Symptoms
The symptoms of an existing scapula alata depend on its extent and also the cause. A visible sign is the wing-like protruding shoulder blade, which protrudes from the body to varying degrees depending on the cause. In the case of paralysis of the serratus muscle, in addition to the malposition of the shoulder blade, a reduction in strength and weakness in lifting in the same arm also occurs.
This leads to further restrictions in everyday life and in some sports. Some patients also report a feeling of pressure in the shoulder area. In general, the scapula alata shows no symptoms in most cases (asymptomatic).
However, since it is a malposition in the skeletal system, this can lead to further problems in the muscles such as poor posture and tension. Pain may well occur with an existing scapula alata, but does not usually occur frequently. Pain can occur if the scapula alata is very pronounced and the chest as a whole becomes malpositioned.
In some patients, this can also reduce the mobility of the upper body. This can also lead to further postural damage. In addition, pain occurs particularly in the context of nerve injuries to the long thoracic nerve, which can be caused by accidents or overloading. If certain nerves become entrapped because the thorax is malpositioned, there may also be signs of loss in the arm and hand.
Why does the scapula alata occur predominantly unilaterally?
The classic scapula alata occurs mainly unilaterally, as it is often based on the failure of a specific nerve.This is the thoracic longus nerve, a nerve that supplies the anterior serratus muscle. This muscle is responsible for lifting the shoulder when the arms are raised forward. The nerve and muscle occur on both sides, left and right.
Theoretically, both nerves can be damaged at the same time and cause a bilateral scapula alata. However, unilateral nerve damage is more likely and more frequent, resulting in muscle paralysis. Possible causes of paralysis of this muscle are mechanical stress on the thoracic nerve longus, for example, permanent carrying of heavy objects on the affected shoulder, such as a handbag.
