Janitors are at a significant risk of injury due to lifting heavy trash bags. According to the Bureau of Labor Statistics, custodial workers experience higher rates of musculoskeletal disorders (MSDs) compared to many other occupations. Common injuries include strains and sprains, particularly affecting the back, shoulders, and arms.

Studies have shown that the handling of overweight trash bags and improper lifting techniques contribute to these injuries, with thousands of cases reported annually in the U.S. Using ergonomically designed tools and equipment, as well as implementing proper lifting practices can help reduce the incidence of these injuries.

Peer reviewed or academically grounded studies cited below address musculoskeletal injuries, lifting tasks, and ergonomic risks among janitors/custodians — including lifting heavy trash bags.

1. Risk of Musculoskeletal Disorders (MSDs) Among Janitors During Most Frequent Occupational Tasks — Aljaroudi A., Gomez S., England L. (2024). Study design: Surveyed janitors on workload, tasks, and injuries over two six-month periods, plus ergonomic analysis (REBA and Borg ratings) for common tasks. (See sidebar, “What is REBA?”)

2. Janitor Ergonomics and Injuries in the Safe Workload Ergonomic Exposure Project (SWEEP) Study — Schwartz A., Gerberich S.G., Kim H., et al. (2019). Applied Ergonomics.

Positive Gravity Waste Management (PGWM) is a term describing a process of waste management to potentially reduce injuries from lifting “heavy” waste bags. That term is in quotes since lifting trash weighing even <25 lbs. can cause injury per study #2 above. The process is described in four steps along with recommendations:

1. Keep it Light.

“Injury becomes more of a concern when bags become heavier. PGWM should provide options for janitors who have physical ailments (e.g., shoulder mobility or strength issues, back or knee issues) such as tailoring or limiting the amount of weight that can be lifted, enabling them to self-select how much waste to tie up per bag,” states Gary Allread, PhD, CPE, Ergonomics Technical Advisor to the Ohio Bureau of Worker’s Compensation.

Technology Recommendation: Manufacturers of waste and recycling receptacles can incorporate a simple weight scale into each waste bin, to enable at-a-glance when trash should be removed for disposal.

2. Let Gravity Assist.

Position large exterior dumpsters below the level of waste bag drops (e.g., at a loading dock) so lifting isn’t required.

Roll the receptable on its side and gently slide the bag from the container. If this is not possible, team lift to dispose of trash, bending at the knees not the back.

Technology Recommendation: Use ventilated trash containers to prevent suction resistance when emptying; note, this does not apply to bottom-access containers. Use rolling containers or carts to transport waste.

3. Use Bottom-access Containers.

Being able to remove trash from the bottom of receptables provides a potential ergonomic benefit — example, Longopac (Ref: Fas-Trak, Monee, IL) — with a few caveats.

“I’m not yet convinced that all bottom-access receptacles are better ergonomically. It seems in some cases they trade off lifting bags from the top (a possible issue for the shoulders, etc.) to having to bend over, tie off, and cut, and then lift bags from near floor level (a possible issue for the back),” notes Dr. Allread.

4. Avoid Bending and Twisting.

Whichever method of gravity assist you choose, it’s vital to go slow, exercise care, and avoid bending and twisting the body.

Conclusion

Implementing proper lifting practices and using ergonomic process and tools can help reduce the incidence of injuries.

We believe the data will show effective PGWM can reduce the effort to lift heavy trash bags from “Hard / Very Hard” to “Easy / Moderate” on the Borg CR-10 exertion scale, improve REBA scores (See sidebar, “What is REBA?”), and decrease the potential for MSDs among janitors. The same principle applies to recycling or Positive Gravity Recycling Management (PGRM).

(Image Credit: Fas-Trak, Monee, IL)

Sidebar

What is REBA?

A REBA (Rapid Entire Body Assessment) score is a numerical output (1-15) indicating musculoskeletal disorder (MSD) risk from a specific job task, with higher scores meaning higher risk, guiding immediate changes for very high scores (11+) and further investigation for medium scores (4-7). The assessment analyzes postures (neck, trunk, legs, arms, wrists) and factors like force and activity, combining them into a final score to prioritize interventions and improve worker health.

How it works

Assessment: A professional observes a worker performing a task, scoring body postures (neck, trunk, legs, arms, wrists), force/load, and activity.

Calculation: Scores for different body parts are combined using tables to create Score A (trunk/neck/legs) and Score B (arms/wrists), which then feed into a final Score C, adding the activity factor to get the total REBA score.

Range: Scores run from 1 (negligible risk) to 15 (very high risk).

What the scores mean (Action Levels)

1-2 (Negligible/Low Risk): No or minor changes needed.

4-7 (Medium Risk): Further investigation, changes soon.

8-10 (High Risk): Investigate and implement changes promptly.

11+ (Very High Risk): Implement changes immediately.

Why it’s used

To identify high-risk tasks needing ergonomic improvements.

To assess if changes (like new equipment or techniques) effectively reduce risk.

To promote better worker health and safety by making jobs more comfortable.