A trigger point is a hypersensitive spot in any muscle, it can be either active or latent, that has the ability to cause pain or other clinical manifestations such as: muscle shortness, weakness, and reduced range of motion.
A clinically active trigger point means that it is primarily pain expressive. Not only does it cause pain, it causes the muscles to exhibit tautness or shortening, spasm, and weakness relative to its normal state (absent trigger points) or in relation to the same muscle on the opposite side of the body.
The muscle will still possess its developed “potential” strength; but, the presence of trigger points renders the muscle weaker, as long as the trigger point(s) remain. Once the trigger points are completely eliminated the muscle will once again return to its normal strength. If the muscle has become weakened due to use avoidance, then when trigger points are eliminated it will have the ability to be fully strengthened when exercised.
As just stated, the muscle may have become weaker than it originally was due to disuse. Pain, trigger point induced weakness, or dysfunction will cause the sufferer to avoid full use or exercise and over time the muscle(s) that harbor any trigger points will become deconditioned.
The problem is that the longer a trigger point is present (active or latent) the more weakness occurs and the more dysfunctional the muscle becomes despite efforts to strengthen it.
The only difference between an active versus a latent trigger point is that the latent trigger point will not be pain expressive unless it is sufficiently compressed.
Latent trigger points may persist for months, even years, before they become active trigger points. It is possible for latent trigger points to remain quiescent over one's lifetime. But the latent trigger point will still cause dysfunction, or prevent full motion and normal muscle strength.
From an objective (functional) point of view, not a subjective (pain) one, there is no difference between active versus latent trigger points.
Bear in mind, failure to eliminate latent trigger points will most likely prevent elimination of active trigger points. ALL trigger points should be treated and eliminated, as much as possible, or they will prevent optimal function, not only in muscles harboring trigger points, but of the entire body in general.
Regardless of whether the trigger points are active or latent, they will predispose one to:
Some of the more common signs and symptoms that can be present from latent or active trigger points found in the lower back and its associated muscles are:
All of these signs and symptoms, whether due to active or latent trigger points, will prevent or interfere with normal muscle and body function.
This is not only important for carrying out activities of daily living within the general population, but it becomes more so within the athletic world.
Trigger points can render athletes weak, unable to perform optimally, and even disabled. With the presence of trigger points, an athlete will be prevented from achieving maximum performance. It will create abnormal rhythm, strength, range of motion, interfere with training, and hinder training or injury recovery.
If either active or latent trigger points are present and allowed to persist, they can be the difference of a multi-million dollar record-setting career or an athlete who never achieves his or her full potential.
To summarize: the only difference between active versus latent trigger points is active trigger point cause conscious pain. All other signs can be present. Failure to fully eliminate all trigger points, active or latent, will keep the muscle(s) from behaving in a normal fashion. Trigger point containing muscles will be abnormal relative to range, strength, injury prevention, and maximum exercise recovery and performance, regardless of whether one is a member of the general population performing activities of daily living, an amateur or professional athlete, a weekend warrior, or leisure hobby enthusiast.