You can use the information from here:
"Why are children with upper limb abnormalities twice as likely to have posture disorders and how to avoid it?
Doctors identify two main mechanisms for the development of abnormalities in our children. The first is the unequal weight load on both sides of the body. Simply put, one side of the limb is longer than the other, which means that one side of the body weighs more. Accordingly, the higher the amputation, the greater the difference in weight and the risk of developing postural abnormalities. (1,2)
The second mechanism is unequal functional load. If we translate the medical term in simple language, it means that one hand is more active in our everyday and professional activities - we use it to pick up, move, transfer, etc. In the best case, the child tries to involve the "special" hand in various tasks, for example, presses objects to the body with it. But this limb cannot fully take the weight of these objects, and the range of activities for it is still much smaller.
How to suspect posture disorders and when to see a doctor?
There are several signs of bad posture. As a parent without an in-depth knowledge of anatomy, the easiest thing to notice is that one shoulder is lower/higher than the other, the shoulder blades are at different levels, or the spine is deformed and the child is not standing straight. If you notice any of the above in your child, you need to see an orthopedic trauma surgeon. For further diagnosis the doctor should examine the child and if there is a suspicion of scoliosis (deformation not at the muscle level but at the level of the spine) refer him/her for X-ray examination.
A long post could be written about the treatment of posture disorders, because it is usually not easy and takes quite a long time. Therefore, it is very important not to treat, but to prevent such changes.
To do this, you need to:
1) visit an orthopedic traumatologist every 6-9 months for preventive examinations
2) do every day a set of 5-7 exercises for back muscles and abs (if you do not know what exercises, write under the post, we will tell you).
3) WEAR A PROSTHESIS!!!! It is the active prosthesis that affects both mechanisms of posture disorders - adding both missing weight and grip function to one side of the body.
4) Assistive methods can also include massage and swimming."
"Most of our CYBI heroes are able to cope confidently with various types of children's transport even without a prosthesis, but the load on the arms and body is distributed extremely unevenly during such a ride. The naked eye can detect this by looking at the child's posture while riding - most likely he is sitting unevenly and his spine has a pronounced curvature.
Bicycling and scooting are good examples of activities that can be done with or without a prosthesis. We all understand that there is no irreparable damage to your health from a 40-minute bike ride without a prosthesis. But it must be understood that the total aggregate of such "comfortable and without a prosthesis" activities is quite a lot. While the curved position of the spine is quite obvious when using a bicycle, at other times it may not be visible to the eye, but it is extremely noticeable to the muscles. It is the muscles that are responsible for gradually getting used to the incorrect position of the body, and it is the muscles that then prevent the spine from taking the correct position.
In addition, the constant loading of a healthy arm overloads its joints, ligaments, and muscles. It takes a long time for the overload to become noticeable. As a rule, painful sensations appear in adulthood and cause great discomfort, because they can disable the only healthy upper extremity. This secondary impairment is called healthy limb overload syndrome and occurs in 50 percent of cases of unilateral arm absence. (3)