Stress is in fact the human emotion that one is not able to cope with the current situation. The result is a fight-and-flight reaction. One physiological reation when preparing to fight is the increase in muscle tension. As a result, it must be possible to estimate stress based on muscle activity, so by measuring EMG. There are strong indications that this is possible on the trapezius muscle, but this is only done in conditioned situations where we can impose stress and non-stress situations while emonitoring the relaxation of the muscle tension1) 2).