title: Resistance exercise improves muscle strength, health status and pain intensity in fibromyalgia--a randomized controlled trial.
abstract: BACKGROUND
  Fibromyalgia (FM) is characterized by persistent widespread pain, increased pain sensitivity and tenderness. Muscle strength in women with FM is reduced compared to healthy women. The aim of this study was to examine the effects of a progressive resistance exercise program on muscle strength, health status, and current pain intensity in women with FM.
  
  
  METHODS
  A total of 130 women with FM (age 22-64 years, symptom duration 0-35 years) were included in this assessor-blinded randomized controlled multi-center trial examining the effects of progressive resistance group exercise compared with an active control group. A person-centred model of exercise was used to support the participants' self-confidence for management of exercise because of known risks of activity-induced pain in FM. The intervention was performed twice a week for 15 weeks and was supervised by experienced physiotherapists. Primary outcome measure was isometric knee-extension force (Steve Strong®), secondary outcome measures were health status (FIQ total score), current pain intensity (VAS), 6MWT, isometric elbow-flexion force, hand-grip force, health related quality of life, pain disability, pain acceptance, fear avoidance beliefs, and patient global impression of change (PGIC). Outcomes were assessed at baseline and immediately after the intervention. Long-term follow up comprised the self-reported questionnaires only and was conducted after 13-18 months. Between-group and within-group differences were calculated using non-parametric statistics.
  
  
  RESULTS
  Significant improvements were found for isometric knee-extension force (p = 0.010), health status (p = 0.038), current pain intensity (p = 0.033), 6MWT (p = 0.003), isometric elbow flexion force (p = 0.02), pain disability (p = 0.005), and pain acceptance (p = 0.043) in the resistance exercise group (n = 56) when compared to the control group (n = 49). PGIC differed significantly (p = 0.001) in favor of the resistance exercise group at post-treatment examinations. No significant differences between the resistance exercise group and the active control group were found regarding change in self-reported questionnaires from baseline to 13-18 months.
  
  
  CONCLUSIONS
  Person-centered progressive resistance exercise was found to be a feasible mode of exercise for women with FM, improving muscle strength, health status, and current pain intensity when assessed immediately after the intervention.
  
  
  BACKGROUND
  ClinicalTrials.gov identification number: NCT01226784, Oct 21, 2010.
authors.affiliation: Institute of Medicine, Department of Rheumatology and Inflammation research, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan Box 480, 405 30, Göteborg, Sweden. anette.e.larsson@vgregion.se.|University of Gothenburg Centre for Person Centered Care (GPCC), Göteborg, Sweden. anette.e.larsson@vgregion.se.
authors.forename: Anette
authors.initials: A
authors.lastname: Larsson
authors.affiliation: Institute of Medicine, Department of Rheumatology and Inflammation research, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan Box 480, 405 30, Göteborg, Sweden. annie.palstam@gu.se.|University of Gothenburg Centre for Person Centered Care (GPCC), Göteborg, Sweden. annie.palstam@gu.se.
authors.forename: Annie
authors.initials: A
authors.lastname: Palstam
authors.affiliation: Department of Clinical Sciences, Danderyd Hospital, Karolinska Institute, Stockholm, Sweden. monika.lofgren@ki.se.
authors.forename: Monika
authors.initials: M
authors.lastname: Löfgren
authors.affiliation: Department of Dental Medicine, Karolinska Institute, Stockholm, Sweden. malin.ernberg@ki.se.
authors.forename: Malin
authors.initials: M
authors.lastname: Ernberg
authors.affiliation: Sahlgrenska University Hospital, Rheumatology, Göteborg, Sweden. jan.bjersing@rheuma.gu.se.
authors.forename: Jan
authors.initials: J
authors.lastname: Bjersing
authors.affiliation: Department of Clinical Sciences, Danderyd Hospital, Karolinska Institute, Stockholm, Sweden. indre.bileviciute-ljungar@ds.se.
authors.forename: Indre
authors.initials: I
authors.lastname: Bileviciute-Ljungar
authors.affiliation: Department of Pain and Rehabilitation Center, Linköping University, Linköping, Sweden. bjorn.gerdle@inr.liu.se.|Department of Medical and Health Sciences, Linköping University, Linköping, Sweden. bjorn.gerdle@inr.liu.se.
authors.forename: Björn
authors.initials: B
authors.lastname: Gerdle
authors.affiliation: Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden. eva.kosek@ki.se.
authors.forename: Eva
authors.initials: E
authors.lastname: Kosek
authors.affiliation: Institute of Medicine, Department of Rheumatology and Inflammation research, Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan Box 480, 405 30, Göteborg, Sweden. kaisa.mannerkorpi@gu.se.|University of Gothenburg Centre for Person Centered Care (GPCC), Göteborg, Sweden. kaisa.mannerkorpi@gu.se.|Institute of Neuroscience and Physiology, Section of Health and Rehabilitation, Physiotherapy, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden. kaisa.mannerkorpi@gu.se.
authors.forename: Kaisa
authors.initials: K
authors.lastname: Mannerkorpi
mesh_terms: D000328:Adult; D005081:Exercise Therapy / Q000379:methods; D005260:Female; D005356:Fibromyalgia / Q000175:diagnosis / Q000453:epidemiology / Q000534:rehabilitation*; D006304:Health Status; D006801:Humans; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D010146:Pain / Q000175:diagnosis / Q000453:epidemiology / Q000534:rehabilitation*; D010147:Pain Measurement / Q000379:methods*; D011788:Quality of Life; D012064:Relaxation Therapy / Q000379:methods; D055070:Resistance Training / Q000379:methods*; D016037:Single-Blind Method; D055815:Young Adult