A pilot study to determine whether differences exist in histochemical properties between the trapezius and extensor carpi radialis brevis muscles in women with work-related myalgia.
To investigate fibre-type abnormalities in women with work-related myalgia (WRM), tissue samples were extracted from their trapezius (TRAP) and the extensor carpi radialis brevis (ECRB) muscles and compared with healthy controls (CON). For the ECRB samples (CON, n = 6; WRM, n = 11), no differences (P > 0.05) were found between groups for any of the properties examined, namely fibre-type (I, IIA, IIX, IIAX) distribution, cross-sectional fibre area, capillary counts (CC), capillary to fibre area ratio, and succinic dehydrogenase activity. For the TRAP samples (CON, n = 6; WRM, n = 8), the only difference (P < 0.05) observed between groups was for CC (CON > WRM), which was not statistically significant (P > 0.05) when age was used a covariant. A comparison of the properties of these 2 muscles in the CON group indicated a higher (P < 0.05) and lower (P < 0.05) percentage of type I and type IIA fibres, respectively, in the TRAP as well as higher (P < 0.05) CC, which was not specific to fibre type. These preliminary results suggest that the properties employed to characterize fibre types do not differentiate CON from WRM for either the TRAP or ECRB. As a consequence, the role of inherent fibre-type differences between these muscles in the pathogenesis of WRM remains uncertain.
a Department of Kinesiology, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada.
Howard J
HJ
Green
Don
D
Ranney
Margaret
M
Burnett
Patti
P
Galvin
Natasha
N
Kyle
Sobia
S
Iqbal
David
D
Lounsbury
Jing
J
Ouyang
Ian C
IC
Smith
Riley
R
Stewart
Heather
H
Tick
A Russell
AR
Tupling
D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005542:Forearm; D006651:Histocytochemistry; D006801:Humans; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology*; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology*; D063806:Myalgia / Q000378:metabolism / Q000473:pathology*; D009784:Occupational Diseases / Q000378:metabolism / Q000473:pathology*; D010865:Pilot Projects; D013385:Succinate Dehydrogenase / Q000378:metabolism; D064171:Superficial Back Muscles / Q000378:metabolism / Q000473:pathology*
D013385:Succinate Dehydrogenase