This editorial was brought to me during my residency at Harris Health. It is written by Jason Silvernail on the website SomaSimple.
As therapists we often deal with 2 types of pain: Chemical and Mechanical. Understanding the difference between the two is important because it allows you to explain to your patients "why" they are experiencing pain. Chemical Pain is associated with inflammation, and responds positively to anti-inflammatory medication and rest. Mechanical Pain is more complex! It is due to prolonged pressure or tension on nervous tissue. When you see a patient with mechanical pain, they may have questions regarding why their MRI did not show anything significant OR why their medications are not working. This is because Mechanical Pain is due to how the tissue feels, and not the way the tissue looks. There is no acute inflammation and no acute tissue damage. Mechanical pain is a chronic irritation. To fix mechanical pain, we need prescribe movements that relieve the tension that is being placed on the nervous system. This specific movement will gradually or immediately allow the patient to experience less pain. The patient needs to be regularly reversing the postures that are placing tension on their nervous system. This is where doing your Home Exercise Program regularly becomes so important. Sometimes it can be difficult to tell a patient to MOVE when they are in pain, but by educating them that the specific exercises you are prescribing are actually taking tension off the involved structures can be a great for compliance.
The last point I will touch on is how many sets and reps should be prescribed for mechanical pain. As therapists, we know how many repetitions to prescribe for strength training, neuromuscular re-education, and power, but how many reps do you prescribe for pain? The answer is unique to each patient and will vary based on comorbidities, irritability level, etc... I would recommend starting with a high repetition, low load dosage. This will minimize the risk for compensations, decrease the risk of increasing symptoms, and hopefully get the patient performing them more frequently.
Silvernail, J. "Understanding Mechanical Pain." Somasimple.com. Web. 14 Dec. 2013.