Trigger point therapy is being integrated into veterinary medicine along with manual manipulative therapies such as chiropractic and osteopathic care. In human medicine, this combination is now called acupuncture osteopathy. Acupuncture osteopathy has been defined by Mark Seem as: “the release of myofascial and musculoskeletal obstruction to restore normal flow through acupuncture needling.”(1) Meridian-based acupuncture is similar in intent to one form of acupuncture osteopathy. Acupuncture may effect a physical manipulation of the body through the insertion of needles into the muscles and connective tissue, improving the normal flow of blood, energy, and nutrients by releasing myofascial and musculoskeletal constrictions.(1) Many of these acupuncture points treated may also be related to trigger points.
Trigger point therapy is well recognized as a pathologic entity in human medicine.(2) Only limited information is available on animal trigger point anatomy, etiology, histology, and therapy.(3) Trigger points have been described in horses and dogs. Trigger points may be palpated as hard nodular structures within muscle or fascia. When localized in a muscle, they may be palpated as a taut band of muscle fibers. They are usually hypersensitive upon palpation, which may cause a dog to wince, cry, or bite. The most stoic animal may react vigorously.
Though they may occur anywhere in the body, trigger points normally occur in stable anatomic spots; many trigger points in both man and animals coincide with acupuncture points. Trigger points (TPs) weaken and prevent lengthening of the muscle in which they are localized, may cause referred pain in a specific zone, and eventually cause autonomic disturbance. Muscle shortening may impair the motion of adjacent joints and further enhance joint trauma.
The etiology of trigger points is not yet fully understood, though several factors may be involved, such as arthritis, strain, trauma, stress, postoperative status, or viral infections. In dogs, trigger points have been observed secondary to disk disease as well as a sequellae of other primary lameness. It is not uncommon for the animal to still be lame after the original cause was resolved. This is often due to secondary trigger points surrounding the affected area. Once these trigger points are treated, the lameness often resolves.
Trigger points are treated by releasing the point; using either noninvasive or invasive techniques. Noninvasive techniques include stretching, deep tissue massage, transcutaneous electrostimulation, and laser therapy. Invasive methods consist of dry needling techniques or local injection. The fluids used in injection techniques include lidocaine, procaine, vitamin B, homeopathic injectables, or corticosteroids. When a trigger point is injected, a muscle twitch is often observed. Approximately one to three treatments may be necessary to release a trigger point.
Nine trigger points have been described in dogs, although many more exist.(4) Trigger points have been identified in paravertebral muscles as well as in the triceps, infraspinatus, quadriceps, pectineus, iliocostalis lumborum, peroneus longus, semitendinosus, and gluteus medius muscles.(3)
Trigger points may also be related to clinical and subclinical degenerative joint disease, intervertebral disc disease, spondylosis, as well as vertebral fixations or misalignments. Depending on the degree of sensitivity of the trigger points, they may be released prior to, or following, manipulative therapies such as osteopathy and chiropractic.
Incorporating trigger point therapy into a veterinary practice is relatively easy if their palpation and diagnosis is added to the routine physical examination; the treatment is relatively simple and the results may be quite rapid and dramatic. Clinical cases will be discussed.
1. Seem, M., A New American Acupuncture, Acupuncture Osteopathy, Blue Poppy Press, Boulder Co, 1993. pg.6-8.
2. Travell, J. and Simons,D., The Trigger Point Manual. Williams and Wilkins, Baltimore, 1983.
3. Janssens, L., Trigger Point Therapy, in Schoen, A., Veterinary Acupuncture, Ancient Art to Modern Medicine, 2nd edition, Mosby Publ. Inc., St. Louis, MO. 2001.
4. Janssens, L., Trigger points in 48 dogs with myofascial pain syndrome. Vet Surgery 20:274-278. 1991.
5. Robinson, N., Acupuncture and Manipulative Therapy: A Perfect Marriage.In A. Schoen, Veterinary Acupuncture, Ancient Art to Modern Medicine, 2nd edition, Mosby Publ. Inc., St. Louis, MO. 2001.