Monthly Topics
Understanding Shoulder Pain and Impingement Syndrome
By Karen W. Smith, PT

The shoulder is a very mobile joint allowing great flexibility and mobility to perform daily activities or sports performance with precision and ease. However, this mobility comes with a price; the more mobility a joint offers, the more vulnerable it is to injury and repetitive strain-type injuries. Shoulder pain and dysfunction affect millions of people with the severity of intervention ranging from a few days of rest to physical therapy intervention and more drastic surgical intervention. This usually occurs in the dominant arm, although not always.

Anatomy:


The shoulder is made up of several structures including bones, ligaments, joint capsules, tendons, muscles and bursa. Tendons connect muscle to bone and provide the dynamic stability for the shoulder joint. The bursa is a fluid-filled sac that helps with reducing friction. The soft tissue structures including the tendons, muscles and bursa will be the structures that are the primary sources of the impingement type pain in the shoulder (refer to the diagram for visual clarification).

What are the Causes of Shoulder Pain:
Most shoulder pain is experienced when one or more of these structures (tendons, muscles and bursa) is compromised or impinged (pinched). Impingement pain is usually the result of the rotator cuff muscles, long head of the biceps or bursa getting pinched under the bony arch of acromion and collar bone by the head of the humerus (upper arm bone) as the arm is raised above the head. Repetitive use in this fashion leads to irritation and inflammation of the pinched tissue that ultimately results in pain and further injury.

Tendonitis/Bursitis:
 Irritation of the tendons and bursa can occur gradually over time or be associated with an acute onset or single episode of over-activity (e.g., pitching excessively, painting a room, heavy lifting, or any activity that one is unaccustomed).

Injury:
A fall on the shoulder or blow to the shoulder can cause damage and tears to the joint capsule and/or tendon and muscles, also leading to pain.
Instability:
 Commonly due to a previous injury where as one might feel as if the shoulder is slipping out of joint when lifting arm out to the side.

Changes in Shoulder Biomechanics:
The dynamic relationship that exists between muscles, joint capsule and bony structures to provide the shoulder flexibility and stability. When one or more structures are compromised by injury or instability, the shoulder dynamics no longer function as intended and cause more damage and irritation to the soft tissue. Biomechanical abnormalities, unfortunately, translate into pain and lack of function that in turn can lead to further pain and greater impingement and damage to already compromised soft tissue. Pain, weakness and tightness of the shoulder structures alter the way the joint and muscles work together to move the arm and thus set up a scenario that may lead to more damage and injury to the tendons, ligaments and bursa. This damage translates to the obvious and unfortunate experience of greater shoulder pain over time.

Common Complaints:
Impingement pain is the result of irritation to soft tissue in the shoulder.Physical Therapy intervention is instrumental in alleviating pain, decreasing inflammation, restoring normal range of motion and biomechanics and strengthening to achieve the desired outcome of resuming previous pain-free activity! This outcome is most successful with PT intervention in the early stages after injury or the onset of pain.

Pain with use of arm, especially lifting or over-head movements
Pain with lying on effected side and difficulty sleeping
General pain and tenderness around shoulder joint
Pain along the outside of the arm, but not past the elbow
Inability to move arm through normal movement patterns
Inability to perform previous daily activities

What can I do and when should I Seek Medical Intervention?

Rest from the activity that caused the pain
Seek medical attention and physical therapy intervention sooner than later to minimize further injury and damage to soft tissue and maximize recovery outcome
Use Ice or anti-inflammatory medications as prescribed from Physician

How is impingement syndrome of the shoulder treated?

Physical Therapy Intervention:

Comprehensive Evaluation: To identify problematic structures, weakness, tightness, motor firing patterns and biomechanical dysfunction.
Modalities: Ice/Cryotherapy, Ultrasound, Electrical stimulation, phonophoresis and iontophoresis are commonly used physical modalities in the acute phase to reduce pain, decrease inflammation and increase circulation to facilitate the healing process. Biofeedback may also be used later to address muscle retraining and motor firing patterns to restore normal biomechanics.
Manual/ Hands on Techniques: Joint mobilization and passive range of motion are used to assist loss of mobility of the joint capsule and muscle shortening. Deep tissue mobilization works on the tendons and muscles to break up scar tissue and adhesions that if not addressed will continue to cause problems long after the pain has subsided.
Strengthening: Strengthening weak musculature is important to re-establish normal shoulder function and prepare the shoulder to handle physical demands. A specific program is designed to address individual physical requirements.
Stretching: A program designed to stretch tightness in the joint capsule and musculature.
Functional Activities: Functional activities are designed to meet individual needs and are important to return safely to previous activity level. This phase incorporates specificity of training (e.g., carpenter would work on hammering, over head activities and/or lifting).
Home Exercise Program: All phases of rehabilitation are augmented by a home program specific for that particular phase of recovery.