The objective of the study was to evaluate the physical
capacity and effort in patients with fibromyalgia. Muscle
strength and the coefficient of variation of the strength
measurements of 181 female fibromyalgia patients and 126
healthy females were compared. These measurements and
ergometer exercise capacity, work status and psychometric
scoring (SCL-90-R) were correlated.
The fibromyalgia patients exhibited significant reduction in voluntary
muscle strengthof the knee and elbow, flexors and extensors in the
order of 20-30%. However, the coefficient of variation was higher
among patients, thus indicating lower effort. The physical
performance during an ergometer test corresponded to a maximal
oxygen consumption of 21 ml/kg-1 x min-1. The maximal increase
in heart rate was only 63% (44-90%) of the predicted increase.
Degree of effort or physical capacity did not correlate to
psychometric scores. Work status was related to psychometric
scoring, but not to physical capacity or effort. In conclusion, we
found a low degree of effort but near normal physical capacity in
the fibromyalgia patients.