were put in the first group. The second group included all other operators regardless of how high their posture score was. While postural discomfort is frequently used as a guide to evaluating working postures and workplace fit, there is a wide variation in the length of time before operators perceive discomfort and in the level of discomfort which thev report. To have conducted these trials over a longer period would have provided higher score:; however, it is known that operators adjust their working post&e to relieve loading on areas wnicti are uncomfortable. A large number of subjects wouid have been required if this study was to test the relationship of the magnitude of a RULA score to the magnitude of pain, ache or discomfort. The aim of this study was to establish if the RULA scoring could reflect whether or not a working posture was in the acceptable range as defined earlier. The x2 statistical test was used to determine association between the subject’s score defined by grouping and any reported pain, ache or discom from that body part region. The results are givei Table 3. the this fort The relationship of the individual RULA body part scores to the development of pain or discomfort is statistically significant for the neck and lower arm scores (P < 0.01) and not significant for the trunk, upper arm or wrist scores. The statistical significance of the neck and lower arm body part scores reflects the high loading of these body parts while performing a VDU-based task. Functionally, the neck-shoulder region experiences static muscle fatigue contributed to by the load of the arms and their position” . The lower arm region includes the muscles and associated soft tissue structures responsible for the posture and action of the wrist, hand and fingers. The task required constant keying so that the structures in the neck and shoulder region were performing a static posture function while the structures of the forearm performed high repetition rate and low force finger movements with no recovery period over the 40 min trial. With these experienced data-entry subjects the loading of these structures was sufficient to cause reporting of discomfort or pain of a significant level. Further studies of other tasks commencing with cash till operators are planned to evaluate the different associations of individual body part discomfort with the musculoskeletal loading from the working postures adopted.
Functional units Assessing the effect of loading in all the structures when grouped as functional units would be achieved by relating posture scores A and B to the reporting of pain, ache or discomfort in the whole region. A y2 statistical test was again used and the operators’ rest& were grouped according to whether there was a posture score of 1 or a score greater than ! for both A and B scores. There was a highlv significant association (P < 0.01) between both posture scores A and B and reported pain or discomfort in the relevant functional unit regions (see Table 4). The high statistical significance of the relation