Types of injuries

Cumulative trauma and repetitive injuries

By the CalCompGuide editorial team · Last updated November 2026 · How we write and check guides

Common cumulative injuries

• Carpal tunnel syndrome and tendinitis (packing, assembly, typing, cooking, cleaning).
• Back, neck and knee damage from lifting, bending and standing on hard floors.
• Shoulder injuries from overhead work (construction, stocking, painting).
• Hearing loss from noise.
• Some heart, lung and stress-related conditions.

The date of injury

For CT, the date of injury is the date you first suffered disability (lost time or needed treatment) and knew, or reasonably should have known, that the condition was caused by your work (LC §5412). Often that's when a doctor first tells you your job caused it. This date matters because the 30-day notice and one-year deadlines run from it.

Which employer pays?

If you worked for more than one employer during the exposure, liability generally falls on the employer(s) and insurer(s) during the last year of injurious exposure before the date of injury (LC §5500.5). Name every employer from that period on your claim if you're unsure.

How CT claims are proved

CT claims rise or fall on medical evidence linking the condition to job duties. Help your doctor by describing your work precisely: how many hours a day you lift, how heavy, how many repetitions, what tools, how long you've done it. A written job description, photos of your workstation and coworker statements help.

Watch for these issues

• Specific vs. cumulative. A single incident can aggravate a CT condition; you may have both a specific and a cumulative injury. List both if that's what happened.
• Apportionment. Insurers often argue part of the disability comes from age or degeneration. The doctor must explain how much was caused by work.
• Claims after a layoff or firing. These are allowed in some situations, including when the date of injury for a CT falls after the termination notice, but they face extra rules (LC §3600(a)(10)). File as soon as you know.

This guide is general information, not legal advice. Every case is different. For free help from the state, call the DWC Information & Assistance unit at 1-800-736-7401.