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

Objective: To investigate the effect of transcutaneous electrical nerve stimulation (TENS) on knee pain and comprehensive physical function in preradiographic knee osteoarthritis. Design: A single, participant-blinded, randomized controlled trial (RCT) with pre-post design. Setting: University research laboratory. Participants: Patients 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). Interventions: All 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 Measures: The 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. Results: Multiple 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). Conclusions: Use 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. (C) 2021 The Authors. Published by Elsevier Inc. on behalf of The American Congress of Rehabilitation Medicine. This is an open access article under the CC BY-NC-ND licensc (http://creativecommons.org/licenses/by-nc-nd/4.0/).