Psychosocial stress is a risk factor for the development of neck and shoulder pain, especially in women. The purpose of the study is to compare the effects of low and high levels of psychosocial stress on hormones responses and muscle activity during intermittent contractions of the cervicoscapular muscles in healthily females. Using 10-15 healthy female subjects, we will examine the effects of both high and low levels of psychosocial stress on neuromuscular activation and fatigue. The subjects will be instructed to perform a series of shoulder elevations in conjunction with a cognitive task in the form of a math problem. Each subject will complete a cycle of four intermittent contractions followed by a maximal contraction for the duration of a 30 minute time period. The subject will complete a total of two of the previously explained sessions. There will be EMG electrodes placed on the subjects' upper shoulder and back muscles. Surface EMG will be recorded in the left upper trapezius and levator scapulae muscles which we will use to determine how those particular muscles respond to both high and low stress conditions.