The supraspinatus (Latin supraspinatus) resembles a triangle that lies at the supraspinatus of the scapula, reflecting its shape. It runs from the paraspinal end of this fossa to the proximal end of the humerus, where there is the attachment, which is the sharpest angle of this somewhat elongated "triangle". Pain in the supraspinatus muscle is most often associated with incorrect body posture, bad posture at work and incorrect training technique.

The supraspinatus is a delicate structure that is susceptible to injury. Bad technique or too high intensity with which disciplines are performed that require shoulder work with great force or frequency (e.g. athletics, tennis, swimming, shot put, javelin, hammer or golf) are especially predisposed to overload it. But the same effect can be achieved by working while sitting or regularly adopting incorrect posture.

Supraspinatus - structure

The supraspinatus musclebegins at the supraspinatal fossa of the scapulaandon the supraspinatal fascia . Its fibers converge towards the distal attachment, which is on the upper surfaceof the greater tubercle of the humerus , to which it is attached with a strong and short tendon. This tendon also connects to the articular capsule of the shoulder joint.

From the side of the spine, it is covered by the trapezius muscle. To the side it runs under the shoulder-clavicular joint and the corpus-brachial ligament, and at the very attachment it lies under the deltoideus muscle (Latin deltoideus). The supraspinatus muscle covers not only the surface of the supraspinatus, but also the nerve and suprascapular vessels that run there. The whole structure forms a bone-fibrous chamber, which includes the supraspinatus. It is "wrapped" in a fascia, from which only the flat supraspinatus tendon emerges.

The innervation of the supraspinatus is caused bysuprascapular nerve(C5-C6). Damage or compression of this nerve causes characteristic symptoms, which include:

  • pain in the scapula when making movements with the upper limb;
  • limitation of mobility in the shoulder joint;
  • resting shoulder pains.

In bloodsupraspinatus is supplied byarteries: suprascapular, subclavian and surrounding the axillary scapula .

Supraspinatus - Functions

The supraspinatus works together with the deltoid muscle, working together with itabducting the arm . In doing this,tightensalsoshoulder joint bag ,turns the arm outward and bends it slightly .

If the deltoid muscle is paralyzed or damaged, the supraspinatus takes over the function of shoulder abduction. However, this movement takes place to a lesser extent, because the supraspinatus muscle is too weak in relation to the weight of the entire limb to operate freely.

The supraspinatus muscle also forms an important and often problematic structure calledrotator cuff. It is responsible forlifting the armandperforming rotational movements in the joint .

Jobe's test

To assess whether the supraspinatus is functioning properly, the Jobe test is performed. The patient positions his arms in abduction up to 90 degrees and in flexion (preferably so that the angle formed by both upper limbs with their proximal ends is also 90 degrees). Both arms should also be turned inwards.

The physiotherapist exerts pressure from above on the arms in this position while the patient tries to resist. The test is positive when it provokes pain. Pain sensations may accompany him earlier, while taking the position, before the physiotherapist applies force. The inability to painlessly assume or maintain this position also indicates a dysfunction of the supraspinatus.

Pain in the supraspinatus

The supraspinatus is often a source of pain and restriction of mobility in the upper limb, although it is not always correctly diagnosed - especially when it is chronic pain. Long-term increased tension of the supraspinatus may result in pain not only of this muscle, but also of pain radiating to the entire arm, to the elbow, and even to the wrist. The sources of such symptoms are often first sought closer to the pain site or the spine, and not around the shoulder girdle.

Prolonged pain may lead to a gradual limitation of mobility, and eventually the discontinuation of the use of the upper limb. Serious complications are also possible, includingentrapment syndromeorfrozen shoulder .

Malfunctioning supraspinatus can alsocause unusual pain that seems to come from your other joints. Therefore, it is also worth testing in patients who report symptoms oftennis elboworde Quervain's disease , as it may be associated with them. Improper functioning of the supraspinatus can also be the cause ofsubacial bursitisand inflammatory changes orcalcificationwithinrotator cuff .

Supraspinatus - causes of dysfunction

The small size and strength of the supraspinatus, which is attached to a very mobile and often heavily loaded limb, makes it easy to overload it. Therefore, the main reasons for its dysfunction are of a mechanical nature:

  • posture defects (hunched body, protraction of shoulders and neck),
  • weakened back and abdominal muscles ,
  • performing work related tolong-term lifting of handsover the head,
  • sedentary lifestyle(especially with hands extended to the mouse or keyboard),
  • carrying heavy objects ;
  • bad sports technique , especially in disciplines that require high-frequency shoulder movements (tennis, swimming, shot put, javelin, hammer, and golf)

Supraspinatus damage may also be caused bysubacromial bursitisand the associatedsubacromial tightness syndrome . It limits the blood supply, which contributes to the weakening of the tendon structures and may lead to the tendon rupture of the supraspinatus muscle.

Among the less common causes of supraspinatus dysfunction are disturbances in the functioning of internal organs: the pancreas, liver, stomach or lungs, which may manifest as pain projected onto the shoulder girdle.

Supraspinatus - treatment

After proper diagnosis, manual therapy and deep massage usually turn out to be the most effective in the treatment of supraspinatus. Supportively, physical therapy and dry needling are also used. The most important thing, however, is that the therapist assesses the supraspinatus in the context of adjacent structures and the patient's entire body to make sure that the source of the problem is precisely that structure.

In order to prevent injuries and overload of the supraspinatus, it is worth doing exercises that will strengthen it. Its main function is abduction in the shoulder joint, so this muscle strengthens together with the deltoid muscle by abducting with a load (weights, rehabilitation tapes, etc.).

Bibliography

  • Bochenek A., Reicher M., "Human Anatomy", volume I, PZWL Medical Publishing, Warsaw 2012.
  • Buckup K., Buckup J., Clinical tests in the examination of bones, joints and muscles, Wydawnictwo Lekarskie PZWL, Warsaw 2014.
  • Wiszomirska I., Anatomy of the human locomotor system, AlmaMer Publishing House, Warsaw 2009.

Category:

Anatomy