Discomfort and pain from loaded passive joint structures.

: Sensations of strain and pain from healthy elbow and knee joints kept in an extreme position were reported on Borg's category-ratio scale (4) by 12 male volunteers in an experimental situation. The purpose of the study was to find out whether passive joint structures give sensations of discomfort and pain when moderately loaded for a certain time in an extreme position. Sensations of discomfort and pain were reported every 15th second. The mean values of ratings followed a straight line of increasing values during the first four minutes. Great variations were found between individuals. The elbow joint was six times more sensitive to the loading dose expressed as the product of the moment of force and time than was the knee joint. After the load was removed the provoked sensation slowly decreased. Sometimes the initial after-load rating was higher than the last rating with the load. The results imply that static work postures should also be analyzed with respect to joint position.