Increased proportion of megafibers in chronically painful muscles
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Increased proportion of megafibers in chronically painful muscles. / Andersen, Lars L; Suetta, Charlotte; Andersen, Jesper Løvind; Kjaer, Michael; Sjøgaard, Gisela.
I: Pain, Bind 139, Nr. 3, 31.10.2008, s. 588-93.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Increased proportion of megafibers in chronically painful muscles
AU - Andersen, Lars L
AU - Suetta, Charlotte
AU - Andersen, Jesper Løvind
AU - Kjaer, Michael
AU - Sjøgaard, Gisela
PY - 2008/10/31
Y1 - 2008/10/31
N2 - Trapezius myalgia - chronic pain from the upper trapezius muscle - is frequent in female employees in monotonous stressful jobs, potentially due to chronic overload of type I muscle fibers. In this study, we investigated the intra-individual distribution of trapezius muscle fiber size, and hypothesized that females with myalgia compared with matched healthy controls have a higher percentage of grossly hypertrophied type I fibers with poor capillarization. Forty-two female office workers with trapezius myalgia (MYA) and 20 healthy matched controls (CON) participated in the study. Standard histochemical methods were used to determine fiber size, fiber type, and capillarization. Type I megafiber were defined as at least twice the size of the median type I fiber size of each individual. The main finding was that MYA had a significantly higher proportion of type I megafibers than CON, in spite of no significant difference in overall type I fiber size. In MYA and CON type I megafibers were located in 46% and 11% of the females, respectively. Capillarization of the overall type I fiber pool was not different between CON and MYA, but was significantly lower in type I megafibers of both groups. The percentage of megafibers was positively related to age and weekly working hours, indicating an effect of long-term exposure. In conclusion, this study shows that trapezius myalgia is associated with a significantly higher percentage of grossly hypertrophied type I muscle fibers with poor capillarization - type I megafibers.
AB - Trapezius myalgia - chronic pain from the upper trapezius muscle - is frequent in female employees in monotonous stressful jobs, potentially due to chronic overload of type I muscle fibers. In this study, we investigated the intra-individual distribution of trapezius muscle fiber size, and hypothesized that females with myalgia compared with matched healthy controls have a higher percentage of grossly hypertrophied type I fibers with poor capillarization. Forty-two female office workers with trapezius myalgia (MYA) and 20 healthy matched controls (CON) participated in the study. Standard histochemical methods were used to determine fiber size, fiber type, and capillarization. Type I megafiber were defined as at least twice the size of the median type I fiber size of each individual. The main finding was that MYA had a significantly higher proportion of type I megafibers than CON, in spite of no significant difference in overall type I fiber size. In MYA and CON type I megafibers were located in 46% and 11% of the females, respectively. Capillarization of the overall type I fiber pool was not different between CON and MYA, but was significantly lower in type I megafibers of both groups. The percentage of megafibers was positively related to age and weekly working hours, indicating an effect of long-term exposure. In conclusion, this study shows that trapezius myalgia is associated with a significantly higher percentage of grossly hypertrophied type I muscle fibers with poor capillarization - type I megafibers.
KW - Adult
KW - Capillaries
KW - Case-Control Studies
KW - Chronic Disease
KW - Computers
KW - Female
KW - Humans
KW - Hypertrophy
KW - Middle Aged
KW - Muscle Fibers, Skeletal
KW - Muscular Diseases
KW - Neck Pain
KW - Occupational Diseases
KW - Pain
KW - Questionnaires
KW - Shoulder
U2 - 10.1016/j.pain.2008.06.013
DO - 10.1016/j.pain.2008.06.013
M3 - Journal article
C2 - 18701218
VL - 139
SP - 588
EP - 593
JO - Pain
JF - Pain
SN - 0304-3959
IS - 3
ER -
ID: 44914484