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Status unknownNCT04240184IRMA21Updated Oct 31, 2022

Physical and Psychosocial Work Environmental Risk Factors of Low-back Pain

An observational study in Musculoskeletal Disorders and Stress, sponsored by National Research Centre for the Working Environment, Denmark. Status unknown at 1 site in Denmark. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2022-10-31.

Sponsored by National Research Centre for the Working Environment, Denmark · Observational

The sponsor has not verified this record recently (last verified Oct 2022), so the status shown — last known as Recruiting — may be out of date.
Study type
Observational
Model
Cohort
Time perspective
Prospective
Enrollment
400
Ages
18 Years and older
Sex
All
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Study summary

BACKGROUND:

Musculoskeletal disorders, and in particular low-back pain (LBP), are common among blue collar workers. In the work environment, both physical- and psychosocial risk factors exist. Working in warehouses in Denmark involve large quantities of occupational lifting, high work pace and a low degree of influence at work. This study investigates both acute and long-term associations between physical- and psychosocial work environmental factors and risk of LBP in warehouse workers. The specific study aims are to investigate 1) exposure-response associations between quantity of occupational lifting and short-term (day-to-day) changes in LBP, 2) the influence of accumulated workdays and rest days during a working week on LBP, 3) long-term association between occupational lifting exposure and LBP when assessed over 1 year, and 4) the role of psychological and social factors on the above associations.

METHODS:

The present study is designed as a 1-year prospective cohort study that will examine full-time warehouse workers from up to five retail chains in Denmark. Study aims 1 and 2 will be addressed using objective data based on company records with information on weight of all the goods handled by each warehouse worker during every single workday for 3 weeks. During this period, each worker will reply to text messages received before and after every workday (also on days off work) in which study participants will score their pain in the low back, bodily fatigue and perceived mental stress (scale 0-10). Long-term pain development is assessed using questionnaire surveys before and after 1 year. Further, pressure pain threshold (PPT) will be measured for selected trunk extensor muscles in approximately 50 workers using algometry along with measurements of maximal trunk extensor strength. Associations are modelled using linear mixed models with repeated measures between variables and LBP controlled for relevant confounders.

DISCUSSION:

This study provides knowledge about the acute and long-term associations between physical- and psychosocial work environmental factors and LBP. The obtained data will have the potential to provide recommendations on improved design of the working week to minimize the risk of LBP among warehouse workers, and may potentially enable to identify a reasonable maximum lifting threshold per day (ton lifted/day).

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Conditions studied

  • Musculoskeletal Disorders
  • Stress
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In context

Musculoskeletal Diseases

668 studies on the registry are indexed under Musculoskeletal Diseases; 161 are open to participants now.

This study's planned enrollment of 400 is above the median of 132 across 208 observational studies indexed under Musculoskeletal Diseases.

Browse Musculoskeletal Diseases studies →

Lead sponsor

National Research Centre for the Working Environment, Denmark is the lead sponsor of 23 studies on the registry; 1 is open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Sampling method
Non-probability sample

Study population

Enrolled study participants will receive a baseline questionnaire by e-mail that will address various aspects of physical-, psychological and social work environment and health. The questionnaire will also comprise an invitation to participate in a text message survey. Participants recruited for the text message survey will receive a SMS text message before and after every workday for 3 full weeks (21 days) to rate the magnitude of pain in their low back, and to score their current level of perceived physical fatigue and mental stress. During the same 3-week study period, section leaders at the warehouses will provide company records about the workload of each participating warehouse worker (goods handled by each worker, weight of the goods) along with a working schedule for each worker. One year after responding to the baseline questionnaire, the participant will be receiving a follow-up questionnaire

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • working ≥30 h per week in a registered retail industry warehouse
  • ability to read and understand Danish or English,
  • ≥18 years of age.

Exclusion criteria

Exclusion Criteria:

  • Hypertension > 160/100 mmHg
05

Study design

Observational model
Cohort
Time perspective
Prospective
Enrollment
400 participants (estimated)
Patient registry
No

Interventions

  • OtherPhysical workload

    Cohort study - The specific study aims are to investigate 1) exposure-response associations between quantity of occupational lifting and short-term (day-to-day) changes in LBP, 2) the influence of accumulated workdays and rest days during a working week on LBP, 3) long-term association between occupational lifting exposure and LBP when assessed over 1 year, and 4) the role of psychological and social factors on the above associations.

06

What researchers measure

Primary outcomes

  1. Short-term LBP

    exposure-response associations between quantity of occupational lifting and short-term (day-to-day) changes in LBP

    Time frame: 21 days

  2. Accumulated workdays and LBP

    the influence of accumulated workdays and rest days during a working week on LBP

    Time frame: 21 days

  3. Long-term LBP

    Long-term association between occupational lifting exposure and LBP when assessed over 1 year

    Time frame: 1 year

Secondary outcomes

  1. Psychosocial influence on LBP

    The role of psychological and social factors on outcome 1, 2 and 3

    Time frame: 21 days

07

Study locations

1 of 1 sites recruiting
  • National Research Centre for the Working Environment
    Copenhagen, 2100, Denmark
    Recruiting
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Oct 31, 2022, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT04240184
Lead sponsor
National Research Centre for the Working Environment, Denmark
Responsible party
Sponsor
First posted
Jan 27, 2020
Start date
Sep 1, 2021
Primary completion
Dec 1, 2022 (estimated)
Completion
Sep 1, 2023 (estimated)
Last update
Oct 31, 2022

Study contacts

Runi Blafoss, MSc
Contact
rub@nfa.dk
39165200 ext. 0045
Lars L Andersen, PhD
study director · National Research Centre for the Working Environment, Denmark
Runi Blafoss, MSc
principal investigator · National Research Centre for the Working Environment, Denmark

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is status unknown, as verified in Oct 2022. You cannot join it, but the record below documents what was studied.

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