RT Journal Article
SR Electronic
T1 Muscle Quality, Architecture, and Activation in Cachectic Patients with Rheumatoid Arthritis
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP jrheum.090584
DO 10.3899/jrheum.090584
A1 Verena Matschke
A1 Peter Murphy
A1 Andrew B. Lemmey
A1 Peter J. Maddison
A1 Jeanette M. Thom
YR 2009
UL http://www.jrheum.org/content/early/2009/12/10/jrheum.090584.abstract
AB Objective To explore muscle-specific force (force per physiological cross-sectional area, or PCSA) and muscle activation in cachectic patients with rheumatoid arthritis (RA). Methods In 14 muscle-wasted patients with RA and age and sex matched healthy controls, vastus lateralis (VL) force and voluntary activation capacity were assessed during maximal isometric contractions with electromyography and superimposed electrical stimulations. VL PCSA was determined from ultrasound measures of fiber fascicle length (Lf), pennation angle, and volume, together with assessments of body composition by dual energy x-ray absorptiometry and objective physical function. Results Although patients with RA had reduced physical function, lower muscle mass, and VL volume relative to controls, there were no differences in muscle-specific force and activation. PCSA, force, and pennation angle tended to be lower in RA, with no differences in Lf. Conclusion Muscle-specific force and activation are not compromised and thus are unlikely to contribute to reduced function in cachectic patients with RA.