Trigger Point Injections For Back Pain

Trigger point injections are an increasingly common therapy aimed at providing lower back pain relief. If you are considering this treatment, the question becomes: what exactly is a trigger point and why would I want something injected into it?

A trigger point is the sensitive portion of a tight, bound-up muscle. These areas are tender to the touch (hence the name) and cause pain if pressure is applied. Note that an entire tight muscle is not a trigger point, but rather the part(s) of the muscle most sensitive to touch. There can be several such points in one muscle.

These sensitive spots occur when a part of the muscle is in a constant state of contraction. This causes the area of the muscle to feel tight. Additionally, these areas tend to cause a burning ache, as the muscular contraction makes it harder for blood to flow through the muscle. Additionally, this extra tension puts stress on surrounding joints and connective tissue.

I am sure you are thinking that none of these side effects sound pleasant, and it is easy to see why injections for trigger points might seem like a good idea. However, before jumping to conclusions, there are a few other factors to consider. Why have trigger points only become popular to treat recently? Why do they occur in the first place? Will injections help?

Trigger points have only become popular recently because they can't actually be physically observed in the tissue. In other words, if someone was put under for surgery, and a surgeon cut the skin over top of a theoretical trigger point, there would be no difference between the sensitive site and the appearance of the surrounding muscle.

How is this possible? As mentioned earlier, trigger points are the result of muscular contraction rather than any physical phenomenon. When someone is unconscious, these tight areas cease to exist because the brain is no longer creating the muscular contraction. When an autopsy is performed, the sites of contraction can not be seen because the dead person's brain is not causing the contraction that formed the tension in the first place.

A numbing agent, such as lidocaine, is typically injected into the painful area. The thought is if the nerve innervating the muscle is temporarily disabled, the tight portion will relax (which it does). However, when the numbing wears off, the muscular contraction is easily and quickly restored by the brain. For this reason, the success rate of long-lasting relief with this therapy is quite low.

Trigger points could occur for a variety of reasons. One of the two most common reasons is as a protective effect. Tight musculature can be used by the brain to restrict ranges of motion in joints that may be compromised as the result of an old injury. For example, if you have a herniated disc, it is not uncommon to have a few tight muscles in the lower back. These areas exist simply to prevent you from moving your lower back and causing further injury to the herniated disc. In this situation, trigger point injections for back pain could actually cause more harm than good.

The other common reason for sensitive, tight muscles to exist is the result of postural deficits and muscle imbalances. People who work at the computer for long hours tend to develop painful muscles in their upper neck as the body tries to adapt to a new sitting posture (hunched over looking at the monitor). People with muscle imbalances between the front and the back of the hips also tend to develop such painful areas in the hips and low back as these muscles are vying with each other for dominance.