How do we treat
There is a lack of research being performed on the pathophysiology and treatments of muscle pain. This void in the medical community is one that FRAME is attempting to fill. The research articles below are a starting point for understanding muscle pain and the treatments being studied.
80% relief of low back pain with just exercise
This article evaluated the effects of the exercise program “The Y’s Way to a Healthy Back”; a six-week exercise program for people with low back pain that was established at YMCAs throughout the United States. The large-scale study included 11,809 people who completed the exercise program from 1977-1981. Classes met twice weekly with trained instructors and participants exercised at home on the days when the classes did not meet.
About 80 percent of the nearly 12,000 participants reported a decrease in discomfort, including those who had previously undergone back surgery. A decrease in pain correlated with adherence to the program and with measured improvement in strength and flexibility.
Kraus, H., Nagler, W., & Melleby, A. (1983). Evaluation of an exercise program for back pain. American Family Physician, 28(3), 153-8.
How needles treat myofascial pain
Karel Lewit discovered that the anesthetic employed in injections (injectant) into pain spots did not affect the overall outcome of the treatment. Rather, it was the physical needling that treated the pain. In studying short and long-term studies of dry needling, Lewit analyzed that immediate relief was achieved in 86.8% of the cases without hypesthesia (injectant).
This immediate effect is called the “needle effect.” The effectiveness of treatment was related to the intensity of pain produced at the trigger zone, and the precision with which the site was located by the needle.
Lewit, K. (1979). The needle effect in the relief of myofascial pain. Pain, 6(1), 83-90.
Can stress alone cause pain?
This article investigated the influence of stress on dorsal horn neurons in rats. Would stress alone cause pain? Rats were put in a stress-induced state for various periods of time, and single dorsal horn neurons were recorded using microelectrodes.
The neuronal response behavior demonstrated increased input from deep soft tissues and significant increase in resting activity. However, the pressure-pain threshold of the low back remained unchanged. The study therefore shows that stress alone can sensitize dorsal horn neurons, which may explain increased pain in the low back with stress. The increased resting activity may lead to spontaneous pain.
Hoheisel, U, et al. Immobilization stress sensitizes rat dorsal horn neurons having input from the low back (2015). Eur J Pain. 19:861-870.
Pathophysiology of Muscle Pain
An extensive literature review was performed in attempts to better understand the pathophysiology of muscle pain. In researching this topic, predominantly looking at neuroanatomical and electrophysiological experiments on rats, several items were of note. Muscle pain is evoked by nociceptors, stimulated by ATP and a low tissue pH.
Excitation of muscle nociceptors can lead to central sensitization, which can lead to referred muscle pain. The model of increased peripheral nociceptive activity causing central sensitization may explain why patients who have localized trauma leads to generalized, diffuse pain.
Mense, S. (2008). Muscle pain: mechanisms and clinical significance. Deutsches Ärzteblatt International, 105(12), 214.
Multiple clinical trials have been conducted to determine the efficacy of laser therapy, which have had mixed results. There are many types of lasers used in various ways, making it important to understand which laser may be most effective for specific types of pain. In this study, 100 patients with chronic low back pain (average age of 60) were randomly placed into two groups.
One group performed exercises for three weeks with laser therapy while the other group performed the same exercises for three weeks with a placebo laser. The group who received the laser therapy along with the exercises had a significant decrease in pain levels compared to the placebo group.
Vallone, F., Benedicenti, S., Sorrenti, E., Schiavetti, I., & Angiero, F. (2014). Effect of diode laser in the treatment of patients with nonspecific chronic low back pain: a randomized controlled trial. Photomedicine and laser surgery, 32(9), 490-494.
Diagnosing Myofascial Trigger Point Syndrome
An extensive literature review of 93 articles was performed to understand how clinicians diagnose myofascial trigger point pain syndrome. There were 19 different diagnostic criteria identified in the review. There was no consistent pattern except the pair of criteria “tender point in a taut band” and “predicted or recognized pain referral” was used in over half the studies.
Because there is no reliable diagnostic criteria currently established, research papers must be transparent about their method of diagnosing myofascial trigger point pain syndrome, and caution must be placed on any claim for effective interventions for this condition.
Tough, E. A., White, A. R., Richards, S., & Campbell, J. (2007). Variability of criteria used to diagnose myofascial trigger point pain syndrome—evidence from a review of the literature. The Clinical journal of pain, 23(3), 278-286.