Functional capacity, muscle strength and falls in women with fibromyalgia

Background: Patients with fibromyalgia have difficulty with activities of daily living, they exhibit reduced muscle strength and high incidence of reported falls. The objective of this study was to evaluate the functional performance and lower limb muscle strength in women with fibromyalgia and determine the relationship between muscle strength and falls. Methods: Sixteen females with fibromyalgia and 16 healthy women participated in the study. Pain intensity, fibromyalgia impact on quality of life, physical activity level and fall prevalence were assessed. The peak torque and the rate of torque development were determined in maximal voluntary isometric contraction (hip, knee and ankle joints) using a load cell. The 30 s chair stand, 8 ft up and go, sit and reach, and functional reach tests were used to characterize functional performance. Findings: Women with fibromyalgia showed deficits in lower limb muscle strength, balance and agility and exhibited decreased knee extension peak torque and rate of torque development. In addition, they showed lower hip adduction and extension peak torque in comparison to the control group (P>0.05). Hip extension rate of torque development, duration of fibromyalgia symptoms, overall pain, knee pain, and fibromyalgia impact were strong predictors of the number of falls in patients with fibromyalgia (R2 = 0.86; P<0.05), when considered collectively. Interpretation: Women with fibromyalgia showed reduced functional performance and lower limb muscle strength, mostly explained by pain. There was a high prevalence of falls in this population, as explained by hip extensors rate of torque development, duration of fibromyalgia symptoms and pain. (C) 2011 Elsevier Ltd. All rights reserved.