The myalgia generate reasons for
(A) muscle nociceptors
The primary muscle pain often can occur in many disease conditions, can also occur in normal individuals under certain conditions. Clear reason for determining the nature and intensity of pain, is still not fully understood. Nociceptors in the muscle, is mediated by myelinated Ad fibers and unmyelinated C fibers are widely distributed in the muscle underwear, and other connective tissue, especially the combination of muscle and tendon, fascia and aponeurosis at. The most common pain mediators including: bradykinin, 5 – hydroxytryptamine, histamine, potassium and hydrogen ions. Characteristics of the mechanical stimulation of pain for fast, transient; chemical stimuli pain is manifested in the delayed, chronic pain.
(B) a common cause of pain
Muscle ischemia and
Excessive traction (including: pain, muscle spasm, contracture, reflex muscle spasm, muscle sheets by force higher)
Interstitial inflammation (such as: muscle fasciitis)
Muscle metabolic diseases (sugar, fat and mitochondrial disease)
Claudication interval syndrome, exercise induced muscle ischemia, muscle infarction
A. Mechanical and chemical factors
Toxic chemical factors can produce muscle pain, metabolic diseases such as inflammatory diseases and muscle. Compression or traction intramuscular connective tissue can produce muscle pain, such as intramuscular hematoma, infarction, spasm and muscle contracture. In contrast, muscle fiber necrosis and regeneration, such as muscular dystrophy, even if it is a very serious pathological changes, and rarely accompanied by myalgia. Of course there are some exceptions, such as muscular dystrophy, some showed only muscle pain after exercise, myalgia in BMD or FSHD may be a more common symptoms. However, the pathological changes in the degree of muscle pain and muscular dystrophy.
Although the eccentric contraction from a physiological point of view, is more effective than concentric contraction muscle eccentric contraction can lead to the disorder of the sarcomere and significant myalgia. Eccentric contraction-induced muscle pain and mechanical pressure and stretch-induced pain there is a difference. Eccentric contraction of the muscle can cause significant muscle ultrastructural changes, such as: Z-line disorders, water ripples, the destruction of the muscle fiber structure, as well as secondary changes, including intracellular edema, swelling of mitochondria, lysosomal activation and lipofuscin granules increased, the damage in the concentric contraction. Gleeson reported that the peak time of myalgia occurred in the first two days of the eccentric contraction, serum CK peak at 1-7 days after exercise, the C-reactive protein reached a peak in 1-11 days. Total white blood cell count, neutrophils, monocytes, basophils, compared with before exercise decreased by 15-20%, accompanied by iron, zinc, albumin, immunoglobulin G, M, decreased, while the lymphocytes , eosinophils, and platelet count did not change the above studies have shown that eccentric contraction of the acute inflammatory response may be associated with myalgia after exercise quickly, although there is muscle fiber necrosis, but no further muscle pathological changes .
Eccentric contraction injury due to muscle pain, anti-inflammatory painkillers. However, studies have shown that administration of L spin botulinum can reduce the onset of pain, reduce tenderness and lower CK levels, the principle is its expansion of blood vessels, and promote the clearance of the heterologous material.
Two. Ischemic muscle pain
In addition to affecting muscle, connective tissue can be caused by muscle pain, ischemia can also lead to skeletal muscle, cardiac pain. Caused by angina, intermittent claudication, by occlusive vascular disease. High-intensity exercise, ischemic muscle pain in normal subjects is also common, such as moving heavy objects arm pain. This ischemic myalgia specific mechanism remains unclear. This pain not seem to be caused by hypoxia due to ischemia caused by blocking the muscle blood supply did not increase muscle pain, and restore the blood supply can reduce the speed of pain, which indicates possible that some small molecules mediated such pain. , Epinephrine significantly increased in the ischemic muscle pain. If intra-arterial epinephrine can produce ischemic pain. In a comparative study found that caffeine, and adrenergic receptor antagonists can reduce ischemic muscle pain.
Muscle pain, not simply as fatigue due should be given attention, to prevent the misdiagnosis of the disease. Louis Vuitton Outlet Store