Shoulder Conditions

Why is the shoulder so prone to problems?

The shoulder complex is a complicated region of anatomy, requiring coordination of the multiple bones, joints, ligaments and muscles for optimal function. The shoulder joint proper is a very mobile ball and socket joint, which is protected by a system of ligaments that have traded-off some of their supportive/protective capacity to achieve mobility. Hence the rotator cuff group of muscles is incredibly important in adding stability to the joint, as well as coordinating movement of ball in socket while the lager, more external torque muscles produce movement and power. The scapular base that the shoulder sits on is in itself a dynamic structure that needs coordinated stability and placement by the muscles of the trunk, neck and chest, hence the common occurrence of related neck/spine/shoulder problems. The more complicated a mechanism, the more liable it is to problems. Not surprisingly the shoulder is very vulnerable to dysfunction, injury and pain-producing conditions. These problems may come about as the result of sporting trauma or overuse, as well as in the sedentary and occupational setting.

How is the shoulder injured in sport?

The shoulder is a fundamental tool-of-trade in all sports requiring throwing, swimming, tackling, falling, paddling etc. It can be injured by imposed forces, or by overuse and technique errors. Sudden forces imposed on the shoulder can lead to injury to the ligaments, with subsequent breach of joint stability producing subluxation or dislocation. The glenohumeral joint is susceptible to falls onto the out-stretched arm or awkward tackling manoeuvres, and the labrum (cartilage o-ring) may be damaged at the same time. The A/C joint (acromioclavicular joint) is often injured in body contact sports where there is impact to the point of the shoulder, e.g.. hip and shoulder bumps. Rotator cuff muscles can be torn by sudden trauma or forces, but this is usually in the older athlete. The humeral bone can be easily fractured by a direct impact force or fall.

What non-traumatic conditions affect the shoulder?

Apart from trauma, repeated use of the arm for throwing, swimming, paddling etc can lead to damage to components of the shoulder. The most common non-traumatic problem is subacromial impingement, which can lead to irritation of the bursa and rotator cuff muscles. Common diagnostic terms (some of which aren’t technically correct) include subacromial bursitis, rotator cuff tendonitis, supraspinatus tendonitis, rotator cuff tendinopathy. Why some athletes suffer these conditions and not others is usually a function of the athletes body make-up (their posture, coordination, conditioning, muscle length/strength/balance, joint stability etc). These are the issues that physiotherapist addresses. Training factors and overuse also play a part in producing this failure of shoulder components to tolerate sporting loads.

What shoulder conditions affect the non-sporting shoulder?

Second to low back pain, shoulder problems are rife in society. Because the shoulder complex is so reliant on peak biomechanical tuning to function optimally, any deterioration in posture, muscle and joint factors and patterns of use will impact heavily on the shoulder. The subacromial space could be considered the default ‘go-to’ site for impact of strain and injury when the shoulder is not working optimally. A combination of rounded shoulders, forward head posture, tense neck muscles, tight pectoral and lat muscles, chronic arm placement in front of body etc surmount to de-tune the shoulder. This de-tuned shoulder, then placed in a situation of occupational overuse or miss-use, becomes vulnerable to pathology including rotator cuff and bursal problems. These conditions have been listed above. The addition of age and chronicity to the equation can lead to more structural damage to the rotator cuff muscles including tears, as well as the A/C joint and shoulder joint proper. Frozen shoulder is another common condition. This condition is not fully understood, but it appears to be more common in women, diabetics, stroke victims, cardiac disease etc. the term “frozen shoulder” is used incorrectly for any shoulder that is painful and has limited movement. Idiopathic adhesive capsulitis is a distinct syndrome with unique identifying features.

What non-traumatic conditions affect the aged shoulder?

Common problems seen in the elderly are rotator cuff tears, subacromial impingement, frozen shoulders and less commonly, shoulder joint arthritis. Falls are also common in the elderly with subsequent fractures at the proximal end of the humeral bone. These can have a devastating effect.

How do we examine the shoulder?

Shoulder problems are always complicated and comprehensive examination processes are needed to examine the impact of bodily, sport and occupational factors. Posture is assessed to examine head and neck alignment, how the shoulder blade sits on the trunk, low back and pelvic posture. Large muscles connect the shoulder to the low back region, so these areas can’t be interpreted in isolation. Remember, you throw with your body, not just your arm. Spinal stability is very important to consider, as alterations in abdominal muscle tone and function will effect trunk alignment, thoracic posturing and coordinated movement of the shoulder. Cervical and thoracic spines are examined more specifically as they have potential to directly refer pain into the shoulder and arm, as well as their influence on posture and scapular positioning. Routine assessment includes range and quality of shoulder movement, muscle length tests, muscle strength tests, tests for ligaments/stability, test for labral injury, neurodynamic tests etc More refined assessment is required to ensure that the neck-scapular-thoracic muscles are functioning correctly to position and stabilise the scapular as the arm moves. The capsule of the joint is assessed for localised increases or decreases in flexibility, which if present can effect the positioning of ball in socket and lead to impingement or instability. Subscapularis muscle is thought to the deep stabiliser of the joint and critical to examine and treat in almost all shoulder problems. Radiology is of limited use in the non-traumatic shoulder. X-rays are necessary for suspected bone injury or to assess the form of the bone, eg. acromial beaking in subacromial impingement.

Ultrasound should be used sparingly as it is notorious for false positives (reporting features on film that aren’t significant) and false negatives (not reporting features that are present and significant, e.g.. rotator cuff tears). Despite this, they are use with frustrating frequency. MRI is useful for describing soft tissue injury inside the shoulder joint, e.g.. labral and capsular injury. CT demonstrates bone well. Bone scans are used to highlight ‘hot-spots’ where there is increased tracer update to metabolically active sites (where there is an active inflammatory or infective process). Assessment of the athletes technique and training schedule should be performed, but with respect given to their coach’s preferences and expertise in the area. Ongoing technique areas will undermine any medical advances treatment achieves. Assessment of the worker’s worksite and occupational demands is essential in the compensable market.

How do we treat the shoulder?

Treatment is a response to the diagnosis and findings on clinical examination. Subacromial problems (bursitis, rotator cuff irritation, tendinopathy etc) require attention to be paid to the patient’s biomechanics with a range of specific capsule and muscle stretches, posture and spine stabilisation correction exercises, deep muscle retraining, treatment to neck and spine issues etc. This programme would vary in intensity and specificity depending on whether you are talking about a young throwing athlete or a sedentary, middle-aged person. The subacromial space may be injected with local anesthetic and corticosteroid (usually under ultrasound control), which can be of benefit to reduce pain, but should never be a stand-alone procedure without attending to the underlying biomechanical cause of the problem. For severely recalcitrant problems where conservative treatment has failed, surgery may be considered to decompress the subacromial space, remove any anatomical obstructions to elevation of the humeral head (coracoacromial ligament, edge of acromium) and sometimes even resection of the outer end of the clavicle.

Post-operative rehabilitation requires exercise as described above to address the underlying biomechanical causes. Rotator cuff tears. Interestingly, rotator cuff tears are a very common finding in many people without shoulder pain, so care is needed with interpretation. If the tear is massive (wide and deep) and disables much of the rotator cuff, then surgery is needed to repair the muscle. Because of the demands and restrictions of the post-operative period, careful selection of patients should be undertaken. If the tear is small, there should always be an attempt to address the biomechanical problems that probably undermined the health of the muscle (see above), plus specific eccentric-overload exercises to promote renewed healing and strengthening of the muscle. These are very specific and potent exercises that need prescription and monitoring. Instability (looseness of the joint) leading to subluxation and dislocation is managed in various ways. For multidirectional instability of a non-traumatic nature, in someone born with general joint laxity, surgery is of no benefit. For a unidirectional instability as result of trauma, surgery may be required to fix the labral lesion and tighten the capsule, particularly if the athlete is to return to sport. Rehabilitation is required either to prevent surgery or in a post-operative phase. Correction of the deep stabilising muscle function is essential. Labral lesions require surgery to reattach or, if irreparable, to debride loose pieces. Labral lesions are often associated with instability problems.

Frozen shoulders are said to recover spontaneously, but you’d have to endure 18 or more months of pain, sleep restriction and stiffness in the hope that it would resolve. So more realistically, a range of pain managements such as steroid injections, plus exercises to stretch the joint and perhaps surgery to free the joint capsule is a more realistic action. The surgery may be a manipulation under anesthesia or capsule distention. Post-operative physiotherapy is needed to ensure the capsule doesn’t bind-down again. A/C joint injuries are common in contact sport, and while they are usually tolerable to play with once ‘rehabilitated’ even as a grade III (complete rupture), they usually give trouble later in life. The ligament doesn’t ever heal unless the tear grade is minor, so they do look “ugly” as the distal end of the clavicle sticks up in the air. Some footballing surgeons are providing primary surgical repair of severe tears, but the log-term benefit over conservative management is yet to be proven. Sternoclavicular problems are not common, but rate a mention because of the potential danger of a clavicle end that dislocates posteriorly into the vital structure of the neck/throat. This is a surgical emergency. They occur in body contact sports, eg. football where there is direct impact to the front of the clavicle. Shoulder joint arthritis is rare because unlike the hip and knee, the shoulder is a non-weight-bearing joint. If there is significant pain and disability as result of the arthritis, then a total shoulder replacement can be performed. Results of shoulder arthroplasty is a long way behind development of prostheses for the more commonly replaced joints such as hip and knee. You could expect a reduction in pain and minor if any improvement in function.