The scapular is the medical term used to describe the shoulder blade. The scapular is a flat bone which sits on the upper thorax. Due to the fact that it does not have any significant bony connections it is termed a “floating bone”. It is instead held in position and moved by groups of muscles.
Scapular winging refers to when the inside edge of the scapular is not held tight to the upper thorax wall. It can refer to the scapular position at rest or during movement. Both normally occur to a certain extent. The type and extent of scapular winging is often determined by the cause of which there are many.
Normal variant of posture
Although scapular winging may be a contributory factor in shoulder weakness and or pain, normal scapular position is highly variable among individuals. Individuals with a straighter posture to their thorax often includes individuals at the upper end of the flexibility scale (hypermobility syndrome). In these individuals a “winged” scapular appearance may be entirely normal and may only be addressed if pain and weakness begin to manifest.
Spinal & muscle stiffness
The pectoralis minor and long head of biceps tendons attach themselves to a projection of the scapular at the front of the shoulder (coracoid process). Due to these attachments, when very tight or overactive they may contribute to tilting the scapular forwards and into a winged position. This form of winging is not identical to other forms of scapular winging and is often termed pseudo winging.
Serratus anterior muscle weakness
The serratus anterior muscle attaches the inside edge of the scapular to the sides of the ribs. In this way, when contracted or “active” it pulls the inside edge of the scapular towards the thorax, thereby, reducing any winging. Sub optimal serratus anterior strength may be as a result of prolonged spinal and shoulder postural adaptations from occupational positions, poor training technique when exercising or existing shoulder pain.
Long thoracic nerve palsy
The main muscle which maintains the scapular position and prevents scapular winging is the serratus anterior. This muscle is innervated by the long thoracic nerve which runs from the side of the neck down and underneath the scapular. In rare circumstances, the long thoracic nerve may be injured, as such causing severe weakness to the serratus anterior muscle. Although long thoracic nerve injury may occur due to trauma, the most common cause of injury results from an inflammatory reaction to the nerve. This is termed a neuritis and the exact cause is unknown but may result post virus, post general anaesthesia.
The treatment of scapular winging does not have a solution other than corrective physiotherapy programs. However, the exact physiotherapy program administered or prescribed may be dependent on the cause listed above.
If the scapular winging is secondary to stiff pectoral muscles then a corrective program may involve hands on manual techniques to release the pectoralis minor tightness as well as a home exercise program to stretch the muscle. Often mobilisation techniques and exercises designed to reduce stiffness through the torso can also help to relieve the stiffness through the front of the chest.
The mainstay of treating scapular winging will often involve optimising the activity or strength of the serratus anterior muscle. In situations where there is a simple strength deficit exercises may involve push up variations or reaching or punching exercises which load the muscle preferentially. The serratus anterior muscle is in fact often referred to as the “punching muscle”.
In situations where the serratus anterior muscle is denervated the exercises will be commenced at a lower level. Physical rehabilitation may commence with exercises which hold positions (static contractions) or commence certain movements against bodyweight or in positions which eliminate gravity. Good example may be press ups against a wall in standing rather than more difficult progressions in to full press up positions.
The fact that scapular winging is not a progressive problem and does not need any invasive treatment means that the prognosis for scapular winging is very good. With an appropriate physiotherapy program the vast majority of cases will be able to return to full activities of daily living or sporting function without significant pain.
In cases where there is significant long thoracic nerve palsy the prognosis will depend to a large extent on the ability of the nerve to regenerate. The main factors which influence this include the severity of the denervation (partial or full) which may be assessed with nerve conduction studies and why the denervation occurred, either trauma or neuritis.
Other factors which influence the healing of neural tissue involve patient specific factors. These include general health of the patient, age of the patient, whether the patient has significant other injuries which are also in need of treatment. In general, in cases of significant long thoracic nerve denervation, clinicians may recommend an individual gives the problem up to two years before any improvements begin to plateau.