rotation of the hip may occur.
Under normal circumstances, the physiological valgus of the knee joint reduces the distance between the knee joints on both sides. When the femur appears internal rotation, the distance of the knee joint will increase, resulting in an O-leg with internal rotation of the hip.
If the knee joint is in an over-extension position at the same time, the O-shaped leg will be more visible visually.
Knee hyperextension, hip internal rotation, and pelvic anterior tilt often occurs at the same time, and actually involve abnormal alignment of the lower limbs in multiple directions.
Calf valgus is actually the internal rotation of the hip joint, causing the calf to move outward.
The second category is the relative rotation between the foot, tibia and femur.
Take a closer look at the leg type case in the picture below. Can you figure out what’s going on?
This type of leg is not uncommon, which is often referred to as the XO leg.
The knees and heels on both sides are close together, but there is a clear space between the thighs and the calves.
In fact, this leg type includes knee valgus and tibia twist.
- Knee valgus
We can see the obvious bulge (medial femoral condyle) from the inner side of the distal thigh of the student in the case, indicating that the knee joint is valgus, the inner distance is enlarged, and the hip joint is in an adduction position.
- Tibia Torsion
In this case, the student’s patella is facing forward, but the second toe is facing anterolaterally. If we look closely, we can see that her tibial tuberosity is also facing the anterolateral side, indicating that the tibia rotates outward relative to the femur.
After the above analysis, everyone should have a basic understanding of how to analyze leg shapes. May wish to use this method to judge your leg shape.
X and O legs serious and what can you expect?
In childhood bow legs and later X legs are completely normal. It is part of normal development. In a very small proportion of cases, the bow legs and the X legs remain longer. If the spontaneous correction does not occur, these children can be treated by a podiatrist or operated by an orthopedic surgeon.
When to go to the doctor?
It is wise to make an appointment with the doctor if:
- your child still has bow legs after the second year;
- your child still has X-legs after the seventh year;
- your child only has an X or O leg on one side;
- your child’s X or O legs are not symmetrical;
- your child develops bow legs after his second birthday;
- your child gets X legs after his seventh birthday.
In those cases too, it is rarely necessary to intervene. Given the growth of the child, it is still possible to intervene until puberty. If treatment or surgery is being considered, it is important to consult the podiatrist or orthopedic surgeon before puberty.
What can you do about it yourself?
You cannot and do not have to do anything about your X or O legs.
General advice and precautions for X and O legs
X and O legs are usually part of normal development and cannot be prevented.
Share “X and O legs” with others.