PT Tip of the Month

Shoulder Pain

The shoulder is a very tricky and complex joint. Injuries to this joint are not only extremely common, but can be disabling to a person’s daily routine. Research shows that 20% to 30% of the general population is affected by rotator cuff pathologies, which only become more prevalent and disabling with age.

Anatomy

The shoulder joint, made up of the humerus and the scapula, is a ball and socket joint. This type of joint allows it to pivot in just about any direction, giving us a wide range of mobility. Additionally the head of the humerus is 3 to 4 times larger than the shallow socket it sits in. Due to this small amount of bone on bone contact, the shoulder is the most mobile joint in the body. Unfortunately, the luxury of mobility has its downfall, as the shoulder is also innately a very unstable joint. To visualize this outside of human anatomy, imagine a golf ball sitting on a tee. The ball can roll on the tee in any direction it wants. Since the golf ball is so big compared to the small and shallow lip on the edge of the tee, it’s very easy for the ball to roll off. When it comes to the shoulder, we use other anatomical structures to counteract this instability and provide the support needed for use. One of the most influential structures for added stability is known as the rotator cuff.

What is the Rotator Cuff?

The rotator cuff is a network of four muscles of the shoulder that surround the joint. These muscles are the supraspinatus, infraspinatus, teres minor, and subscapularis. These muscles, originating from the shoulder blade send tendons that fuse together to attach to the head of the humerus, allowing movement to occur. As larger muscles initiate movement of the shoulder, the small muscles of the rotator cuff work as a unit to pull the ball into the socket and provide support around the edges of the socket.

 

 

What Can Go Wrong?

Just above the shoulder joint is a piece of bone coming off the scapula. This is called the acromion. The acromion is important as many muscles attach here to allow the shoulder to move, however it can also be a source of shoulder problems. Ideally, we want this bone to be flat over the shoulder joint, however in some cases it is curve or hooked. The supraspinatus tendon and the tendon of the biceps muscle run underneath the acromion. An acromion that is curved, hooked, or has developed bone spurring can result in increased rubbing or friction leading to pathology such as tendinitis or tendinosis. To make matters worse, poor posture can tilt the acromion forward, closing down that narrow space and increase the likelihood of this rubbing further. Overtime, this problem can lead to rotator cuff tendinitis or tendinosis.

What is Tendinitis and Tendinosis?

Tendinitis refers to acute inflammation and irritation of the muscle tendon. With this, microtearing of the tendon can occur. Tendinosis is a more chronic problem resulting in a degeneration of the collagen that makes up the tendon and is frequently associated with overuse and repetitive movements.

Signs and Symptoms

Symptoms of rotator cuff tendinitis are classically described as having sudden pain when reaching overhead, particularly at the very top of the movement or with lifting, a dull aching pain with activity or at rest, or radiating pain in the front of the shoulder to the side of the upper arm. Many people with this condition have pain and difficulty with everyday activities such as brushing their hair or reaching for objects overhead. As it worsens, the shoulder can feel stiff and weak and you can develop pain at night. If the tendon ruptures patients can experience severe weakness with lifting or rotating the arm, significant pain raising or lowering the arm, and pain at rest or at night, especially when lying on the affected side. These tears can occur acutely from falls and lifting something too heavy, or overtime when the tendon chronically degenerates and wears down.

Treatment

If you are currently experiencing pain, it is always best to seek a medical opinion for proper diagnosis. Those who are diagnosed with rotator cuff dysfunction may be sent to physical therapy for treatment, in some cases given cortisone injections to reduce inflammation, or undergo surgery in severe cases, such as cuff tears, to repair the torn muscle. If PT is ordered, a physical therapist will initially focus on restoring normal motion to your shoulder. If you have difficulty reaching behind your back or overhead, stretching exercises will be performed to restore normal joint mobility. Joint mobilizations to stretch the posterior capsule ligaments of the joint can be very effective in relieving pain in the shoulder. Once your pain improves, your therapist can start you on a strengthening program for the rotator cuff muscles.

If you are experiencing signs and symptoms of shoulder pain and would like to be scheduled for a physical therapy evaluation, please call 617-232-PAIN (7246) for our Brookline office or 617-325-PAIN (7246) for our West Roxbury office.

References

  1. Shoulder Impingement/Rotator Cuff Tendinitis-OrthoInfo - AAOS. (n.d.). Retrieved April 26, 2015, from http://orthoinfo.aaos.org/topic.cfm?topic=a00032
  2. Rotator cuff problems: MedlinePlus Medical Encyclopedia. (n.d.). Retrieved April 26, 2015, from http://www.nlm.nih.gov/medlineplus/ency/article/000438.htm
  3. Rotator cuff injury. (2015, March 17). Retrieved April 26, 2015, from http://www.mayoclinic.org/diseases-conditions/rotator-cuff-injury/home/ovc-20126921

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