Oh, my aching… We all have to do repetitive movements or stay in a certain position for extended periods of time while at work (and at home too). Stretching the particular muscles associated with a certain position or movement helps to relax those muscles and avoid injury, fatigue and discomfort.
The Farm Safety Association, Inc. of Canada, with assistance from Ergonomics in Motion, have reproduced the stretching booklet. This 16-page booklet is on-line in both English and Spanish. It has great diagrams making it easy to follow and know which stretches to use.