Book binding
This case study shows a worker placing the pages of a book into a machine, aligning the outer cover over the pages and pinching to bind the book together. Before reading this, it may be useful to read the "try it out" overview if you have not already.
Task description
- The worker places the pages of a book into a machine, aligns the outer cover over the pages and pinches to bind the book together.
- The work is self paced so the worker reports that she has no difficulty keeping up, and on average each binding takes about 18 seconds to complete.
- The worker reports that she applies a "moderate" amount of force to bind the pages together.
- The work day is from 07:45am to 16:30pm with one 15 minute break at 09:45 and a 30 minute break at 12:15. There are no other formal breaks.
- There is no job rotation, however, about every two minutes the worker removes the stack of books from the end of the conveyor belt. This takes about 10 seconds each time.
A video of a worker binding book pages.
Before you begin the assessment, watch the video for a few minutes to become familiar with the task and view the task from different angles.
Scores
Hover over individual rows for an explanation of each risk score.
A1. Arm movements
The arms move almost continuously. There are occasional brief pauses in arm movement, so this risk factor was not given the very highest score, but instead was scored Red 5.
A2. Repetition
There is an 18 second cycle time, and few similar motion patterns of either arm within the task cycle.
B. Force
The worker reports that the force required is moderate when binding the pages together. This force is applied infrequently (ie for less than 15% of the cycle time), so the score is Amber 1.
C1. Head / neck posture
The worker bends her head/neck forward for part of the time when using the binding machine
C2. Back posture
The worker bends her back forward when placing the bundle of pages into the binding machine. This only occurs for a very small part of the cycle time (less than 15%) and so is given an intermediate score of Amber 0.5
C3. Arm posture
The arms are raised away from the body when picking bundles of paper, aligning and binding the outer cover.
The arms are in an awkward posture for just less than half the cycle time (yet more than 30% of the cycle time), so an intermediate Amber 3 is scored.
C4. Wrist posture
The right wrist is bent for a part of the time when pressing the bind together and removing the book from the machine.
The left wrist is bent back when removing the book from the machine. This only occurs for a very small part of the cycle time and so is given an intermediate score of Amber 0.5
C5. Hand / finger grip
A pinch grip is used for more than half the time to grip the bundles of paper.
D1. Breaks
The longest duration of work without a formal break occurs between 12.45 and 4.30pm.
However, every 2 minutes, the worker moves away from the workstation to palletise the books, effectively providing a frequent short break from the task and an opportunity for recovery. For this reason, the factor is scored Green 0.
D2. Work pace
The worker sets their own pace of work and has no difficulty keeping up with the work.
D3. Other factors
The work is carried out in a well lit environment, and there are no other factors reported.
Task score
The task score, calculated for each arm separately, is the sum of the scores of all the risk factors.
For example:
5 + 0 + 1 + 1 + 0.5 + 3 + 0.5 + 2 + 0 + 0 + 0 = 13
D4. Duration multiplier
The worker performs the task for 8 hours per day, so the duration multiplier is 1.
Exposure score
The exposure score, calculated for each arm separately, is found by multiplying the task score by the duration multiplier.
For example:
13 x 1 = 13
The exposure score can be interpreted using the table of exposure levels.
Possible solutions to consider
Reduce force
Modifications to the gluing process might reduce the force required to bind the papers together.
Improve posture
Reducing the height of the paper stacks in front of the machine and on top of the cupboard would reduce the amount of reaching above shoulder and head height and improve arm posture. Providing a workbench so the paper stacks can be reached more easily could be an effective solution.