Shoulder Pain
Shoulder pain is a big pain. Many of my patients with spinal cord injury come to me with complaints of shoulder pain.
Prevalence
It has been reported in the literature that anywhere from 30 to 78% of patients with spinal cord injury have shoulder pain. That number varies a lot because of the definition of pain. Where is the pain? Is it throughout the upper limb, confined to the shoulder, wrist, or elbow? It can also have to do with the timing of the pain and when the question was asked. Altogether, we know that the incidence of pain is higher in tetraplegia than it is in paraplegia. It is more likely to appear in the first 6 to 12 months post-injury, and if it does appear in that first 6 to 12 months post-injury, it will be a recurrent problem over the patient's life if it's not addressed appropriately.
Main Causes
We know that there are a few main causes of shoulder pain in patients with spinal cord injury resulting from their neurological injury.
Neurogenic shoulder instabilty. The first is the neurogenic shoulder instability. Often with a spinal cord injury comes paralysis, weakness, and muscular imbalance. These change the bio-mechanics and the kinematics of the shoulder as the patient is moving.
Overuse/repetitive motion. Patients with spinal cord injury are using their arms in place of their hips in a lot of cases, and the shoulder joint was not designed to do that. Most significantly, patients engage in transfers andwheelchair propulsion all day long, putting a lot of stress on their shoulders.
Cervical and upper quadrant issues. These can be related to the injury itself, or they can be acquired over the course of the patient's life. In many cases, there are neck and scapular issues that contribute to the shoulder pain.
Neurogenic pain. There can also be neurogenic pain resulting from the spinal cord injury. The nerves are damaged or demyelinated and may carry bad information. This could be like static in a telephone wire and result in aberrant messages or pain.
Degenerative changes. There can be degenerative changes over time. These happen really fast in patients with spinal cord injury, although mimic that which we see in older people. Again, this is related to the fact that they are using their shoulders so much more than they were originally designed for.
Impact
If you have had any sort of pain in your life, you know it can have a significant impact on your overall function and quality of life. Mostly, this results in a worsening disability. Up to 80% of patients with shoulder pain report an interruption in sleep. Twenty-six percent report that they need additional help with functional activities. Thirty-eight percent report a reduction in independence, while 21.4% report that they are unemployed because of their shoulder pain. This is a huge issue, and obviously this associated disability correlates strongly with a decreased quality of life. There are also increases in transportation costs, caregiver costs, environmental modifications, and additional healthcare costs associated with spinal cord injury and shoulder pain.
