Pain-Related Fear and Motor Control in Healthy Volunteers

The goal of this clinical trial is to learn how experimentally induced movement-related threat affects emotional, autonomic, and motor responses in healthy adults. The main questions it aims to answer are: * Does movement-related threat change walking performance or upper-limb pointing movements? * Are these effects moderated by participants' level of kinesiophobia? * Does movement-related threat increase apprehension or alter heart rate variability responses? Participants will complete two experimental conditions during one session: a control condition and an experimental condition. In both conditions, inactive transcutaneous electrical nerve stimulation (TENS) electrodes will be placed in the lumbar region. In the experimental condition, participants will receive verbal suggestions about discomfort, movement-evoked pain, and potential unpredictable electrical stimulation to create the threat of pain associated with movement. Participants will complete a baseline assessment of kinesiophobia, followed by walking and pointing tasks, while perceived apprehension and autonomic responses are assessed.

Inclusion Criteria: * Age between 18 and 65 years. * Ability to understand the experimental instructions and questionnaires. * No pain at inclusion and during the last 3 months. * Abstinence from short-term analgesics for 2 hours before testing. * Abstinence from coffee and cigarette smoking for 6 hours before testing. Exclusion Criteria: * History of chronic pain. * Motor, neurological, or sensory disorders. * Cardiovascular conditions likely to affect physiological measurements. * Clinically significant depressive symptoms or anxiety scores on the Hospital Anxiety and Depression Scale.