This study evaluated the effects of three positions (reclining, standing, sitting) and four movements (leftand right cervical rotation; left and right lateral tilt) on the frontalis, sternocleidomastoid, and trapeziuselectromyographic (EMG) responses of 12 muscle contraction headache and 12 non-headache controls.While the headache group tended to show higher levels of muscle activity, position and movement effectswere much greater than headache group effects. Knowledge of kinesiology is required if one is tomeaningfully interpret muscular activity in the nonresting condition. The frontalis muscle was the musclewhich best discriminated headache and nonheadache groups. The reclining position was the position thatbest differentiated headache groups, suggesting an inability of headache subjects to relax even whenmuscle tension was not needed to maintain position. Results of the study have implications forassessments of muscular activity which deviate from the standard laboratory assessment which measuresonly frontalis EMG while the subject closes his eyes and rests in a recliner.