Sleepiness decreases alertness and results in decrements in performance. This is especially problematic in the healthcare field due to restricted sleep from shift-work. Sleepiness increases medical errors, but it also affects emotions and interpersonal interactions. Empathy in physicians is a desirable trait which is associated with increased patient recovery rates and patient satisfaction, and decreased use of pain medication. Shift-work may alter empathy in physicians and affect patient outcomes, but the effects of sleepiness on empathy are unknown. Empathy, which is related to burnout, declines during medical school, while incidence of burnout increases. This study assessed the effect of sleepiness from time of day (TOD) and 12 h shifts on empathy and burnout in medical students. Participants were tested on sleepiness and empathy prior to and immediately following a 12 h Emergency Medical Technician shift. Burnout was assessed following each shift to determine if it was affected by sleepiness, empathy, and shift. TOD affected empathy, with empathy highest in the evening. Sleepiness from working 12 h shifts resulted in decreased empathy and increased burnout, with females showing higher rates on the exhaustion component of burnout. This research demonstrates that TOD affects empathy, and sleepiness decreases empathy and increases burnout in medical students.

Weighting the arms during locomotion results in decreased swing motion and increased shoulder muscle activity. To determine the functional relevance of this activity, participants walked on a treadmill with the arms unweighted, or weighted unilaterally or bilaterally. Similar to past work, the weighted arms decreased in swing amplitude and increased their shoulder muscle activity. A close examination of shoulder muscle activities in specific regions of the arm swing cycle suggested these muscles primarily acted eccentrically for all weighting conditions. These findings suggest that the increased shoulder muscle activities when weighting the arms act to dampen the arms when the inertial characteristics of the arms are altered, as opposed to assisting in driving swing of the heavier arms.