Lecture 11 Flashcards
(50 cards)
What are trigger points?
Hard, discrete palpable nodules in a taut band of skeletal muscle
What type of pain can trigger points cause?
Localised pain within the muscle or radiating pain
What are the types of trigger points?
Active: Spontaneously painful
Latent: Only painful on compression
What does the use of the term Myofascial Pain Syndrome (MPS) imply?
A specific condition which is distinguished from other soft tissue pain disorders such as fibromyalgia, tendonitis or bursitis.
What does MPS present as?
Regional pain, sometimes with referred pain, often accompanied by increased tension and decreased flexibility.
What does the Cinderella Hypothesis explain?
It explains how musculoskeletal disorder symptoms can arise from muscle recruitment patterns during low to moderate physical exertion over time.
In what types of people is the Cinderella Hypothesis especially relevant?
Office workers, musicians, dentists—those performing prolonged, low-level static tasks.
What is Henneman’s size principle?
It states that smaller Type I muscle fibers are recruited first and de-recruited last during muscle activity.
Which muscle fibers are referred to as “Cinderella fibers”?
The small, Type I fibers that are constantly active during sustained, low-level contractions.
Why are “Cinderella fibers” more vulnerable to damage?
They are continuously activated, leading to metabolic overload and less recovery time.
What are two physiological consequences of overusing Cinderella fibers?
Increased risk of muscle damage and calcium (Ca²⁺) dysregulation.
What condition may result from prolonged overload of these fibers?
Formation of Myofascial Trigger Points (MTrPs).
What type of muscle overuse is commonly linked to trigger point formation?
Overuse in cervical and postural muscles during low-intensity activities and sedentary work.
What kind of activities typically cause this overuse in cervical and postural muscles?
Tasks that require precision and postural stability (e.g., computer work, dental work).
What is the suspected mechanism behind trigger point development?
Sustained low-level muscle contractions leading to reduced intramuscular perfusion.
What physiological problems result from reduced muscle perfusion?
Ischemia, hypoxia, and insufficient ATP synthesis, especially in type I muscle fibers.
How do ischemia and hypoxia contribute to trigger point formation?
They cause increased acidity, calcium (Ca²⁺) accumulation, and sarcomere contracture.
What does sarcomere contracture lead to?
Further reduction in perfusion and oxygen—creating a vicious cycle.
What may this vicious cycle ultimately result in?
The formation of Myofascial Trigger Points (MTrPs).
What happens during persistent nociceptive bombardment?
The dorsal root ganglion releases Substance P and CGRP antidromically into peripheral tissue.
What does “antidromic release” mean?
It means the substances are released in the opposite direction from normal (toward the periphery, not the CNS).
What is the effect of Substance P and CGRP in peripheral tissue?
They cause mast cell degranulation, vasodilation, and plasma extravasation.
What is plasma extravasation?
The leaking of fluid from blood vessels into surrounding tissues.
What is meant by a “sensitizing biochemical soup”?
A mix of inflammatory chemicals in tissue that lowers the threshold for pain and promotes inflammation.
