Humeral joint instability is often a diagnosed disease of the movement system. If left untreated, it can lead to serious disorders in shoulder mechanics and other health consequences seemingly unrelated to the shoulder girth. Learn more from the article.
What is shoulder instability?
Shoulder instability is understood as the inability to keep the head of the humerus in the glenoid cavity during movement. Under normal conditions, the balance of structures within the humerus is responsible for the quality of the movement performed. At any point in movement, the tension corresponding to the phase of the muscle and ligament group is activated and transmitted, which happens in fractions of seconds and ensures the full range of motion, its fluidity and painlessness. The problem occurs when one of the structures functions incorrectly for a long time or is damaged. Then there is a disorder of the complicated mechanism of movement in the joint, and instability can be one of the consequences of such a condition.
Anatomical changes cause humeral Joint instability
The cause of shoulder instability can lie in chronic or acute injuries. Functional instability occurs as a result of chronic abnormal tension within the humerus, which can be caused by:
- abnormal body posture (e.g. deep pectoral kyphosis and head and shoulder protraction),
- laxity of the muscle of the shoulder girdle,
- hypermobility of joints (congenital or acquired, e.g. by practicing artistic gymnastics or swimming),
- regular overload and microtraumas within the joint (e.g. as a result of physical work, overhead work or competitive sport).
Most often, the formation of post-traumatic shoulder instability occurs as a result of:
- dislocation of the humerus
- damage to the glenoid labrum (e.g. Bankart lesion)
- damage to the humerus (e.g. Hill-Sachs lesion)
The static stabilisation of the arm is based on ligament, bone and cartilaginous structures. These include a joint capsule reinforced by the coracohumeral ligament and the glenohumeral ligaments (upper, middle, lower). Glenoid labrum and the tension in the joint itself also play a very important role. The disorder of one or more of the above-mentioned structures can result in instability and progress over time.
Disorders in the stability of the head of the humerus relative to the shoulder may manifest itself more or less clearly – depending on the severity of the injury. Despite the characteristic symptoms, it is often difficult to quickly and correctly diagnose the condition of the humerus. Due to the very many pathologies that can cause disorders in this region, diagnostics can be quite a challenge.
Shoulder instability is mainly manifested through:
- spilled pain throughout the shoulder,
- audible “clicking”, “jumping” in the joint,
- problems with arm lifting above the head, smooth visitation,
- in sports requiring throwing – intense pain during physical activity.
Depending on the course of the disease, symptoms of ‘trapping’ of the supraspinatus muscle may also occur, – thus the mobility of the arm, especially its visit, will be limited. Often, however, instability is associated with hypermobility of the joint, which can be accompanied by damage to the articular vein and laxity of the joint capsule at the same time of the high strength of the shoulder girdle muscles (e.g. in swimmers). For these reasons, the condition can be somewhat surprising in its course and for two patients with a similar problem, it can differ significantly in the clinical manifestation of the problem.
Instability of the humeral Joint – diagnosis and treatment
Diagnosis of the problem should be based on imaging and functional tests, designed to assess the condition of tissues and the degree of their damage, if any. The basic information will be provided by an X-ray and ultrasound, thanks to which it is possible to effectively assess the position of the humerus relative to the shoulder blade and clavicle, as well as the condition of the soft tissues surrounding the joint. Functional tests useful for joint instability include provocative tests (e.g. Jerk Test), which are easy and quick to perform.
Treatment is mainly based on conservative methods. In case of pronounced damage within the shoulder girth – surgical intervention is necessary. However, functional instability occurs more often, which is why different methods of rehabilitation make great sense here. These include:
- Manual therapy:
- Soft tissue relaxation techniques (fascism therapy, tool therapy, positional relaxation)
- Dry needling
- Joint mobilisations and manipulations (if the range of mobility is limited)
- Kinesiotherapy:
- Shoulder rim and shoulder girdle reinforcement excercise
- Proproception excercises (e.g. PNF method) on Automobilisation
- Physical therapy (high energy laser therapy or Tecar can be used to help with joint regeneration)
Kinesiotaping is also helpful, which improves the deep feeling of joints and helps to acquire.
Treatment of instability of the humerus is a long-term process, requires patience and commitment of the therapist and patient. With well-chosen methods of physiotherapy or surgical treatment, the effectiveness is very high. It should be remembered that untreated instability of the humerus can lead to a habitual dislocation of the shoulder, the therapy of which is much more challenging. If you have such a problem it is best to consult him with a specialist.
