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AB0973 The efficacy of electromyographic biofeedback on pain, function and maximal thickness of vastus medialis oblique muscle in patients with knee oa; a randomised clinical trial
  1. L. Sedighipour1,
  2. S.A. Raeissadat1,
  3. S.M. Rayegani2,
  4. Z. Bossaghzadeh1,
  5. M.H. Abdollahzadeh1,
  6. F. Malayi3
  1. 1Physical Medicine and Rehabilitation, Modarres hospital
  2. 2Tajrish square
  3. 3Physical Medicine and Rehabilitation, Shohada hospital, Tehran, Iran, Islamic Republic of Ireland


Background Isometric exercises play important role in treatment of Knee OA and are easy to do by the growing elderly population. Electromyographic (EMG) biofeedback devices are designed to enhance patient’s participation in these exercises by giving them feedback signals of visual or auditory nature, so that it can affect the subject’s voluntary activity.

Objectives The aim of this survey was to study the effect of EMG biofeedback on pain, function, thickness of the vastus medialis oblique muscle and maximal electrical activity of this muscle in isometric contraction, in patients with knee OA.

Methods In this single-blinded clinical trial, 46 patients aged between 45 to 70, referring to Shohadaye Tajrish and Shahid Modarres hospitals with diagnosis of knee OA, were recruited. Patients were randomlyassigned to two groups of case (23 patients), with EMG biofeedback associatedexercise, and control (23 patients), with sham biofeedback associatedexercise. The exercise program includes 12 sessions of 15 min isometric quadriceps exercise. Data were gathered via VAS score, the Persian version of WOMAC and Lequesne questionnaires, ultrasonography of VMO muscle and surface electromyography of this muscleat baseline and at the end of 2 months period of this study. Variables compared before and after exercises program in each group and between the two groups.

Results At the end of the study, there were no significant differences between the two groups regarding VAS score, VMO muscle electrical activity, maximal VMO muscle thickness, WOMAC and Lequesne questionnaires scores including overall scores and scores in each subcategories. Although all assessed parameters, except for VMO muscle thickness, were found to be improved significantly in each group, the changes were not more significant in case group except for the VAS score. VMO muscle thickness didn’t change significantly after 12 sessions of exercise in either of the groups.

Conclusions Isometric exercises accompanied by EMGBF and the same exercises with sham biofeedback for 2 months both lead to significant improvements in pain, and function of patients with knee OA. Real EMG biofeedback was not superior to sham biofeedback. The only parameter found to be improved to a greater extent in the EMGBF group was the subjective measure of VAS score.

Disclosure of Interest None declared

  • Knee osteoarthritis
  • Isometric quadricepsexercise
  • EMG biofeedback
  • surface electromyography
  • VMO thickness
  • knee pain
  • function

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