Have you ever had a Charlie horse in your muscle? If so, then you know how it feels. The whole muscle goes into a painful spasm, and the only thing that helps is gently lengthening and stretching the muscle back out. Trigger points are a small portion of muscle spasming in a miniature Charlie horse. If you have enough trigger points, you‘ll start to feel serious pain and experience limited muscle mobility.
A trigger point is a hyper-irritable knot in a taut band of muscle (myofascia). They are painful on compression and can produce a jump sign or local twitch response when direct pressure is applied, muscle dysfunction and referred pain or tenderness. A jump sign is a transient visible or palpable contraction or fasciculation of the myofascia. Referred or reflective pain, is pain perceived at a location other than the site of the painful stimulus. Pain is reproducible and does not follow dermatomes, myotomes, or nerve roots. There is no specific related swelling or neurological deficit. Pain from a myofascial trigger point is a distinct and constant pattern.
Trigger points are often caused by lack of movement, poor posture, trauma, psychological stress, muscle splinting above a bow or joint injury, repetitive strain, overuse of muscles, restricted range of movement or any combination of these.
One thought on how they develop is that some sacromeres become switched on for too long and those fibers get stuck in the shortened state. Another thought is that hyaluronan becomes thickened locally, increasing the viscosity in the myofascial tissue, altering its ability to distribute tensile force across adjacent structures and causing a sensitization of embedded nerve endings. Trigger points are commonly found in most superficial muscles and can develop anywhere there’s skeletal muscle tissue.
These tight bands of myofascial tissue become so tense that they limit blood flow to muscle tissue. This creates pain and a metabolic crisis in the muscle tissue; there is pain and tightness which require oxygen and nutrients to heal, but those nutrients are unable to get to the muscle due to decreased micro-circulation from the tightness. The pain-decreased circulation-pain cycle begins, and this cycle can be difficult to interrupt, causing chronic pain. When widespread it is sometimes referred to as Myofascial Pain Syndrome and it often goes undiagnosed in horses.
There are different types of trigger points.
Primary or Central trigger point is an active trigger point based around the center of a muscle belly.
Secondary or Satellite trigger point will develop in response to existing central trigger points in surrounding muscles. They can present in the form of a cluster and may spontaneously withdraw when the central trigger point is healed. Think of how a knot in your clothes would put extra stress on the fabric around it.
Attachment trigger points develop in the muscle-tendon (myotendinous) junction (MTJ) and will be painful or tender and cause instability and pain in the related joint. The MTJ is where force is being transferred from the muscle to the tendon. While many believe this is the definitive location where the muscle meets the tendon, the MTJ actually tapers a lot less definitively and several MTJs converge within the muscle belly itself. This is known as the intramuscular tendon where the myofibrils attach to the tendon within the muscle itself, and is another location site for trigger points.
An Inactive or Latent trigger point can develop anywhere and will feel like lumps under your finger tip, but are not painful. They will still increase the stiffness of the muscle and increase the risk of tissue tears.
Passive trigger points hurt at their exact location. If your horse has a painful trigger point in their shoulder and someone presses on it, the pain will be felt right where the pressure is on the point.
An active trigger point causes tenderness and referral pain pattern on palpation. If someone presses on an active trigger point in your horse’s shoulder, they might also feel pain in their forearm or their neck. Central trigger points are usually active and some satellite trigger points may also active. Inactive trigger points can eventually become active if there is a provocative factor.
While humans can ask for help when they hurt, a horse relies on their owners, trainers and caretakers to notice and respond when something is going wrong for them.
You may notice a spot that elicits a pain response, altered motor recruitment in either the affected muscle or in related muscles, changes in range of motion, postural compensations, tension headaches, restricted poll, TMJ, painful movement, shortened stride or uneven steps, a change in behavior when being handled or ridden or a combination of any of these.
Trigger points do not go away on their own. If rested they may regress to a state where they stop referring pain but they will still be there and still cause muscle restriction and soreness.
A Massage incorporating Trigger Point Therapy can be very effective in reducing pain, restoring movement and strength and reducing stress on joints. Trigger point therapy requires skill and sensitivity. Relief comes from softening and releasing the myofascial knots and trigger points to reduce or eliminate the point and associated pain. Red light therapy can be a great help for very painful areas. Massage stimulates the circulation bringing oxygen and nutrients to the area. It soothes and separates the myofascia and releases tension in the tissues. Massage also releases endorphins serotonin and dopamine leaving your horse with reduced pain and a relaxed sense of well-being. Various levels of pressure are then applied directly to the trigger points. This temporarily cuts off circulation to the tissue. This cutting off of circulation increases a chemical called nitric oxide. Nitric oxide signals your body to open up microcapillaries, thus bringing in more blood flow and breaking the pain-spasm-pain cycle. Once treated the affected areas are brought through their range of motion to help realign the fibers in the correct direction and encourage the horse to integrate those changes neurologically. Some therapists will recommend somatic exercises to help the horse become aware of and use it’s new range of motion. Kinesiology Tape can help support the changes that have been made by the bodywork and there is research supporting the idea that KT can help release trigger points up to a few centimeters away from the taping.
One session can bring great relief from pain and improve their ability to use their muscles. Many horses with old, chronic trigger points will require multiple sessions to really work through them. Your Massage therapist may be able to give you exercises and techniques to use in between sessions to facilitate healthier myofascia. One of the most effective ways to proactively maintain healthy muscles and fascia is to establish a regular massage routine for your horse.
If your horse has trigger points, sore facia and knotty, tight muscles, the pain and restrictions that come with them can make it hard to for your horse to move comfortably and stay sound.
Massage with Trigger Point Therapy can release stressed muscles and built-up tension so they can perform at their best for you.
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