LAS VEGAS—“If we could give every individual the right amount of nourishment and exercise, not too little and not too much, we would have found the safest way to health.” —Hippocrates (460-733 BC)
With that advice, Marie Hoeger Bement, PT, PhD, Associate Professor in the Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, began her presentation on the effects of exercise-induced analgesia in patients with chronic pain.
Challenges in prescribing exercise is how to determine exercise type, dosage, and progression, and how exercise-induced increases in pain should be approached, given that pain response changes over time in patient populations, she said.
Evidence from systematic reviews have shown significant improvements for knee osteoarthritis, chronic low back pain, fibromyalgia, and shoulder pain, with the treatment effect increasing with the number of exercise sessions for low back pain and osteoarthritis, Dr. Hoeger Bement said. Smaller effect estimates were shown for neck pain, hip osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis.
However, several limitations exist with respect to exercise and chronic pain, including quality issues (poor description of “dosage”), compliance, and whether programs of relatively short duration can predict long-term response. Few mechanistic studies have examined impact on central sensitization and descending inhibition.
Dr. Hoeger Bement reviewed data on the effects of exercise for osteoarthritis, acute and chronic low back pain, fibromyalgia, and neuropathic pain.
For osteoarthritis, both land-based and aquatic exercises have shown a benefit by reducing pain and improving physical function. However, data are insufficient to provide useful guidelines on optimal exercise type or dosage.
For chronic low back pain, there is strong evidence for effectiveness of manipulation, back school, and exercise therapy. However, exercise was found ineffective for acute low back pain.
For fibromyalgia, supervised aerobic exercise training was found to have beneficial effects on physical capacity and symptoms, such as tender point pain pressure threshold and pain. A review of alternative/complementary exercise for symptoms of fibromyalgia reported positive outcomes for Qigong, Tai Chi, and yoga; however, another study found only yoga yielded significant effects on pain at the final treatment.
A 10-week supervised aerobic and strengthening exercise program in patients with diabetic peripheral neuropathy found significant reduction in worst pain—but not “current” or “usual” pain—as well as neuropathic symptoms and increased intraepidermal nerve fiber branching from proximal skin biopsy. Another study found regular exercise reduced neuropathic pain through central opioid mechanisms.
Dr. Hoeger Bement concluded by acknowledging that despite reported pain relief, exercise frequently is discontinued; therefore, when prescribed, exercise programs require supervision, integration into daily activities, patient self-monitoring and education, and follow-up.