Post by Tim Wescott on Oct 24, 2004 22:43:42 GMT -5
THE INJURY
The subscapularis, supraspinatus, infraspinatus and teres minor are small muscles situated close to the glenohumeral joint (ball-and-socket joint) of the shoulder. Collectively, these four muscles are known as the rotator cuff. Although they have individual actions, their main role is to work together to stabilise the humeral head (ball) in the glenoid (socket).
People are often told that they have injured one particular member of the rotator cuff, with the most common diagnosis being supraspinatus tendinitis. However, it is unlikely that the problem is with just one of the muscles in isolation. The world's top shoulder surgeons refer to such conditions as a 'rotator cuff injury' and consider the picture as a whole.
Although the rotator cuff can be injured by a single traumatic incident, this is not common. Injury to the rotator cuff will usually begin as inflammation (tendinitis) caused by some form of microtrauma (a small but continuous source of irritation). If the cause of the inflammation is not addressed, and continues over a long period of time, partial tears may develop in the cuff that could eventually become complete tears (a tear all the way through one or more of the rotator cuff muscles).
There are three main causes of microtrauma to the rotator cuff:
Primary Impingement.
The coracoacromial arch forms a bridge over the rotator cuff. It is made up of bones and ligaments and is lined by a sac of fluid called the subacromial bursa. The space under the bridge that is available for the rotator cuff is called the subacromial space. Many people will have a naturally small subacromial space, which is just bad luck, but the space can also be reduced by conditions such as osteoarthritis. Whatever the cause of this small subacromial space, repetitive overhead activities (such as throwing a basketball or dusting high shelves) can cause the rotator cuff to become continuously squashed against the coracoacromial arch, causing inflammation of the cuff.
Secondary Impingement.
Many people will have what is called shoulder instability (a lax shoulder joint). This laxity may have been present since birth or may be due to an injury. Often it will have occurred over time due to repetitive overhead activity, poor posture or inactivity. Due to this instability, the rotator cuff has to overwork to stabilise the shoulder, causing it to become inflamed. Eventually, the rotator cuff will become weak and tired, and will not be able to prevent the humeral head from squashing up against the coracromial arch. Because this type of impingement is not due to a small subacromial space, it is called secondary impingement.
Overstraining.
During forceful throwing actions (e.g. javelin throwing), the rotator cuff has to work very hard. With repetitive throwing, the cuff is prone to being overloaded, resulting in inflammation.
SIGNS AND SYMPTOMS
Symptoms of rotator cuff injury include weakness, loss of full movement and shoulder pain. The amount of pain will depend on the extent of the injury. Patients with early-stage inflammation may only have pain with overhead activities, while those with a complete cuff tear may not be able to sleep because of the pain. Physiotherapists have a number of physical tests designed to diagnose the presence and severity of rotator cuff injury. It is also important to look for signs of shoulder instability. X-rays can give clues as to the presence of a rotator cuff injury but an MRI scan is the investigation method of choice to determine whether a tear is present. An ultrasound scan may be just as effective if carried out by an experienced sonographer.
TREATMENT
Tears of the rotator cuff are best treated by surgical repair. Physiotherapy is often affective in treating acute (short-term) and chronic (long-term) inflammation of the cuff where a tear is not present. The first aim of treatment is to reduce the amount of inflammation through electrotherapy, ice (never apply ice directly to the skin) and anti-inflammatory medication prescribed by a doctor. A corticosteroid injection (an injection of a naturally occurring substance that can slow down inflammation) that bathes the rotator cuff, rather than being injected directly into it, is advocated by some doctors. However, even this may carry a risk of causing further damage and should be used with caution.
Once the inflammation and pain has settled, exercises to regain full movement can begin, followed by a carefully-graded strengthening and stabilising programme. Faults in sporting technique that may have caused the problem in the first place must also be rectified.
Operative treatment of chronic inflammation of the rotator cuff may be necessary if no progress is made with physiotherapy. The use of surgery aims to enlarge the subacromial space (subacromial decompression), thus reducing the risk of impingement.
PREVENTION
For athletes, attention must be paid to flexibility, strength and endurance of the shoulder muscles, ensuring that the muscles of the scapula are not neglected. Learning the correct technique and choosing proper equipment are also important. In addition, any increases in the amount of training or competition must be gradual so as not to overload the rotator cuff. Finally, a proper warm up and cool down may also help to prevent injury.
The subscapularis, supraspinatus, infraspinatus and teres minor are small muscles situated close to the glenohumeral joint (ball-and-socket joint) of the shoulder. Collectively, these four muscles are known as the rotator cuff. Although they have individual actions, their main role is to work together to stabilise the humeral head (ball) in the glenoid (socket).
People are often told that they have injured one particular member of the rotator cuff, with the most common diagnosis being supraspinatus tendinitis. However, it is unlikely that the problem is with just one of the muscles in isolation. The world's top shoulder surgeons refer to such conditions as a 'rotator cuff injury' and consider the picture as a whole.
Although the rotator cuff can be injured by a single traumatic incident, this is not common. Injury to the rotator cuff will usually begin as inflammation (tendinitis) caused by some form of microtrauma (a small but continuous source of irritation). If the cause of the inflammation is not addressed, and continues over a long period of time, partial tears may develop in the cuff that could eventually become complete tears (a tear all the way through one or more of the rotator cuff muscles).
There are three main causes of microtrauma to the rotator cuff:
Primary Impingement.
The coracoacromial arch forms a bridge over the rotator cuff. It is made up of bones and ligaments and is lined by a sac of fluid called the subacromial bursa. The space under the bridge that is available for the rotator cuff is called the subacromial space. Many people will have a naturally small subacromial space, which is just bad luck, but the space can also be reduced by conditions such as osteoarthritis. Whatever the cause of this small subacromial space, repetitive overhead activities (such as throwing a basketball or dusting high shelves) can cause the rotator cuff to become continuously squashed against the coracoacromial arch, causing inflammation of the cuff.
Secondary Impingement.
Many people will have what is called shoulder instability (a lax shoulder joint). This laxity may have been present since birth or may be due to an injury. Often it will have occurred over time due to repetitive overhead activity, poor posture or inactivity. Due to this instability, the rotator cuff has to overwork to stabilise the shoulder, causing it to become inflamed. Eventually, the rotator cuff will become weak and tired, and will not be able to prevent the humeral head from squashing up against the coracromial arch. Because this type of impingement is not due to a small subacromial space, it is called secondary impingement.
Overstraining.
During forceful throwing actions (e.g. javelin throwing), the rotator cuff has to work very hard. With repetitive throwing, the cuff is prone to being overloaded, resulting in inflammation.
SIGNS AND SYMPTOMS
Symptoms of rotator cuff injury include weakness, loss of full movement and shoulder pain. The amount of pain will depend on the extent of the injury. Patients with early-stage inflammation may only have pain with overhead activities, while those with a complete cuff tear may not be able to sleep because of the pain. Physiotherapists have a number of physical tests designed to diagnose the presence and severity of rotator cuff injury. It is also important to look for signs of shoulder instability. X-rays can give clues as to the presence of a rotator cuff injury but an MRI scan is the investigation method of choice to determine whether a tear is present. An ultrasound scan may be just as effective if carried out by an experienced sonographer.
TREATMENT
Tears of the rotator cuff are best treated by surgical repair. Physiotherapy is often affective in treating acute (short-term) and chronic (long-term) inflammation of the cuff where a tear is not present. The first aim of treatment is to reduce the amount of inflammation through electrotherapy, ice (never apply ice directly to the skin) and anti-inflammatory medication prescribed by a doctor. A corticosteroid injection (an injection of a naturally occurring substance that can slow down inflammation) that bathes the rotator cuff, rather than being injected directly into it, is advocated by some doctors. However, even this may carry a risk of causing further damage and should be used with caution.
Once the inflammation and pain has settled, exercises to regain full movement can begin, followed by a carefully-graded strengthening and stabilising programme. Faults in sporting technique that may have caused the problem in the first place must also be rectified.
Operative treatment of chronic inflammation of the rotator cuff may be necessary if no progress is made with physiotherapy. The use of surgery aims to enlarge the subacromial space (subacromial decompression), thus reducing the risk of impingement.
PREVENTION
For athletes, attention must be paid to flexibility, strength and endurance of the shoulder muscles, ensuring that the muscles of the scapula are not neglected. Learning the correct technique and choosing proper equipment are also important. In addition, any increases in the amount of training or competition must be gradual so as not to overload the rotator cuff. Finally, a proper warm up and cool down may also help to prevent injury.
