Manual de-blistering (packaging / manufacturing)
De-blistering is required to recover tablets from faulty blister packs.
This initially involves tearing cartons and literature, involving awkward wrist postures and undesirable force.
Manual de-blistering required operators to use forceful pinch grips, with the greatest force being exerted through the thumbs. Discomfort and other upper limb symptoms were commonplace after a shift involving de-blistering.
During the de-blistering task, the wrists were held in bent and awkward postures (ulnar deviation of the wrists), especially when not using the manual aid. When using the manual aid, there was also rotation and flexion of the supporting wrist as the strips of tablets must be turned; this occurred approximately every 6 seconds.
Operators sometimes placed boxes full of tablet strips onto their knees instead of the table, as the table was too high for them to comfortably work from. One operator chose to rest their wrists onto the edge of the box whenever possible, whilst another tilted the box towards her and rested the back of the box against the table; this also made accessing the strips of tablets a lot easier.
Both operators sat resting their feet on the bar underneath the table. This posture not only added to the difficulty in keeping the box balanced on their knees, creating extra tension, but it also meant that they could not comfortably place their feet flat onto the floor, leading to discomfort in the legs and back. Additionally all of the castors had been removed this meant that the operator could not move the seat once they had sat down.
The de-blistering task can be a long process, sometimes lasting an entire shift. Furthermore, it was reported that some operators find the task very monotonous and become fatigued and under-stimulated within this area.
Long term solution:
Ideally the necessity for de-blistering should be eliminated by improvements in the packaging process. When de-blistering is required an automatic de-blistering machine should be used which uses pneumatic punches to remove the tablets. This would eliminate the necessity for repetitive thumb movements and awkward seated postures.
Short term solutions included:
Implementation of several sized manual punching aids that can be used on a variety of tablet sizes. Using the manual aid reduces the force required during de-blistering.
An appropriate foot support was provided that allowed operators to adjust the seat to the appropriate height for working as well as being able to gain adequate support for the feet and legs; the chair foot-ring is not appropriate. Blister pack boxes were replaced with smaller bins which could be placed comfortably on the table, avoiding the temptation to rest it on the knees.
Regular breaks and job rotation was also introduced. It was advised that job rotation should include tasks which do not involve significant upper limb work or prolonged sitting.
- Introduction of a pneumatic punching machine or automation would eliminate the musculoskeletal risk.
- Manual aids reduce the amount of force required to deblister the tablets.
- Provision of suitable seating and foot supports allow operators to achieve a more comfortable working postures.