This group will receive subthreshold stimulation

This group will not receive any treatment

The study group received subthreshold stimulation via a two-channel portable electrical stimulation unit (BTL-4620, Czech Republic). Two self-adhesive electrodes (9 × 5 cm Axelgaard PALS, Axelgaard Manufacturing Co. Ltd., CA, USA) were used to deliver a premixed amplitude-modulated electrical current with 100 Hz frequency/pulse 60ms width. Four electrodes were placed on the quadriceps muscle to include all the muscle as follows: the first electrode was placed on proximal third, the the secod electrode was placed on middle third, the third electrode was placed on distal lateral third, and the fourth electrode was placed on the distal medial third. Before applying the electrodes, the skin of the anterior thigh was cleansed with alcohol to decrease the surface impedance. The intensity of the device gradually increased till the participant started to feel the electrical current. Then, the intensity was decreased by 10%. Therefore, the intensity is about 90% of the sensation threshold.

Lower limb muscle performance was measured using an isokinetic dynamometer (Biodex Medical INC., Shirley, New York, USA). It was used to assess peak torque, total work, average power, work fatigue percentage, and agonist-antagonist ratio. This instrument is a gold standard, valid, objective, and reliable system used in research, clinical testing, and rehabilitation

C-reactive protein blood test is a gold standard, reliable, and valid adequate operation technique (Spasovski and Sotirova, 2014). C-reactive protein is an inexpensive and readily available biomarker to assess systemic inflammation and clinical outcomes in RA. C-reactive protein is measured from a blood sample that comes from a vein. The result is expressed in milligrams per liter (mg/L). The report might indicate that the level is high, low, or normal. Most healthy adults have CRP levels lower than 0.3 mg/L. Clinical trials often specify elevated CRP for ≥6 mg/L (

The investigatorswill use the Health Assessment Questionnaire to measures functional disability through patient self-reports across eight categories (dressing, arising, eating, walking, hygiene, reach, grip, activities) using a 0-3 scale (no difficulty to unable to do)