Assembly Line Ergonomics
An assembly line may ask the same hand, wrist or shoulder to repeat a motion thousands of times a shift. Small design problems that look harmless in a few minutes can cause lasting pain and injury over months. Good ergonomics fixes the job, not the worker.
- Manufacturing
- Assemblers
- Supervisors
Main risk factors
- Repetition: the same motion many times a minute. See Repetitive Motion.
- Force: pushing, pulling, gripping or pressing hard, such as driving screws or snapping parts.
- Awkward posture: reaching overhead or behind, bending the wrist, twisting the back.
- Static posture: standing or holding a position for long periods.
- Contact stress and vibration from edges and tools.
- Pace: machine-paced work with little recovery time.
These can lead to musculoskeletal disorders such as tendonitis and carpal tunnel syndrome. See Musculoskeletal Disorders.
Workstation fixes
- Keep work between waist and shoulder height, close to the body, in the easy reach zone.
- Use adjustable benches, lifts or turntables so workers of different sizes can work in neutral postures.
- Provide anti-fatigue mats, footrests or sit-stand stools for standing jobs.
- Place parts bins within reach, tilted for easy access, and keep heavy parts at waist height.
- Keep good lighting to avoid leaning in.
Tools and force
- Use balanced, lighter tools on arms or balancers so the worker does not hold the weight.
- Pick tools with handles that fit the hand and keep the wrist straight. See Anti-Vibration Gloves for vibrating tools.
- Use torque reaction arms for powered drivers so the worker does not absorb the twist.
- Add fixtures or jigs to hold parts rather than using the hand.
Work organization
- Job rotation between tasks that use different muscle groups.
- Short breaks and stretch breaks, and enough recovery time.
- New workers should build up to full pace gradually.
- Ask workers for ideas; they know where the problems are.
Report early
- Report numbness, tingling, aching or swelling at the first sign
- Ask for a workstation review if a task hurts
- Do not wait until the pain is constant
Your employer may be required to record work-related MSD cases. See Worker Rights.
Standards & references
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