Comparison Table of Posture and Repetitions Before and After Change in Burdened Task
Comparison Table of Posture and Repetitions Before and After Change in Burdened Task
If you have changed the workbench height, equipment, process, or auxiliary tools, do not just check 'Improvement Complete' How the posture, number of repetitions, and exposure time actually changed before and after the change It is best to leave them under the same standards.
Before and after equipment and process changes Work posture → Repetition count → Exposure time → Force/Weight → Work speed → Worker's opinion Compare them on the same unit. In particular, for the introduction of new tasks or equipment that fall under musculoskeletal burden work, or changes in the work environment such as workload or work processes, you must also check whether a hazardous factor investigation is necessary.
📎 Attachments to this post
After changing equipment, processes, and work methods Posture, number of repetitions, exposure time, weight/force, use of assistive devices We provide a separate Excel file to record changes before and after. This is not a form to replace the statutory hazardous factor survey form, but rather a supplementary document for internally comparing and reconfirming changes before and after improvement.
📌 Why do I need to record the 'before and after' separately?
In the investigation of musculoskeletal hazard factors, workplace conditions such as equipment, work processes, workload, and work speed, as well as working conditions such as working hours, posture, and work methods, must be verified. In particular, In cases where new work or equipment corresponding to musculoskeletal burden work has been introduced, or the work environment, such as the volume of work or work processes, has been changed In accordance with current safety and health regulations, a hazardous factor investigation must be conducted within one month by reviewing the subjects and methods of investigation.
Therefore, if you have improved equipment, adjusted workbench heights, rearranged processes, implemented automation, or introduced auxiliary tools, rather than merely leaving a record stating that improvements were made What has actually changed It is better to compare them.
🧭 Please create the comparison table in 5 steps.
- Fix the work unit first. Even if the process name is the same, if the detailed tasks differ, separate them into separate rows.
- Observe the conditions before the change. Record work posture, number of repetitions, work time, weight/force, work speed, and breaks/assistive tools.
- I will leave the details of the changes specifically. Instead of 'improvement of working environment,' use it like 'workbench height 72→82cm, move part box position closer to the torso.'
- Observe again based on the same criteria after the change. Compare using the same work cycle and observation time as much as possible.
- We check not only whether the figures have decreased but also whether new burdens have arisen. We also check for the risk of transition where waist bending decreases but shoulder elevation increases.
📋 Minimum items to compare before and after the change
| Comparison area | Content to be recorded before and after the change | Writing Tips |
|---|---|---|
| Neck and lower back posture | Bending, twisting, presence and duration of fixed posture | Record observable postures in detail rather than 'discomfort' |
| Shoulder and arm posture | Elbow height, degree to which arms are raised from the torso, whether overhead work is performed | If left and right are different, record each separately. |
| knees and squats | Squatting and knee-bending postures and exposure time | Check daily accumulated time as well as the single task |
| Number of repetitions | Number of times the same action is performed per minute or per work cycle | Use the same observation time before and after the change |
| Working time · Exposure time | Actual daily execution time, continuous work time | Distinguishing between waiting time and actual work time |
| Weight/Power | Handling weight, lifting, pushing, pulling, finger strength, etc. | If possible, record as a numerical value, such as kg or recovery. |
| Work speed | Hourly throughput, takt time, job cycle | Check if changes in productivity do not increase the burden again. |
| Auxiliary tools and equipment | Lift, height adjustment platform, handle, cart, etc. | Check not only installation status but also actual usage |
| Worker's opinion | Pain/discomfort, usability, new discomfort | Record based on work experience rather than medical diagnosis |
🔢 The number of repetitions must be counted using the 'same standard'.
If the observation time is different, such as 5 minutes before the change and 1 minute after the change, it is difficult to compare based solely on the number of times. Numbers/minute, Numbers per hour, Numbers per work cycle Choose one and record using the same criteria. If the workload itself has changed, it is recommended to also look at the total number of daily repetitions and the actual exposure time.
If the arm extension motion in the packaging process decreased from 18 times/minute before the change to 10 times/minute after the change, do not just note the 'decrease in repetitions,' but simultaneously check how the work speed, daily exposure time, and shoulder posture have changed.
🪑 Record posture as an observed fact rather than 'good/bad'.
| Records to Avoid | Recommended records |
|---|---|
| Poor back posture | The posture of bending forward at the waist when picking up parts is repeated in every work cycle. |
| Shoulder strain | The movement of the right elbow rising above shoulder height occurs approximately 8 times per minute. |
| Posture improved | After adjusting the workbench height, waist bending movements decreased from 12 times/min to 4 times/min. |
| Reduced strain on the wrist | The frequency of observed wrist bending posture decreased after changing the tool handle; worker discomfort was also confirmed. |
✅ Reconfirmation Checklist After Improvement
| Confirmation items | check |
|---|---|
| The same work unit was compared before and after the change. | □ |
| The observation time and units of the number of repetitions were standardized. | □ |
| We checked not only the work posture but also the workload, work speed, and work time. | □ |
| The conditions for the use of force, such as heavy objects, pushing, and pulling, were recorded. | □ |
| We verified that the auxiliary tool was not just 'installed' but was actually being used. | □ |
| We checked whether the improvement had increased the burden on other parts of the body. | □ |
| The opinions of the relevant workers were reflected. | □ |
| We separately verified the subjects of the hazardous factor investigation and whether a re-investigation was necessary. | □ |
| For items that remained a burden even after improvements, we set a deadline for additional measures with the person in charge. | □ |
⚠️ This comparison table alone does not complete the statutory hazardous factor investigation.
The attached comparison table is a practical reference material designed to quickly summarize changes before and after improvement. The Occupational Safety and Health Regulations stipulate that worker representatives or workers involved in the relevant tasks must participate in investigations of musculoskeletal hazards, and that appropriate methods, such as worker interviews, symptom questionnaires, and ergonomic surveys, must be used. In cases involving the introduction of new burdensome tasks or equipment, or changes to the work environment, the statutory investigation requirements and timing must be verified separately.
💬 When EAP support is needed
Safety and health measures take priority in improving work that places a burden on the musculoskeletal system. However, anxiety caused by recurring pain, the burden of workers' compensation, leave of absence, and return to work, as well as conflicts or stress arising from the job change process, may occur alongside these issues. While an Employee Assistance Program (EAP) can be provided as a supplementary measure to address these psychological burdens, it does not replace hazard assessments or improvements to the working environment.
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❓ FAQ
Q1. Is it mandatory to redo the hazardous factor investigation if the equipment is replaced?
Current Occupational Safety and Health Regulations stipulate that when new work or equipment classified as musculoskeletal burden work is introduced, or when the work environment—such as the volume of work or work processes—is changed, a hazardous factor investigation must be conducted within one month after reviewing the subjects and methods of the investigation. First, please verify whether the work in question qualifies as musculoskeletal burden work and confirm the scope of the changes.
Q2. How many minutes should the observation be repeated?
This comparison table does not define a single fixed observation time applicable to all tasks. The important thing is to select a section that represents the work cycle and apply the same standards before and after the change. If statutory investigation methods or professional ergonomic evaluations are required, the relevant standards must be applied separately.
Q3. My posture has improved, and my productivity has increased, leading to a rise in the number of repetitions. Can this be considered an improvement?
It is difficult to make a judgment based on a single indicator. It is advisable to examine posture, repetitions, force, exposure time, and work speed together to check whether reducing one risk has increased the burden on others.
Q4. May I submit the attached Excel file as the statutory hazardous factor investigation form?
This document is an internal supplementary form for comparison before and after changes. During statutory inspections, you must verify the hazardous factor investigation procedures and official investigation methods applicable to the workplace and prepare the necessary documents separately.
👉 Next step
When recording musculoskeletal strain before and after equipment and process improvements, please use the attached comparison table to record changes in posture, repetitions, and exposure time using the same criteria.
Inquire about Musculoskeletal & Work Environment Operations →📚 Source and Verification Criteria
- National Law Information Center · Articles 656–667 of the Rules on Industrial Safety and Health Standards
- National Law Information Center · Notification on the Scope of Musculoskeletal Burden Work and Methods for Investigating Hazardous Factors
This content and attached materials are practical reference materials for internally comparing and documenting changes to musculoskeletal burden work. They do not replace statutory hazardous factor investigations, ergonomic evaluations, or medical judgments. Additional evaluations may be required depending on the process and work characteristics of the workplace, and if necessary, a review by a safety and health or ergonomics expert is recommended. Date of legal verification: September 18, 2026.