Rotator cuff tendonitis or tendinopathy is a degenerative condition affecting one or more of the rotator cuff tendons in the shoulder. Symptoms include gradual onset shoulder pain, particularly with overhead movements.
On this page:
- Symptoms & diagnosis
- Causes & anatomy
Rotator cuff tendonitis symptoms
Symptoms include pain in the shoulder which has developed gradually. The athlete is unable to determin a specific point in time when the injury occured. The shoulder will be painful at rest and be exacerbated by lifting and moving the arm above the shoulder, particularly overhead movements such as in racket sports or swimming. Pain is usually less likely with movements below shoulder height and it may become worse at night.
There is likely to be tenderness when pressing in on the affected tendon which may also feel thickened. A creaking feeling called crepitus may be felt when moving the shoulder. The patient may have had a previous injury such as a rotator cuff strain or partial dislocation. An MRI scan can confirm the diagnosis and identify any tearing of the tendon.
Causes & anatomy
The shoulder joint is a ball and socket joint consisting of the clavicle (collarbone), scapula (shoulder blade) and humerus (upper arm bone). They are all held together by ligaments and muscles which allow movement. Due to the large range of motion required at the shoulder joint and the relative lack of stability, it is common for the rotator cuff muscles to become injured. There are four main muscles which rotate the humerus bone known as the rotator cuff muscles. These are the Supraspinatus, Infraspinatus, Subscapularis and Teres minor.
The supraspinatus muscle runs along the top of the shoulder blade and inserts via the tendon at the top of the arm (humerus bone). This muscle is used to lift the arm up sideways and is also important in throwing sports as it is the muscle that holds the arm in the shoulder when you release what you are throwing. There are massive forces involved in slowing the arm down after you have thrown something but few people bother to train these muscles. A heavy fall onto the shoulder can also result in injuring this muscle.
Over the tendon is a bursa (small sack of fluid used to help lubricate the moving tendon). This bursa can also become trapped inflamed (see Subacromial bursitis). The athlete is more prone to this injury if they overuse the shoulder particularly if the arm is at or above shoulder level. Or if you have had a rupture of the supraspinatus tendon.
The subscapularis is a very powerful muscle which originates from the underside of the shoulder blade and inserts at the front of the upper arm (humerus). Its function is to rotates the arm inwards. When the subscapularis is inflamed it will be painful to move the shoulder and will be tender to touch where it attaches at the front of the shoulder. The subscapularis is often injured by throwers and can be stubborn to treat. A partial rupture of the muscle is more common and will often heal with inflammation.
It is probably the most common cause of shoulder pain which comes on gradually over time or following a rotator cuff strain which has failed to heal properly. Rotator cuff tendinopathy is a more accurate name for the condition. The 'itis' at the end of tendonitis refers to inflammation, which has been shown to be absent in this condition although degeneration of the tendon is the most likely cause. Other similar terms include tenosynovitis which is degeneration of the sheath surrounding the tendon. Causes include:
Overuse either through work or exercises is the most common cause. Activities involving repetitive overhead movements such as throwing, swimming, and racket sports are common causes. Doing too much training too soon is an easy mistake to make and paying attention to early warning signs is important.
Working at a desk for long periods and using a mouse or keyboard can also contribute to overuse, particularly if you have poor posture. The tiny shoulder movements required to work with a computer mouse can add up over time. A forward, rounded shoulder reduces the space in the joint through which the tendons pass. This can lead to the tendons rubbing on the underside of the acromion process at the top of the shoulder joint. Repeated friction leads to pain and degeneration. Thickening of the tendon can make the situation even worse and may lead to an impingement syndrome.
Treatment for rotator cuff tendinopathy consists of two parts. The first aim is to treat the symptoms, reduce pain and inflammation to allow normal movement. The second part is to address the underlying causes and correct.
Rest from activities which cause pain. The more you use the shoulder the longer it will take to heal and it may become chronic. Maintain fitness doing other activities such as running or cycling. Avoid any shoulder exercises or weight training and in particular, avoid the activities which caused the injury in the first place.
Ice or cold therapy
Apply ice or cold therapy to reduce pain and inflammation. Ice can be applied every hour for 10 minutes initially reducing to 15 minutes every 3-4 hours as required to reduce pain and inflammation.
Once inflammation has reduced and you are pain-free, exercises are most important. The normal function of the shoulder should be restored and this involves releasing tension in tight muscles and strengthening weak ones. It is usually the external rotator cuff muscles or the muscles which rotate the shoulder joint outwards which are weak compared with the muscles which rotate the humerus inwards.
In particular, the scapulohumeral rhythm which is the timing of how the shoulder blade moves with the shoulder joint is particularly important. As well as strengthening the lateral rotators, stretching muscles at the back of the shoulder are important.
See more detail on rotator cuff exercises.
A doctor may prescribe anti-inflammatory medication such as ibuprofen which may help in the early stages but less so long term. Ibuprofen should not be taken if you have asthma and your doctor will always check for contraindications before prescribing medication.
Treatments such as ultrasound, interferential stimulation, laser or magnetic field therapy may be beneficial in reducing pain and inflammation.
Sports massage may be used to relax tight muscles in the shoulder in general. If the injury is chronic and not responded to initial conservative treatment such as cold therapy as well as expected then cross friction massage may be applied to the tendon itself. This can break down any adhesion's between the tendon and sheath surrounding it and reduce the injury to its acute stage to encourage correct healing.
Nitric oxide donor therapy
There is some evidence to suggest that nitrite oxide donor therapy patches applied to the shoulder can be successful. Glyceryl trinitrate patches of the correct dose (1.25mg/day) are applied to the shoulder for 24 hours at a time before being replaced.
A corticosteroid is injected into the shoulder at the subacromial space. This may reduce pain and inflammation to allow an exercise rehabilitation program to begin.
A good therapist will help determine the cause of the injury whether that be poor technique or work-related repetitive overuse and identify strategies or changes to avoid the injury recurring. In particular poor posture and muscle imbalances can be corrected with exercises, taping and workspace evaluation.
If there has been bone growth or calcification in the tendon then treatment can be difficult. Extracorporeal shock wave therapy may help along with surgical removal through keyhole surgery could be indicated.