Anatomy
Der er 4 muskler i muskelskeden (rotatormanchetten) omkring skulderleddet, som styrer, koordinerer og assisterer bevægelsen i skulderen: M supraspinatus (øvre skulderbladsmuskel), M infraspinatus (nedre skulderbladsmuskel), M subscapularis og M teres minor. Når armen føres ud fra kroppen og op over hovedet (abduceres), glider supraspinatus-musklen ind under det øverste skulderbladsfremspring (acromion).
The shoulder blade muscle seen from behind:
A. Acromion
B. Tuberc. majus (humeri)
C. M. infraspinatus
D. Spina scapulae
E. M. supraspinatus
Cause
With repeated loads with the arm above the head (tennis, swimming, throwing), the upper shoulder blade muscle tendon (M supraspinatus) becomes ‘inflamed’ (inflamed), swells and, together with the bursa above the tendon (bursa subacromiale), can become pinched (impingement) between the head of the humerus (caput humeri) and the upper bone projection of the shoulder blade (acromion).
This weakens the tendon with a risk of rupture. Not infrequently, tendonitis is combined with mucosal inflammation.
Symptoms
Slow onset of localised soreness after strain on the outside and front of the shoulder. Occasionally radiating to the upper arm. The pain worsens when you press on the supraspinatus tendon at the front of the shoulder and when the muscle is activated (the arm is lifted out to the side) and relaxed (the hand is brought to the lower back).
Examination
The diagnosis is usually made through a general clinical examination where there is pain when lifting the arm, possibly against resistance. For more severe pain or difficulty lifting the arm away from the body and lack of progress, a professional examination should be performed to ensure correct diagnosis and treatment.
General clinical medical examination is often sufficient to make the diagnosis. If there is uncertainty about the diagnosis, an ultrasound scan (or MRI scan) should be performed (Griffith KM, et al. 2022). In some cases, calcifications in the muscle tendon are detected, which can complicate rehabilitation (Merolla G, et al. 2015).
Treatment
Treatment primarily involves relief from the pain-inducing activities, stretching and rehabilitation of the muscles around the shoulder within the pain threshold. If rehabilitation is not successful, medical treatment may be considered in the form of arthritis pills, NSAIDs or injection of adrenal cortical hormone (usually in the subacromial bursae above the supraspinatus muscle).
As adrenal cortex hormone injection is part of long-term rehabilitation of a long-term injury, it is often necessary to extend the rehabilitation programme over several weeks to months to reduce the risk of recurrence and rupture. Of course, after a long-term injury, the tendon cannot withstand maximum strain after only a short-term rehabilitation period.
If there are calcium deposits in the shoulder muscle, you can try to suction them out while injecting adrenal cortex hormone around the calcium deposits. If rehabilitation and medical treatment are unsuccessful, surgical treatment can be attempted.
Complications
If the progress is not smooth, you should consider whether the diagnosis is correct or if there are complications.
In particular, the following should be considered:
