Immediate Effects of Transcutaneous Electrical Nerve Stimulation on Pain and Physical Performance in Individuals With Preradiographic Knee Osteoarthritis: A Randomized Controlled Trial

Abstract

ObjectiveTo investigate the effect of transcutaneous electrical nerve stimulation (TENS) on knee pain and comprehensive physical function in preradiographic knee osteoarthritis. DesignA single, participant-blinded, randomized controlled trial (RCT) with pre-post design. SettingUniversity research laboratory. ParticipantsPatients with knee pain belonging to Kellgren–Lawrence grade 0 or 1 (N=50; aged 50-69y) were randomly assigned to the TENS (n=25) and sham-TENS groups (n=25). InterventionsAll participants wore the TENS device under the patella of the symptomatic knee. After measurement, the TENS devices in the TENS group were turned on, and those in the sham-TENS group were not connected. Main Outcome MeasuresThe primary outcome measures included the stair climb test, timed Up and Go (TUG) test, 6-minute walk test (6MWT), and knee pain evaluated using the visual analog scale (VAS) for stair climb test, TUG test, and 6MWT. Secondary outcomes included knee extensor strengths and the 2-step test and stand-up test from the locomotive syndrome risk test. ResultsMultiple regression analysis revealed that TENS intervention significantly improved the walk distance and VAS score of the 6MWT, after adjusting for premeasurement data (distance; P=.015, VAS; P=.030). ConclusionsUse of TENS improved the VAS score for pain and the distance walked in the 6MWT for individuals with Kellgren–Lawrence grade 0 or 1 of the knee. Thus, TENS may be effective for long-distance walking in patients with preradiographic knee osteoarthritis.