TSTech Ergo-master Usage and Task Analysis

My Role/Contribution:

- Assessed the value of using Ergo-master in vehicle seat assembly tasks for lowering workers' musculoskeletal disorders.
- Determined the experimental plan and collected the workers’ performance data with the other students.
- Collected the analysis from the other researchers and visualized final result for the validation of conclusion.

Background

Ergo-master is a manual work positioner that allows 360 degrees rotation, up-to-a 90 degree tilt, and variable height adjustment.

It is expected to provide a safer, more comfortable and productive work environment and avoid the cost on shop floor injuries.

TS Tech, as a global supplier of automobile seats and interiors, are using the Ergo-master in their factory.

As a consulting service that's provided to TS Tech, the questions for us to answer:

The effectiveness of using Ergo-master for seat assembly tasks in ergonomics perspective?

What is the proper setting of the Ergo-master that brings the biggest benefit to the worker?

In situ:

Site visits to

observe the task and learn about the task from subject mater experts (workers, supervisors, safety professionals)
record videos of assembly task process

Data Analysis Stage I

Focus group and transcript analysis

Work organization

C-ring tool

Seat

Workers

Impression of Ergo-master

Offsite:

Collection of biomechanical and video data to characterize physical loads on the body

Testing conditions: Ergo-master height (depended on the participants' preference) and spin angle (13 & 32 deg)

Muscle activity recorded from right side:

Wrist muscles:

•Flexor carpi ulnaris

•Extensor carpi ulnaris

•Extensor carpi radialis brevis

Triceps

Shoulder muscles:

•Anterior deltoid

•Middle deltoid

•Upper trapezius

Video recordings were made and analyzed using semi-quantitative observational assessment tools (RULA/REBA, Strain Index)

Participants in task demo and Ergo-master testing

Data Analysis Stage II

REBA/RULA, Strain Index + Biomechanics

1. Mean muscle activities

Muscle activity was reduced from normal (task demo, red box) in several configurations using the spin feature of the Ergo-master (green box) .

2. Semi-quantitative analysis

Modified RULA/REBA + SI analysis

Biomechanics (based on different Ergo-master settings)

Suggestion of the most beneficial setting (Green cells + Lower EMG)

Interpretation of findings and suggestions

The c-ring job is physically stressful
Ergo-master use does not eliminate the risks from the job
- Although the spin feature of Ergo-master was effective
- Training and education would be needed to ensure the best set-up
Additional opportunities for job improvement:
- Effective job rotation and expansion
- Tool modification
- Tool suspension/unweighting