Your shoulder is made up of three bones:
- your upper arm bone (humerus)
- your shoulder blade (scapula)
- your collarbone (clavicle).
The shoulder is a ball-and-socket joint: The ball, or head, of your upper arm bone fits into a shallow socket (glenoid fossa) in your shoulder blade.
Your arm is kept in your shoulder socket by your rotator cuff your rotator cuff. The rotator cuff is a network of four muscles that come together as tendons to form a covering around the head of the humerus.
The muscles that form the tendons are the supraspinatus, in.fraspinatus, teres minor, and subscapularis. The rotator cuff attaches the humerus to the shoulder blade and helps to lift and rotate your arm. In addition to creating motion at the shoulder, they are also important for providing stability.
There is a lubricating sac called a bursa between the rotator cuff and the bone on top of your shoulder (acromion). The bursa allows the rotator cuff tendons to glide freely when you move your arm. When the rotator cuff tendons are injured or damaged, this bursa can also become inflamed and painful.
There are two main causes of rotator cuff tears: injury and degeneration.
- Acute Tear- If you fall down on your outstretched arm or lift something too heavy with a jerking motion, you can tear your rotator cuff.
- Degenerative Tear - Most tears are the result of a wearing down of the tendon that occurs slowly over time. This degeneration naturally occurs as we age.
Several factors contribute to degenerative, or chronic, rotator cuff tears.
- Repetitive stress - Repeating g the same shoulder motions again and again can stress your rotator cuff muscles and tendons. Baseball, tennis, rowing, and weightlifting are examples of sports activities that can put you at risk for overuse tears. Many jobs and routine chores can cause overuse tears, as well.
- Lack of blood supply. As we get older, the blood supply in our rotator cuff tendon s lessens. Without a good blood supply, the body's natural ability to repair tendon damage is impaired. This can ultimately lead to a tendon tear.
- Bone spurs. As we age, bone spurs (bone overgrowth) often develop on the underside of the acromion bone. When we lift our arms, the spurs rub on the rotator cuff tendon. This condition is called shoulder impingement, and over time will weaken the tendon and make it more likely to tear.
- Age - more common over the age of 40
- Occupation - those who are required to use repetitive motions, e.g. painters and carpenters
- Athletes - repetitive overhead activities such as pitching and tennis
- Poor Posture -poor posture can cause a muscle or tendon to become irritated and inflamed when you using your arm to throw or perform overhead activities.
- Weak Shoulder Muscle -weaker muscle are more susceptible to injury
The most common symptoms of a rotator cuff tear include:
- Pain at rest and at night, particularly if lying on the affected shoulder
- The pain can also radiate into your neck, arm or with specific movements
- Weakness when lifting or rotating your arm
- Crepitus or crackling sensation when moving your shoulder in certain position
You will often find it difficult to do routine things such as:
- Reaching behind your back
- Reaching into a cabinet
- Combing your hair.
Tears that happen suddenly, such as from a fall, usually cause intense pain. There may be a snapping sensation and immediate weakness in your upper arm.
Your Physical Therapist will ask questions about your medical history, your injury, and your pain. Your PT will then do a physical examination of the shoulder. The physical exam is most helpful in diagnosing a rotator cuff tear. A complete tear is usually very obvious. Your PT can move the arm in a normal range of motion, but you can't move the arm yourself, you most likely have a tom rotator cuff.
Your doctor may request X-rays imaging of your shoulder. X-rays will not show tears in the rotator cuff. However, your doctor may want you to have a shoulder X-ray to see if there are bone spurs, a loss of joint space in the shoulder, or a down sloping (hooked) acromion.
Your doctor may also want you to have a MRI. These studies can better show soft tissues like the rotator cuff tendons . They can show the rotator cuff tear, as well as where the tear is located within the tendon and the size of the tear. An MRI can also give your doctor a better idea of how "old" or "new" a tear is because it can show the quality of the rotator cuff muscles.
Initial treatment is usually rest and anti inflammatory medication, such as aspirin or ibuprofen. Treatments such as heat and ice focus on easing pain and inflammation. Hands-on treatments and various types of exercises are used to improve the range of motion and help reduce the pain in your shoulder and the nearby joints and muscles. Later, you will do strengthening exercises to improve the strength and control of the rotator cuff and shoulder blade muscles. Your therapist will help you retrain these muscles to keep the ball of the humerus in the socket. This will help your shoulder move smoothly during all of your activities.
If all of these efforts to improve your shoulder condition fail, our Physical Therapist may refer you for surgical evaluation. Surgical repair may be necessary to allow you to regain the use of your shoulder and reduce your pain.