Movement times for a seated operator moving within and outside the Zone of Convenient Reach

An experiment was aimed at determining the effect of the location of the movement on the movement time taken. The movements were made within the normal working area (NWA), zone of convenient reach (ZCR) and outside the zone of convenient reach. The latter movements required trunk movement to reach the movement zone. It was found that movement time (MT) was dependent only on Fitts' Index of Difficulty (ID) for movements within NWA and ZCR, but was also dependent on the amplitude of the movement when outside the ZCR, where trunk motion was required. Significant differences in MT occurred between each movement zone. Movements between NWA and ZCR zones were not significantly different in time to those within these zones. Times for movement between the NWA and outside the ZCR were not different to those made outside the ZCR.

Relevance to industry: Times for making movements are dependent on the region forward of the person in which the movements are made. When making movements outside the zone of convenient reach, where the arm is fully extended, trunk movement is required and movement times are increased.