formerly also called myogeloses. These are hypersensitive areas in a palpably tense bundle of muscle fibers.Trigger points, when active, can cause pain during movements and even at rest. A typical characteristic of trigger points is that they radiate pain. For example, trigger points in the lateral gluteal muscles can cause pain throughout the leg.
Active trigger points are very common. A study of American Air Force recruits found that over fifty percent of those studied suffered from them. The origin of the problem is usually constantly tense muscles, for example at computer workstations, or when uniform movements are always performed. Active trigger points are also frequently found in athletes. There they can arise either from a sudden overload of the muscle or from an insufficient regeneration phase.
Just as often, trigger points also arise secondarily, i.e. reflexively, due to other disorders of the musculoskeletal system, for example in osteoarthritis or disc hernia.
Many experts and researchers around the world are now convinced that acute trigger points that are not treated are a frequent cause of chronic pain in the musculoskeletal system, for example back pain.