Recent attempts to identify EMG elevations in patients with tension headaches have produced contradictory results. In the present case study, a 36-year-old male with a 17 year history of tension headaches was treated with trapezius EMG biofeedback while walking on a treadmill. The results demonstrated that: (1) EMG elevations could be identified during dynamic movement but not while in a static position and (2) EMG biofeedback during dynamic movement was effective in reducing EMG levels and headache activity. The results are discussed in terms of the potential importance of assessing and modifying patterns of elevated EMG activity which contribute to headaches during naturalistic activities such as walking.