No Effect of a Single Session of Anodal Transcranial Direct Current Stimulation on Exercise-induced Hypoalgesia in Knee Osteoarthritis: A Randomized Cross-over Trial
Date
Authors
Toomey, David
Lewis, Gwyn
Rashid, Usman
Tuck, Natalie
Rice, David
Supervisor
Item type
Journal Article
Degree name
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley
Abstract
BACKGROUND: Exercise induces short-term pain relief (exercise-induced hypoalgesia, EIH), but this response is often blunted in people with knee osteoarthritis (OA). Transcranial direct current stimulation (tDCS) has been proposed as a potential enhancer of EIH. OBJECTIVE: This study aimed to determine whether a single session of 2-mA anodal tDCS applied for 20 minutes over the contralateral primary motor cortex augments the exercise-induced hypoalgesic response to isometric quadriceps exercise in individuals with knee OA. MATERIALS AND METHODS: In this double-blind randomized cross-over trial, 27 participants with knee OA completed two experimental sessions (active anodal tDCS + exercise; sham tDCS + exercise) in counterbalanced order. Pressure pain thresholds (PPTs at the knee and forearm), resting knee pain, and evoked knee pain during stepping were assessed pre- and post intervention. Linear mixed models compared pre- and postexercise changes between active and sham conditions. Blinding success was evaluated using Bang's blinding index. RESULTS: Both sessions produced EIH (knee PPT increased pre-to-post; all p ≤ 0.001). Between active and sham conditions, there were no significant differences for knee PPT (mean difference 0 kPa [95% CI -50 to 40], p = 0.82), forearm PPT (-20 kPa [-60 to 30], p = 0.45), resting knee pain (1/100 [-13 to 15], p = 0.89), or evoked knee pain (1/100 [-7 to 8], p = 0.14). Blinding was successful, and no adverse events were reported. CONCLUSIONS: These findings indicate that a single session of anodal tDCS does not augment the immediate EIH response to isometric quadriceps exercise in people with knee OA. PERSPECTIVE: This randomized cross-over trial found that anodal tDCS did not enhance EIH in people with knee OA. These findings suggest that a single session of anodal tDCS does not meaningfully augment the immediate exercise-induced hypoalgesic response in individuals with knee OA. CLINICAL TRIAL REGISTRATION: The Australian New Zealand Clinical Trials Registry number for the study is ACTRN12621000787886, registered July 1, 2021, prospectively.Description
Keywords
Clinical trial, exercise-induced hypoalgesia, knee osteoarthritis, pain, transcranial direct current stimulation, 32 Biomedical and Clinical Sciences, 3202 Clinical Sciences, Rehabilitation, Arthritis, Physical Activity, Neurosciences, Clinical Trials and Supportive Activities, Aging, Pain Research, Chronic Pain, Osteoarthritis, Clinical Research, 6.3 Medical devices, Musculoskeletal, 1103 Clinical Sciences, 1109 Neurosciences, 1702 Cognitive Sciences, Neurology & Neurosurgery, 3209 Neurosciences
Source
Neuromodulation, ISSN: 1094-7159 (Print); 1525-1403 (Online), Wiley, S1094-7159(26)00023-1-. doi: 10.1016/j.neurom.2026.01.011
Publisher's version
Rights statement
© 2026 The Authors. Published by Elsevier Inc. on behalf of the International Neuromodulation Society. This is an open access article distributed under the terms of the Creative Commons CC-BY license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. You are not required to obtain permission to reuse this article.